Wet Conditions Research Articles

Variation of the nutritional content of different genotypes of Lotus corniculatus L. under optimum and sub-optimal soil moisture conditions throughout the seasons of the year

O Objective: To evaluate the leaf nutrient content of four accessions and one variety of Lotus corniculatus L. trefoil throughout the seasons of the year and under optimum and sub-optimal soil moisture content, established under a shade mesh in northern Mexico. Design/Methodology/Approach: During the 2021-2022 period, an experimental randomized block design, in a split-plot arrangement, with three replicates was established. The large plots had an optimum (26±1.5%) and sub-optimal (22±1.5%) soil moisture content. The small plots consisted of the trefoil accessions: 255301, 255305, 202700, 226792 origin code, and the Estanzuela Ganador variety. Results: At optimum soil moisture content, the 202700 accessions recorded a K deficiency throughout the year. Meanwhile, regardless of the soil moisture content, the 255301 accessions recorded a Mg and a Mn deficiency only in summer. N, P, Fe, and Mn recorded deficient contents: N and P throughout the year and Fe and Mn only in winter and spring. Study Limitations/Implications: These results could require a field validation, since the experiment was carried out in semi-controlled conditions, under shade mesh. Findings/Conclusions: Developing an adequate annual nutrition program for L. corniculatus L. that improves its forage productivity requires several key factors, including the behavior of the nutritional status (dependent on the type of nutrient), the growth stage of the plant, the season of the year, and the soil moisture content.

Effects of the Presence of Suberin in the Cork of Cerasus jamasakura (Siebold ex Koidz.) H. Ohba on the High Toughness Behaviour

Cork, the outermost tissue of bark, plays an important role in protecting trees from the surrounding environment and is used for various purposes, including flooring and insulation materials for buildings. This study focused on the amount and distribution of hydrophobic substances such as suberin and lignin in cork, as well as moisture conditions, to understand the mechanical properties of Cerasus jamasakura cork. Strips of cork were subjected to tensile tests after exposure to various moisture conditions (water-saturated, air-dried and oven-dried), and also after the desuberinisation and delignification of specimens. Cork with a high moisture content showed significant strain to the tensile load, whereas oven-dried specimens showed little toughness. The increased toughness of cork at higher moisture contents was due to the continued elongation in the plastic region, especially in the inner cork. The fibre length of the highly deformed cork differed significantly before and after the tensile test. Tensile tests of cork after desuberinisation and delignification indicated that the removal of suberin caused an earlier reduction in tensile properties than the removal of lignin. The presence of suberin in cork, distributed mainly in the inner cork, is believed to affect the tensile properties of cork.

Contrasting rhizosheath formation capacities in two maize inbred lines: implications for water and nutrient uptake

Abstract Background and aims Rhizosheath, the soil attached to plant roots, may enhance drought resilience by improving water and nutrient uptake. This study evaluates the effects of rhizosheath formation on water and nutrient absorption from soils with different textures and moistures. Methods Two maize inbred lines R109B (Rh +) and Ky228 (Rh-), known for their distinct rhizosheath formation yet having identical root morphology, were cultivated in loamy sand and loamy soils. When plants were 45 days old, a controlled soil drying cycle was initiated and parameters such as plant transpiration rate (E), leaf water potential ($${\psi }_{leaf}$$ ψ leaf ), and soil water content/potential were monitored. At the end of soil drying cycle, the total nutrient uptake in the plants’ shoots was assessed. Results Rh + demonstrated a denser rhizosheath, particularly in loamy sand, correlating with increased root hair development. Rh + plants in loamy sand had a 1.73-fold increase in normalized mass rhizosheath compared to loam soil. In moderate moisture, Rh + exhibited improved soil–plant-water relationships, evidenced by higher midday E and $${\psi }_{leaf}$$ ψ leaf in loamy soil than Rh-. However, no significant differences were noted under severe drought between Rh + and Rh-, likely attributed to diminished root hairs functionality. In loamy sand, Rh + plants exhibited 1.5 times higher phosphorus uptake, 1.46 times higher calcium uptake, and 2.02 times higher manganese uptake compared to Rh-. Conclusion Root hair development is a crucial factor in rhizosheath formation. The efficacy of the rhizosheath in enhancing water and nutrient uptake is significantly influenced by soil texture and moisture conditions.

