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Efficiency of phosphorus fertilizers: research results in long-term field experiments in Russia, Great Britain and China

The results of research in long-term field experiments on the effectiveness of phosphorus fertilizers are presented. All experiments were based on the classical scheme and included, in addition to the control variant (without fertilizers), a nitrogen-potassium background, on which the effectiveness of phosphorus fertilizers was studied. At the same time, regional specifics were taken into account in each experiment: liming at the Experimental Station of the All-Russian Research Institute of Agrochemistry (Russia), the effectiveness of phosphorus fertilizers at increasing doses of nitrogen N100–300 at the Rothamsted Experimental Station (Great Britain), a combination of phosphorus fertilizers with manure at the Chinese National Soil Fertility Monitoring Base. In long-term experiments, the dynamics of changes in the content of mobile phosphorus, as well as individual fractions, taking into account the emerging balance of P2O5, are presented. It is shown that the redistribution of phosphorus between different soil fractions is reversible, and the direction of the processes depends on the emerging balance of P2O5. Phosphorus accumulated in more firmly held forms can subsequently be released and absorbed by cultivated crops. In all field experiments an increase in the yield gap between NK and NK + P variants was observed over time. On the one hand, this is due to a significant decrease in the phosphorus content in the background NK variant (in acidic soils – also an increase in Al mobility), in which phosphorus removal significantly exceeds control (without fertilizers), on the other – a significant increase in the content of P2O5 in the soil with a positive balance. In a long-term experiment at the Experimental Station of the Institute of Agrochemistry, the difference coefficient of phosphorus utilization from fertilizers was 25–27, at the Rothamsted station – 25–41, at the Chinese National Soil Fertility Monitoring Base – 45%. Attention is drawn to the high payback of phosphorus fertilizers in experiments at the Rothamsted experimental station (Great Britain) – 22–39 kg of grain/kg of P2O5 (when cultivating winter wheat in crop rotation). The main method of increasing payback in this case was the use of high doses of nitrogen – up to 200 kg N/ha. Studies have shown that liming acidic soils to a slightly acidic reaction, the use of zinc micronutrients, as well as phosphate-mobilizing microorganisms, are essential methods to increase the effectiveness of phosphorus fertilizers.

Drying: A Practical Technology for Blueberries (Vaccinium corymbosum L.)—Processes and their Effects on Selected Health-Promoting Properties

The global dried blueberry market is steadily growing, driven by the creation of innovative blueberry-based products. This trend presents an opportunity to explore a previously untapped segment of the blueberry market in Chile. In this study, a comprehensive assessment of four drying techniques (hot-air drying [HAD], vacuum drying [VD], infrared drying [IRD], and freeze-drying [FD]) was conducted to determine best operating conditions and preserve the health-promoting properties of blueberries. Drying kinetics, proximate composition, color, anthocyanin content, individual phenols, and antioxidant, antiproliferative, and antidiabetic potential of blueberries were evaluated. VD showed the highest drying rates, reaching equilibrium moisture more rapidly (Deff value of 3.44 × 10−10 m2/s). Drying caused an increase in lipid content but a decrease in protein content. The color parameter L* increased in all dried samples, and C* reflected color intensification. FD best retained anthocyanin content, which decreased significantly in the other drying processes. Chlorogenic acid and rutin predominated in HAD, IRD, and FD samples. The antioxidant potential in ORAC assays increased for all drying methods but decreased in DPPH assays. Blueberry extracts from FD and HAD exhibited the greatest antiproliferative effect against A549 and H1299 cell lines, respectively. HAD showed the best inhibitory effect on α-glucosidase, with an IC50 value of 0.276 mg/mL, similar to acarbose (IC50 = 0.253 mg/mL). Given the significant retention of health-promoting properties and bioactive compounds in HAD-dried samples, this method is advisable as a sustainable option for drying blueberries in Chile.

Impact of Laser Remelting Parameters on the Microstructure and Properties of Sprayed Ni20Cr Coatings with Rhenium Addition

The study was focused on the characterization of microstructural evolution and microhardness in the plasma-sprayed and laser remelted Ni-Cr coatings with 20% addition of rhenium on stainless steel. The remelting process was performed with different laser power and laser traverse speed. The laser remelting process improves the quality of plasma sprayed Ni-Cr-Re coatings, reducing the porosity and the inhomogeneity of the chemical composition. The remelted coatings were characterized by a dendritic microstructure. Microsegregation of rhenium to dendrites was observed. The remelted coatings have an iron content of over 40%, which is the result of too deep remelting with the substrate material. The iron content in the remelted coatings increases with the decrease in laser speed, but the rhenium content decreases. All tested coatings were characterized by hardness similar to that of the substrate material.