Hakea decurrens invasion increases fire hazard at the landscape scale

AbstractHakea decurrens subsp. physocarpa is an invasive fire-adapted shrub of Australian origin that is quickly expanding in Portugal with potential impacts on fire behavior and fire regime. In this study we examined the effects of H. decurrens on fire hazard by assessing fire behavior indicators at the landscape scale, using a modeling and simulation approach. Six fuel models for H. decurrens were developed through fuel characterization and experimental fires. The fuel models correspond to combinations of developmental stages of H. decurrens populations (Early, Intermediate and Mature) and management (Standing and Slashed fuels). These combinations were used with three levels of H. decurrens invasion, corresponding to 25%, 50% and 75% of cover of the landscape, applied to five real landscapes in northern Portugal (replicates) under three fuel moisture conditions (Low, Medium and High), used as surrogates of weather severity. Fire behavior simulations were conducted with FlamMap software. The relationships between fire behavior indicators (flame length, rate of spread and burn probability) at the landscape level and the four factors tested were analyzed using Generalized Linear Mixed Models. Standing fuels were found to be more hazardous than slashed fuels. Fire-hazard increased with H. decurrens stand maturity and slash, regardless of moisture conditions. The results of this study indicate that H. decurrens expansion might negatively affect the fire regime in the north of Portugal. Our findings add to other known negative impacts of the species on native ecosystems, calling for the need to reinforce its control.

Multi-year climate memory in shallow lake water levels

Landscape hydrologic memory of meteorological cycles can have an important impact on catchment hydrological responses by propagating clustering of wet or dry conditions into extreme events. The non-linear and hysteretic hydrologic response functions driven by memory are often only studied at shorter temporal scales (event, season) despite larger interannual hydrologic responses evident in some systems. Within the Canadian Boreal, lakes and lake water levels provide an important indicator that can be used to assess the role of landscape memory on catchment hydrological function. Landscape memory has also been hypothesised to control the hydrological dynamics of shallow lake ecosystems that are also important biogeochemically and ecologically. Here we combine measurements of lake water levels in 26 lakes of varying type at varying temporal frequencies within the glaciated sub-humid Boreal Plain, to examine the impact and variability of interdecadal, decadal, multi-year, and intra-annual memory on lake water levels. We show multi-annual hysteresis of precipitation-lake water levels with varied characteristics in space and time. These spatial variations in landscape memory are driven by differences in storage capacities controlled by heterogeneity in glacial landforms, wetland-forest landcover and lake properties. Thus, the propensity for drought years or wet years to persist or accumulate into extreme landscape drying or wetting varies significantly between different lake-landscape characteristics. We show how landscape memory is crucial to project lake water levels by defining spatial variability of the impact of periods of meteorological drought and deluge vital for understanding system sensitivity, duration of recovery and in turn infer resilience on Boreal Plain hydrology.

Stable hydrogen isotope evidence of late-Holocene precipitation variability on the Caribbean slope of the Cordillera Central, Costa Rica

In Central America and the Caribbean, periods of increased aridity that correspond to the Terminal Classic Drought (TCD; 1200–850 cal yr BP) and the Little Ice Age (LIA; 500–100 cal yr BP) have been documented in many paleoclimate records. Compound-specific hydrogen (δDalkane) and carbon (δ13Calkane) isotopic compositions of n-alkanes in lake sediment can be used to interpret changes in paleoprecipitation and terrestrial paleovegetation, respectively. To assess the climate forcing mechanisms that drove the TCD and LIA, we established a multidecadal to centennial-scale late-Holocene reconstruction of precipitation variability and vegetation change at mid-elevation on the Caribbean slope of Costa Rica, developed from new δDalkane, δ13Calkane, and geochemical analyses and previous pollen and microscopic charcoal analyses from a sediment core from Laguna María Aguilar. Laguna María Aguilar is a freshwater lake located at 770 m elevation on the Caribbean slope of the Cordillera Central. During the TCD, δDalkane data for María Aguilar indicate relatively wet conditions compared to the mean δDalkane value for the entire record. Other proxy records for the TCD indicate that the Pacific slope of Costa Rica and sites above 3400 m near the continental divide experienced generally drier conditions than mid- and low-elevations on the Caribbean slope. We conclude that the TCD may have been driven by both Pacific and Atlantic climate-forcing mechanisms. During the LIA, the Laguna María Aguilar δDalkane record indicates an increase in hydroclimate variability, with some of the highest recorded δDalkane values (driest conditions) during the earliest portions of the LIA, but conditions were not persistently dry for the entirety of the LIA. Based on regional paleoclimate records overall, the LIA drought appears to be more clearly expressed on the Caribbean slope than on the Pacific slope of Costa Rica, indicating that the LIA was perhaps driven primarily by Atlantic Ocean conditions and climate dynamics.

Эффективность производства зерна в условиях изменения климата в Зауралье

Abstract. The economic efficiency of grain production is determined by the level of return on the resources spent by the cost of the products received. Weather factors play an important role. Climate changes in the Trans-Urals are primarily associated with the warming of the spring and summer months, increased aridity of the growing season and the expansion of the boundary of this process from the southeast to the northwest. The contrast in moisture availability of different years is combined with uneven precipitation in the region throughout the year. The profitability of farms in the production of grain crops is characterized by the same heterogeneity. The purpose of the study is to establish the economic efficiency of grain production in the context of climate change using the example of the Trans-Urals. The tasks are to analyze the impact of climate change on the yield of grain crops in the region, to analyze the efficiency of resource use by agricultural enterprises; using the example of the most highly profitable farms to identify factors to increase the efficiency of grain production. The methods of monographic and statistical analysis of data from scientific literature, open statistical sources, agronomic and economic reports of agricultural enterprises were used. The scientific novelty of the research consists in studying the efficiency of grain production in the context of climate change and in relation to the volatility of grain prices and means of production. The results of the study showed that since the early 2000s, despite a significant increase in the use of fertilizers, the growth of grain yields has stopped, which is primarily due to the deterioration of plant moisture conditions. At the same time, an increase in costs, although it leads to an increase in productivity, but to a lesser extent, as a result, the cost of grain increases, and the profitability of production decreases. Enterprises have been identified that, in the conditions of climate change and high volatility of grain prices and resources, have found ways to efficiently produce grain: replace solid fertilizers with liquid fertilizers, apply effective, including agrotechnical, methods of tillage and plant protection, use highly productive varieties, obtaining the highest profitability in the region.

Thermal Characteristics of Malaysian Khaya Senegalensis Wood Fuel Pellets: Densification-Induced Changes at Different Feedstock Moisture Levels

This study investigates the thermal behaviour of Malaysian Khaya senegalensis wood energy pellets, examining the effects of densification at different feedstock moisture levels. Densified wood pellets are promising renewable energy sources, but the impact of densification on thermal characteristics, considering various moisture contents, is underexplored. The main objective is to quantify the thermal characteristics, which involved proximate analysis such as energy pellets’ ash content, fixed carbon, volatile matter, and calorific value. In this research, Malaysian Khaya senegalensis wood was converted into pellets through a densification process, spanning from of 4-20% feedstock moisture levels. The manufactured pellets were then subjected to various tests to characterize the thermal properties. Results reveal compelling insights on the relationships between densification, moisture content, and thermal properties. Densification significantly influenced thermal attributes, with effects tied to initial moisture content. Varying moisture levels led to distinct thermal responses, reflecting interactions between densification-induced changes in moisture and thermal responses. In this study, the best moisture content for ash content was found to be 16%, with 3.24% ash content, 16% moisture content with volatile matter of 85.24%, fixed carbon of 12% from 20% moisture content, and 16% moisture content with calorific value of 19.65 MJ/kg. These findings aid Khaya senegalensis wood pellet densification optimization for improved thermal performance. Understanding densification's impact on thermal behaviour under varying moisture conditions enhances pellet efficiency as sustainable energy sources. This research contributes to biomass pellet knowledge for renewable energy applications, advancing efficient and eco-friendly energy solutions.