Process Optimization Using Cuckoo Search Algorithm for the Manufacturing of Resin Transfer Moulded Composite Parts

An in-house coded cuckoo search (CS) optimization algorithm integrated with a finite element simulation model was developed for resin transfer moulding (RTM) process optimization. At first, the mould filling and curing phases, the vital stages of the RTM process were modelled in the COMSOL multi-physics simulator for RTM6 resin – carbon fibre reinforced composite part. Then, the model was imported to the CS optimization algorithm scripted in MATLAB using the COMSOL live link for MATLAB. The CS algorithm was developed for the minimization of dry spot content by finding the optimal positions of gates and vents during the mould-filling stage and the minimization of the thermal gradient by finding the optimal mould temperature during the curing stage. From the optimization results, there was a decrease in dry spot content and thermal gradient with an increase in generations. With the generations, converged-stable-optimal solutions were obtained. A dry spot content of 3% for one gate and one vent and 0.56% for two gates and one vent was obtained for two-dimensional and three-dimensional composite plates, respectively. From the curing phase optimization results, a minimum thermal gradient of 0.86 K with 98.1% degree of cure was obtained for the optimal mould temperature of 433 K. The developed CS algorithm predicted the better-automated mould-fill and cure phase optimal solutions for the studied composite part.

Effects of Nutritional Support with a Leucine-Enriched Essential Amino Acid Supplement on Body Composition, Muscle Strength, and Physical Function in Stroke Patients Undergoing Rehabilitation

Background/Objectives: Dietary protein intake can potentially influence renal function. This study aimed to elucidate the association between dietary protein supplementation and a decrease in the estimated glomerular filtration rate (eGFR) in Japanese stroke patients undergoing rehabilitation. Methods: From July 2017 to June 2021, 60 patients undergoing post-stroke rehabilitation were randomly assigned to a rehabilitation alone or rehabilitation nutrition group, which received 120 g Reha-Time Jelly® after each session. Both groups were followed up for 3 months. Serum nutritional markers (prealbumin and retinol-binding protein), muscle strength, body composition, renal function markers (eGFR based on creatinine [eGFR-Cr] and cystatin C [eGFR-Cys]), urinary protein-to-creatinine ratio (UPCR), and motor function (walking speed, 2-min walk distance, and chair stand test) were assessed at baseline and post-intervention. Results: Of the 60 participants (mean age: 70.2 ± 10.0 years), 39 were men (65.0%) and 19 (31.7%) had chronic kidney disease. Initial eGFR-Cr and eGFR-Cys values were 70.5 ± 17.2 and 66.6 ± 14.8 mL/min/1.73 m2, respectively. After the intervention, the rehabilitation nutrition group demonstrated a significantly greater increase in body mass index (BMI) and a smaller decrease in bone mineral content than the rehabilitation alone group. However, no significant between-group differences were noted in serum marker levels or motor function, including grip strength and knee extensor strength, on the paralyzed and non-paralyzed sides. The change in chair stand test performance indicated a trend toward improvement in the rehabilitation nutrition group. No significant differences were observed in the changes in renal function. Conclusions: A 3-month nutritional supplementation intervention may help increase BMI, preserve bone mineral content, and support physical activity levels in patients undergoing post-stroke rehabilitation without negatively affecting renal function.

Influence of the Reduction Rate of Slag from Oxidation Process of Cu–Fe–Pb Alloy During Reduction (De-coppering) on Its Viscosity