Study on the Structural Characteristics of Bulb Tubular Pumps Based on Fluid–Structure Interaction

As a special type of through-flow device, bulb turbine pumps have been widely used in the Eastern Route of the South-to-North Water Diversion Project due to their compact structure, flexible installation process, easy maintenance, high efficiency, and strong adaptability. Therefore, structural improvements to enhance their safety and stability through fluid–structure interaction analysis have significant engineering value. This paper conducts static and transient fluid–structure interaction analyses of the bulb turbine pump structure. The results show that the rotor structure experiences the greatest deformation under low-flow conditions, with maximum deformation (2.13 mm) occurring at the leading edge of the impeller inlet and decreasing radially along a gradient distribution. The damping effect of water changes the mode shapes of the rotor structure, and although the vibration modes under wet conditions are similar to those in the air, the frequencies decrease to varying degrees. In transient analyses under different conditions, the total deformation of the rotor system is greater than in static analyses, showing significant regularity. Under low-flow conditions, the deformation of the pressure surface at the inlet and outlet of the blade tip is greater than that of the suction surface, with a maximum total deformation of 3.656 mm. The maximum total deformation under design flow is 3.337 mm; under high flow, it is 2.646 mm. The total deformation of the casing mainly occurs on both sides of the internal bulb body bottom support, with a maximum deformation of 2.0355 mm and an equivalent stress maximum of 44.848 MPa. The equivalent stress and total deformation distribution of the support structure are similar, located at the top support and trailing edge, with a maximum value of 22.94 MPa at the trailing edge. The research results provide technical references and theoretical foundations for the structural optimization of bulb turbine pumps.

A Review of Drip Irrigation’s Effect on Water, Carbon Fluxes, and Crop Growth in Farmland

The substantial depletion of freshwater reserves in many pivotal agricultural regions, attributable to the dual pressures of global climate change and the excessive extraction of water resources, has sparked considerable apprehension regarding the sustainability of future food and water security. Drip irrigation, as an efficient and precise irrigation method, reduces water loss caused by deep percolation, soil evaporation, and runoff by controlling the irrigation dosage and frequency, thus improving the efficiency of water resource utilization. Studies have shown that compared with traditional irrigation methods, drip irrigation can significantly decrease water consumption, optimize the water–energy relationship by reducing soil evaporation, increase the leaf area index, and promote crop growth, thereby enhancing plant transpiration. Although more wet and dry soil cycles from drip irrigation may increase soil CO2 emissions, it also enhances crop photosynthesis and improves crop net ecosystem productivity (NEP) by creating more favorable soil moisture conditions, indicating greater carbon sequestration potential. The advantages of drip irrigation, such as a short irrigation cycle, moderate soil moisture, and obvious dry and wet interfaces, can improve a crop’s leaf area index and biomass accumulation, improve root dynamics, promote the distribution of photosynthetic products to the aboveground parts, and thus enhance crop yields. This study highlights the potential for the application of drip irrigation in arid regions where resource optimization is sought, providing strong technical support for the achievement of sustainable agricultural development. Future research needs to consider specific agricultural practices, soil types, and environmental conditions to further optimize the implementation and effectiveness of drip irrigation.

Toward rapid and efficient protocols: Synthesis of benzotriazole-based π-conjugated polymers via direct arylation polycondensation under aerobic conditions

π-Conjugated polymers (CPs) are widely used in the field of high-performance plastic electronics. However, the development of sustainable and efficient methods for synthesizing donor-acceptor (D–A)-type CPs remains challenging for their industrialization. In this study, we introduce a simple and rapid direct arylation polycondensation (DArP) technique for preparing various D–A benzotriazole-based π-CPs with high molecular weights under aerobic conditions in two hours. Additionally, the method demonstrates not only excellent yields but also copolymers with nearly defect-free structures. Via a minor modification involving the use of twenty or more equivalents of the base K2CO3 and refluxing the solvent, high molecular weight copolymers can be achieved in a short reaction time under oxygen and moisture conditions. Therefore, this finding presents a direct synthetic protocol that utilizes commercially available and air-stable catalyst precursors to produce high-quality π-CPs suitable for optoelectronic applications.