AbstractThe production of copper based on a direct-to-blister flash smelting process made it necessary to introduce the technology for the reduction of flash smelting slag and subsequent refining of the resulting Cu–Fe–Pb alloy. Refining of Cu–Fe–Pb alloy produces a converter slag containing 7 ÷ 25 wt pct Cu, 3 ÷ 20 wt pct Fe , and 15 ÷ 45 wt pct Pb. This material is directed to the reduction (de-coppering) process, which allows the recovery of copper in the form of Cu–Pb alloy as well as the removal of lead from the copper material cycle in the form of lead-bearing material. The copper recovery rate in the form of Cu–Pb alloy depends on a number of factors, of which one of the primary ones is the viscosity of the medium (slag), which determines the rate of coalescence and sedimentation of the reduced metal droplets. The investigations on how the degree of reduction of metal oxides from the converter slag affects its viscosity are presented in the study. Viscosity tests were conducted in the range of 1000 ÷ 1450 °C and showed that the main factor affecting viscosity is the Cu2O content in the slag. Slags directed to the reduction process with a high Cu2O content have a lower viscosity than slags after the reduction process, which is due to a decrease in the copper oxide content of the slag. The viscosity of slags after reduction depends on the PbO content, the higher the PbO content the lower the slag viscosity. Furthermore, studies have shown that the viscosity of slags can be reduced by adding CaO to the slag.

Искажение геометрии, окисление кромки, структурные изменения и морфология поверхности реза листового проката толщиной 100 мм из алюминиевых, медных и титановых сплавов при плазменной резке на токе обратной полярности

The introduction describes the feasibility of using reverse polarity plasma cutting to produce large-sized non-ferrous metal blanks up to 100 mm thick. Data on the use of plasma cutting with direct and reverse polarity currents for thick sheet metal and the main technological problems associated with its implementation are presented. The purpose of the work is to study the organization of the structure and properties of the near-surface zone, changes in the chemical and phase composition when cutting aluminum, copper and titanium alloys. The research methods are optical and scanning electron microscopy, microhardness measurement, X-ray diffraction and energy-dispersive analysis. Plasma cutting was carried out using air as a plasma-forming and shielding gas, simultaneously with water injection into the discharge chamber and the formation of a “water fog” around the plasma column. Results and discussion. It is shown that both the arc stability and the shape of the plasma column are of great importance in reverse polarity plasma cutting of rolled sheets. The distortion of the cutting geometry during normal operation is greatest in the central part, and with insufficient heat input it shifts to the lower part and increases significantly. The operation of the plasma torch in air does not lead to significant changes in the composition of the cutting surface of aluminum and copper alloys. A decrease in the magnesium content near the edge is typical for the aluminum alloy in the surface layers. Cutting of the titanium alloy is accompanied by intense oxidation of the surface, especially in areas of difficult metal displacement from the cutting cavity. The formation of titanium oxides, mainly rutile Ti2O, sharply increases the microhardness values in the surface layers, which negatively affects the machinability of the cutting edge and requires shot blasting to remove the oxide layer. The conclusion describes the main patterns of implementing reverse polarity plasma cutting of sheet metal from aluminum, copper and titanium alloys with a thickness of 100 mm.

Effect of Mg content on corrosion resistance of Zn-11Al-XMg coatings

Zn-Al-Mg is one of the most important coating types in hot dipped galvanization. This surface coating also provides surface barrier protection and galvanic protection, which improves the esthetics and service life of the material. In this paper, the corrosion resistance of Zn-11Al-XMg coatings with Mg content (wt. %) of 0, 1, 2, 3 was studied, and the effect of Mg content on the corrosion resistance of Zn-11Al-XMg coatings was analyzed. The results show that Zn-11Al coating is composed of an eutectoid Al-rich phase and a Zn-rich phase. When the Mg content is less than 2 wt. %, the increase of Mg content is accompanied by the decrease of the Al-rich and Zn-rich phases and the increase of the ternary eutectic content. When the Mg content is more than 2 wt. %, the increase of Mg content is accompanied by the decrease of the ternary eutectic content and the increase of the primary MgZn2 phase content. The results of corrosion experiments show that the Zn-11Al-XMg coating is mainly composed of an Al-rich phase and an Mg2Zn11 phase in ternary eutectic as the main anode. The coating after adding Mg forms a denser corrosion product film, among which the Zn-11Al-2Mg coating close to the eutectic point has the best corrosion resistance.