Probing the capacity of a spatiotemporal deep learning model for short-term PM2.5 forecasts in a coastal urban area

Accurate forecast of fine particulate matter (PM2.5) is crucial for city air pollution control, yet remains challenging due to the complex urban atmospheric chemical and physical processes. Recently deep learning has been routinely applied for better urban PM2.5 forecasts. However, their capacity to represent the spatiotemporal urban atmospheric processes remains underexplored, especially compared with traditional approaches such as chemistry-transport models (CTMs) and shallow statistical methods other than deep learning. Here we probe such urban-scale representation capacity of a spatiotemporal deep learning (STDL) model for 24-hour short-term PM2.5 forecasts at six urban stations in Rizhao, a coastal city in China. Compared with two operational CTMs and three statistical models, the STDL model shows its superiority with improvements in all five evaluation metrics, notably in root mean square error (RMSE) for forecasts at lead times within 12 h with reductions of 49.8 % and 47.8 % respectively. This demonstrates the STDL model's capacity to represent nonlinear small-scale phenomena such as street-level emissions and urban meteorology that are in general not well represented in either CTMs or shallow statistical models. This gain of small-scale representation in forecast performance decreases at increasing lead times, leading to similar RMSEs to the statistical methods (linear shallow representations) at about 12 h and to the CTMs (mesoscale representations) at 24 h. The STDL model performs especially well in winter, when complex urban physical and chemical processes dominate the frequent severe air pollution, and in moisture conditions fostering hygroscopic growth of particles. The DL-based PM2.5 forecasts align with observed trends under various humidity and wind conditions. Such investigation into the potential and limitations of deep learning representation for urban PM2.5 forecasting could hopefully inspire further fusion of distinct representations from CTMs and deep networks to break the conventional limits of short-term PM2.5 forecasts.

In Vitro Assessment of a New Block Design for Implant Crowns with Functional Gradient Fabricated with Resin Composite and Zirconia Insert.

This study aims to evaluate and compare the mechanical resistance, fatigue behavior and fracture behavior of different CAD/CAM materials for implant crowns. Eighty-eight implant crowns cemented-screwed with four sample groups: two monolithic G1 Zirconia (control) and G3 composite and two bi-layered G2 customized zirconia/composite and G4 prefabricated zirconia/composite. All static and dynamic mechanical tests were conducted at 37 °C under wet conditions. The fractographic evaluation of deformed and/or fractured samples was evaluated via electron microscopy. Statistical analysis was conducted using Wallis tests, which were performed depending on the variables, with a confidence interval of 95%, (p < 0.05). The Maximum Fracture Strength values displayed by the four groups of samples showed no statistically significant differences. The crown-abutment material combination influenced the failure mode of the restoration, transitioning from a fatigue fracture type located at the abutment-analog connection for monolithic materials (G1 and G3) to a brittle fracture located in the crown for bi-layered materials (G2 and G4). The use of layered crown materials with functional gradients appears to protect the crown/abutment connection area by partially absorbing the applied mechanical loads. This prevents catastrophic mechanical failures, avoiding long chairside time to solve these kinds of complications.

Improved thermal stability and electrical conductivity of dysprosium doped barium zirconium cerate electrolyte

Acceptor-doped perovskites based on the BaCeO3 have been extensively investigated as promising candidates for proton-conducting electrolyte at intermediate temperatures. This operational regime is characterized by proton conduction facilitated via hydroxyl protons that effectively occupy vacancies of oxide ions within the perovskite crystal lattice structure. While the trade-off parameters (proton conductivity and chemical stability) concern the utility of cerium-based electrolytes, acceptor doped compounds hinder the mobility of protons due to dopant-charge and dopant-host interactions. However, Dy-doped compounds reveal a promising behavior relative to most acceptor substituents with marginal constraints at higher doping concentration. As a result, a threshold doping range is essential to combat material inconsistencies such as cationic disorder to proton trapping effect. Therefore in the present study we synthesize the single-phase dysprosium and zirconium co-doped barium cerate at different doping concentrations (BaCe0.8-xZr0.2DyxO3-δ (x = 0.0–0.20)) to showcase the chemical inertness of the compound against oxidizing and reducing atmospheres preserving high ionic conductivity. According to our experimental outcomes, higher ionic conductivity among wet atmospheric conditions suggests the role of moisture to contribute additional charge carriers among the Dy-doped samples via explicitly generated oxygen vacancies. As a result, BaCe0.65Zr0.2Dy0.15O3-δ demonstrates a highest total conductivity, reaching 2.44 x 10-2 S cm−1 at 575 °C, with an associated activation energy of 0.61 eV within the temperature range of 300–600 °C. The study also reveals the optimal operating temperature of the proton conducting electrolyte to avoid mixed ionic (H+ and O2–) conduction.