The Potential of the Probiotic Isolate Lactobacillus plantarum SS18‐50 to Prevent Colitis in Mice

ABSTRACTThe objective of this study was to investigate the effect of the Lactobacillus plantarum (L. plantarum) SS18‐50 (an isolate with favorable probiotic properties following space traveling) on dextran sulfate sodium (DSS)‐induced colitis in mice. Male ICR mice were randomly assigned to one of six groups: a control group, a model group, and four intervention groups comprising the isolate (SS18‐50‐L and SS18‐50‐H) and the wild type (GS18‐L and GS18‐H) strains. The model group and the intervention groups were administered a 3.5% DSS (w/v) solution to induce acute enteritis. The four intervention groups were administered the corresponding bacterial suspensions, SS18‐50‐L (1.0 × 107 CFU/mL), SS18‐50‐H (1.0 × 109 CFU/mL), GS18‐L (1.0 × 107 CFU/mL), and GS18‐H (1.0 × 109 CFU/mL). The results demonstrated that the disease activity index (DAI) score of the SS18‐50‐H was markedly lower than that of the CON. Subsequently, the colon tissue of mice was analyzed to determine the levels of myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione (GSH), and malondialdehyde (MDA). The results demonstrated that all strains within the intervention groups exhibited good performance to prevent colitis. Particularly, the SS18‐50‐H strain exhibited a pronounced stimulative effect on GSH, an increase in SOD activity, and a decrease in MPO activity and MDA content. The SS18‐50‐H treatment resulted in a notable elevation in serum somatostatin (SS) levels and a concomitant reduction in endothelin (ET) and substance P (SP) levels, which approached normal ranges. The results of the RT‐qPCR analysis demonstrated that the mRNA expression levels of tumor necrosis factor (TNF‐α), cyclooxygenase (COX‐2), interleukin (IL‐10), and interleukin (IL‐6) in the SS18‐50‐H were significantly reduced to levels comparable to those observed in the CON. In conclusion, L. plantarum SS18‐50 has been demonstrated to inhibit the development of colitis in a dose‐dependent manner, thereby establishing it as a high‐quality lactic acid bacterium with a colitis inhibitory effect.

An R2R3‐type MYB transcription factor, GmMYB77, negatively regulates isoflavone accumulation in soybean [Glycine max (L.) Merr.

SummarySoybean [Glycine max (L.) Merr.] is an exceptionally rich in isoflavones, and these compounds attach to oestrogen receptors in the human body, lessening the risk of breast cancer and effectively alleviating menopausal syndrome symptoms. Uncovering the molecular mechanisms that regulate soybean isoflavone accumulation is crucial for enhancing the production of these compounds. In this study, we combined bulk segregant analysis sequencing (BSA‐seq) and a genome‐wide association study (GWAS) to discover a novel R2R3‐MYB family gene, GmMYB77, that regulates isoflavone accumulation in soybean. Using the soybean hairy root transient expression system, we verified that GmMYB77 inhibits isoflavone accumulation. Furthermore, knocking out GmMYB77 significantly increased total isoflavone (TIF) content, particularly malonylglycitin, while its overexpression resulted in a notable decrease in contents of malonylglycitin and TIF. We found that GmMYB77 can directly binds the core sequence GGT and suppresses the expression of the key isoflavone biosynthesis genes Isoflavone synthase 1 (GmIFS1), Isoflavone synthase 2 (GmIFS2), Chalcone synthase 7 (GmCHS7) and Chalcone synthase 8 (GmCHS8) by using dual‐luciferase assays, electrophoretic mobility shift assays and yeast one‐hybrid experiments. Natural variations in the promoter region of GmMYB77 affect its expression, thereby regulating the malonylglycitin and TIF contents. Hap‐P2, an elite haplotype, plays a pivotal role in soybean breeding for substantially enhanced isoflavone content. These findings enhance our understanding of the genes influencing soybean isoflavone content and provide a valuable genetic resource for molecular breeding efforts in the future.

Low-Molecular-Weight Organic Acid as an Alternative to Promote the Rooting of Persimmon Rootstock Shoot Cuttings.

Organic acids are naturally present in plants and exert a positive influence on plant development, which justifies surveying their potential effect on adventitious root (AR) formation. In this study, 0.0298 mol/L (4000 mg/L) of malic acid and 0.0267 mol/L (4000 mg/L) of tartaric acid were used to explore the effects of low-molecular-weight organic acid on the rooting of persimmon rootstock Diospyros lotus L. during cutting propagation. After organic acid treatment, the rooting percentage and the survival rate significantly increased, accompanied by a greater development of lateral roots. Anatomical analysis revealed that Diospyros lotus L. exhibits characteristics that induce root primordia, and organic acid treatment can enhance the differentiation of root primordia. Furthermore, treatment with organic acid led to a substantial decrease in soluble sugar and starch contents, along with a slight increase in soluble protein content during early cutting stages. Additionally, the indole-3-acetic acid (IAA) content peaked in the early stages of AR formation and was significantly higher than that of the control, while abscisic acid (ABA) levels exhibited the opposite trend. Comparatively, gibberellic acid (GA3) remained at extremely low levels throughout the rooting process in the organic acid groups compared to the control. In conclusion, the current study uncovers the anatomical structure over time during AR formation, revealing the dynamic changes in the related main nutrients and hormones and providing new ideas and a new practical approach for improving root regeneration in persimmon rootstock cuttings.