Current limitations and future research needs for predicting soil precompression stress: A synthesis of available data

Precompression stress, compression index, and swelling index are used for characterizing the compressive behavior of soils, and are essential soil properties for establishing decision support tools to reduce the risk of soil compaction. Because measurements are time-consuming, soil compressive properties are often derived through pedotransfer functions. This study aimed to develop a comprehensive database of soil compressive properties with additional information on basic soil properties, site characteristics, and methodological aspects sourced from peer-reviewed literature, and to develop random forest models for predicting precompression stress using various subsets of the database. Our analysis illustrates that soil compressive properties data primarily originate from a limited number of countries. There is a predominance of precompression stress data, while little data on compression index or recompression index are available. Most precompression stress data were derived from the topsoils of conventionally tilled arable fields, which is not compatible with knowledge that subsoil compaction is a serious problem. The data compilation unveiled considerable variations in soil compression test procedures and methods for calculating precompression stress across different studies, and a concentration of data at soil moisture conditions at or above field capacity. The random forest models exhibited unsatisfactory predictive performance although they performed better than previously developed models. Models showed slight improvement in predictive power when the underlying data were restricted to a specific precompression stress calculation method. Although our database offers broader coverage of precompression stress data than previous studies, the lack of standardization in methodological procedures complicates the development of predictive models based on combined datasets. Methodological standardization and/or functions to translate results between methodologies are needed to ensure consistency and enable data comparison, to develop robust models for precompression stress predictions. Moreover, data across a wider range of soil moisture conditions are needed to characterize soil mechanical properties as a function of soil moisture, similar to soil hydraulic functions, and to develop models to predict the parameters of such soil mechanical functions.

Association between precipitation and mortality due to diarrheal diseases by climate zone: A multi-country modeling study.

Precipitation could affect the transmission of diarrheal diseases. The diverse precipitation patterns across different climates might influence the degree of diarrheal risk from precipitation. This study determined the associations between precipitation and diarrheal mortality in tropical, temperate, and arid climate regions. Daily counts of diarrheal mortality and 28-day cumulative precipitation from 1997 to 2019 were analyzed across 29 locations in eight middle-income countries (Argentina, Brazil, Costa Rica, India, Peru, the Philippines, South Africa, and Thailand). A two-stage approach was employed: the first stage is conditional Poisson regression models for each location, and the second stage is meta-analysis for pooling location-specific coefficients by climate zone. In tropical climates, higher precipitation increases the risk of diarrheal mortality. Under extremely wet conditions (95th percentile of 28-day cumulative precipitation), diarrheal mortality increased by 17.8% (95% confidence interval [CI] = 10.4%, 25.7%) compared with minimum-risk precipitation. For temperate and arid climates, diarrheal mortality increases in both dry and wet conditions. In extremely dry conditions (fifth percentile of 28-day cumulative precipitation), diarrheal mortality risk increases by 3.8% (95% CI = 1.2%, 6.5%) for temperate and 5.5% (95% CI = 1.0%, 10.2%) for arid climates. Similarly, under extremely wet conditions, diarrheal mortality risk increases by 2.5% (95% CI = -0.1%, 5.1%) for temperate and 4.1% (95% CI = 1.1%, 7.3%) for arid climates. Associations between precipitation and diarrheal mortality exhibit variations across different climate zones. It is crucial to consider climate-specific variations when generating global projections of future precipitation-related diarrheal mortality.

Development of a composite using calcined bone powder and silane cross-linked alginate as bone substitute material.

Calcined bone is an attractive natural material for use as a bone substitute because of its cost-effectiveness and high biocompatibility, which are comparable to that of synthetic hydroxyapatite. However, the calcination process has significantly weakened the mechanical properties. In this study, a composite of calcined bovine bone powder reinforced with silane cross-linked alginate was prepared to assess its biocompatibility, osteoconductivity, and mechanical compatibility as a bone substitute material. Culture studies with osteoblast-like cells (MC3T3-E1) showed no cytotoxicity toward the composite and exhibited general cell proliferative properties in its presence. In contrast, the composite reduced the alkaline phosphatase activity of osteoblasts but led to significant noncellular apatite deposition on the surface. In addition, quasi-static compression tests of the composite revealed mechanical properties comparable to those of human cancellous bone. The mechanical properties remained stable under wet conditions and did not deteriorate significantly even after 2 weeks of immersion in simulated body fluid at 37°C. The results show that this composite, composed of calcined bone powder and silane cross-linked alginate, is a promising bone substitute material with biocompatibility, osteoconductivity, and mechanical compatibility.