Decolorizing of seaweed extract by electrocoagulation

Electrocoagulation (EC) is a technique commonly used in wastewater treatment to remove biological and chemical contaminants, but the process has the potential to be used in clarifying plant extracts for the isolation and identification of secondary metabolites. Seaweed extracts contain copious amounts of chlorophyll and other pigments that obscure the characterization of secondary metabolites such as phenolic acids and flavonoids. In place of conventional methods that utilize solvents, EC can potentially be applied to clarify and fractionate extracts. In this research, an EC duration of 30 min (22 V, 0.3–0.5A) with aluminum electrodes resulted in a significant decrease, about 76%, of chlorophyll and 70% of carotenoids from seaweed extract measured at 666 nm and 410 nm. The decrease in extract green and yellow color intensity also mirrored a decrease in total phenolic content (TPC) of the extract from 54 ± 1.55 mg GAE/g DW to 3.2 ± 0.01 mg GAE/g DW after 30 min of EC. However, the phenolic acid profile of the extract after electrocoagulation via HPLC-RP indicated the removal of an interference probably caused by polymeric compounds from the extract, thus leaving the simple phenolic acids in solution for detection. The major phenolic acids detected in seaweed crude extract were p-coumaric, o-coumaric, ferulic and syringic acid. Flavonoids detected included catechin, epicatechin, quercetin-3-glucoside and rutin. The results of this study show the potential of replacing conventional plant extract purification methods with a green method that requires no additional solvent.Graphical

Multi-omics analysis and longitudinal study of reprogramming by dietary creatine to endogenous metabolism in largemouth bass (Micropterus salmoides).

Creatine is a feed additive with physiological pleiotropic properties and also an energy homeostasis protector in vertebrates and is successfully used in terrestrial livestock and aquaculture. Here, two feeding trials were performed to investigate dietary creatine on endogenous creatine metabolism and physiological reprogramming in largemouth bass. The results showed that the endogenous creatine metabolism genes AGAT, GAMT, and SLC6A8 of largemouth bass are highly conserved with the amino acid sequences of other teleosts and are clustered separately from mammals. Among the 16 major tissues in largemouth bass, both creatine synthesis genes (agat, gamt) and transporter gene slc6a8 are most highly expressed in muscle. Muscle has a high threshold but sensitive creatine negative feedback to regulate endogenous creatine metabolism. Dietary creatine intake significantly inhibits endogenous creatine synthesis and transport in muscle in a dose-dependent manner, and this inhibitory effect recovers with a decrease in dietary creatine content. In addition, physiological creatine saturation required prolonged exogenous creatine intake, and it would be shortened by high doses of creatine, which provides guidance for maximizing economic benefits in aquaculture. Metabolome and transcriptome showed that dietary creatine significantly affected the metabolism of the creatine precursor substance-arginine. Exogenous creatine intake spared arginine that would otherwise be used for creatine synthesis, increased arginine levels, and caused reprogramming of arginine metabolism. Overall, these results demonstrate that the addition of creatine to largemouth bass diets is safe and recoverable, and the benefits of creatine intake in largemouth bass are not limited to enhancing the function of creatine itself but also include a reduction in the metabolic burden of essential amino acids to better growth performance.