Quantitative MRI post-processing algorithm and visualization research based on moisture status detection of winter jujube

Quantitative Magnetic Resonance Imaging (qMRI) offers precise measurements of the relaxation characteristics of microstructures, representing a cutting-edge method in non-destructive fruit analysis. This study aims to visualize information on changes in moisture status and distribution at the subcellular level of winter jujube. The 0.5 T nuclear magnetic imaging equipment was utilized to rapidly, non-invasively, and accurately capture the internal relaxation status of the sample with multiple-echo-imaging. By examining the signal and noise data, a simulated dataset was developed to tackle the optimization challenge of estimating parameters for the discrete relaxation model from the multiple-echo-imaging data, especially under conditions of low signal-to-noise ratio (SNR) and in the context of heteroscedastic noise. An optimal weighting factor and the T2NR truncation model have been identified to establish an effective experimental inversion strategy. Subsequently, multiple-echo-imaging can rapidly and stably yielded voxel-level maps under conditions of low signal-to-noise ratio. Utilizing this experimental approach, data from winter jujube was collected and analyzed, facilitating an exploration of water activity (T2 mapping) and associated water content (A2 mapping). Through analyzing winter jujube fruits across two maturity stages, this study elucidates the role of precise quantification and voxel-wise visualization in moisture status detection. The methodology presents an innovative approach for assessing internal moisture distribution in fruits.

Mercury deposition in central China from the Last Glacial Maximum to the early Holocene recorded in an accurately-dated stalagmite

Characterization of transport pathways and depositional changes in Mercury (Hg) and their connection to climatic and environmental changes on various time scales are crucial for better understanding the anthropogenic impacts on the global Hg cycle in the Anthropocene epoch. In this study, we examined Hg variations recorded in a stalagmite from central China, covering the period from 25.5 to 10.9 thousand years ago. Our data show a marked increase in Hg concentrations during the late Last Glacial Maximum, which coincided with the period of highest dust deposition on the Chinese Loess Plateau. Hg concentrations were lower during Heinrich events 1 and 2 and the Younger Dryas but higher during the Bølling-Allerød and the early Holocene. We suggest that regional dust load, which enhances atmospheric dry deposition of Hg, is the primary factor influencing Hg deposition in central China on glacial-interglacial timescales. On millennial-to-centennial timescales, climate also plays a significant role. Warmer and wetter conditions increase vegetation, litterfall, and soil/rock weathering, which in turn boost mineral dissolution and soil erosion in the vadose zone. These processes collectively result in higher Hg concentrations in the stalagmite.

Lattice Boltzmann simulation of counter-current imbibition of oil and water in porous media at the equivalent capillarity

The characterization of oil and water displacement in porous media often relies on the capillary number (Ca = μv/σ cos θ). However, limited investigations have been conducted to explore the relative significance of interfacial tension and wettability in determining oil recovery, particularly under the imbibition mode. To address this research gap, the modified color gradient lattice Boltzmann method has been employed. This study aims to systematically investigate the transient imbibition characteristics, pore-scale events, and morphological features of the two-phase distribution in the matrix, all under the same capillarity but varying capillary numbers. The obtained results indicate that, for a given capillary number, a more water–wet condition generally leads to a higher imbibition recovery. Conversely, the influence of capillary number on oil recovery is complex and contingent upon the capillarity value, i.e., the interfacial tension between oil and water. Additionally, the oil recovery data from all cases have been effectively fitted using the Minkowski functionals, demonstrating a linear correlation. Moreover, an attempt has been made to elucidate the mechanism behind the varying oil recovery observed in different capillarity combinations. This analysis considers factors such as energy conversion, the transient change of the ratio of viscous force over capillarity, and the capillary valve effect. The findings of this study contribute to our understanding of the use of chemical agents to enhance oil recovery and provide valuable insights for determining key two-phase parameters in reservoir simulations.