The Impact of Piriformospora indica on plant heat and drought tolerance

In recent years, the global rise in temperatures has led to drought and heat becoming major environmental stresses that limit plant growth. Previous research has demonstrated the potential of Piriformospora indica in augmenting plant stress resistance. However, specific studies on its effects and underlying mechanisms in cuttings of Rosa chinensis, Jasminum sambac, and Rhododendron simsii Planch are relatively limited. The objective of this study is to explore the effects and mechanisms of P. indica on cuttings and tissue-cultured seedlings of these plants under conditions of drought and high-temperature stress. The experiment involved subjecting P. indica-inoculated and non-inoculated plants to drought (one week without watering) and high-temperature (24-hour exposure to 45°C) stress in a controlled environment chamber. Indicators such as chlorophyll content, chlorophyll fluorescence parameter Fv/Fm, and antioxidant enzyme activity were measured. The results showed that inoculation with P. indica significantly increased the survival rate of the three types of plant cuttings under drought conditions by 13%, 17%, and 16.6% respectively, and resulted in a substantial decrease in malondialdehyde content alongside an increase in chlorophyll content. Under high-temperature stress at 45°C, the chlorophyll fluorescence parameter Fv/Fm values increased by 27.3%, 10.3%, and 51.1% compared to the control group. Furthermore, heat tolerance tests at 42°C showed a 2% higher survival rate in the P. indica inoculated Rhododendron tissue-cultured seedlings than in the control group, with a positive effect observed on the activities of superoxide dismutase and peroxidase. These findings demonstrate that inoculation with P. indica significantly enhances the resistance of Rhododendron, Jasminum sambac, and Rosa to drought and high-temperature stresses, providing insights for sustainable agricultural development and the comprehensive exploitation of the potential value of P. indica.

Influence of high‐iron bauxite on phase composition, microstructure, and properties of bauxite‐based homogenized grogs

AbstractInvestigation on the occurrence state of Fe2O3 in bauxite and its effect on the bauxite‐based homogenized grogs (BHG) is crucial for the utilization of high‐iron bauxite resources. BHG with different Fe2O3 contents incorporated in the form of high‐iron bauxite was prepared by maintaining the Al2O3 content around 82%. The effect of high‐iron bauxite addition (0, 25, 50 75, 100 wt.%) on the phase composition and microstructure evolution was studied using X‐ray diffractometer, scanning electron microscope, and Factsage software. The results show that part of the Fe2O3 in BHG is dissolved into crystalline phases, while the other part is present as a glass phase. The addition of high‐iron bauxite, coupled with a reduction in the SiO2 content, results in a rise in the corundum content within BHG from 55.0% to 93.6% and a decrease in the mullite content from 44.0% to 2.8%. This change results in a decline in the refractoriness under load of T0.6, dropping from 1593.5°C in the sample without high‐iron bauxite to 1430.7°C in the sample with 100% high‐iron bauxite addition. The microstructure of BHG evolves from the interconnected network of corundum and mullite phases to the structure of corundum bonded by the glass phase.

Temperature During Convective Drying of Thin Flat Wet Materials

. The basic laws of the kinetics of drying thin flat materials during the period of drop in the drying speed are outlined. A method for calculating the average integral temperature of wet material on the basis of the relative temperature coefficient of drying is presented. Experimental data are processed based on the relative drying rate in the drying processes of ceramics, asbestos, and woolen fabric. A formula for calculating the average temperature is proposed. The solution of the differential equation of thermal conductivity for a wet plate during the drying process (namely during the period of drop in the drying speed) under boundary conditions taking into account the conditions of drying is given. The calculation of the heat transfer coefficient is given, too. Based on the study of various sources and processing of experimental results, formulas for calculating the thermal conductivity coefficient of wet materials have been presented. The analytical solution of the problem confirmed that during convective drying in low-intensity processes of the second drying period, the temperature change with a decrease in moisture content turns from an exponential dependence smoothly into a linear one, which is completely consistent with the experiment. A comparison of the temperature calculation by the experimental formula with the results of analytical solutions has been presented. A sufficiently reliable coincidence of experimental and calculated analytical values of temperature for the period of drop in speed drying of ceramics, asbestos, and fabric is obtained.

The Effect of Chemical Composition on the Morphology of Pb/Zn-Containing Dust

Dust containing lead and zinc is a harmful contaminant, which causes serious harm to the natural environment and human health. At present, it is believed that the microscopic morphology of lead-zinc dust is intimately related to its biological toxicity. Chemical composition serves as a pivotal factor influencing the structural characteristics of dust. However, research on the impact of chemical composition variations on the microscopic morphology of dust containing lead and zinc remains inadequate. The particle size analysis reveals that as PbO content increases and ZnO content decreases, the particle size of the dust diminishes, but some samples exhibit a larger agglomeration structure. Combined with the results of the box number method, it is evident that at lower magnifications, an increase in PbO content leads to a decrease in image complexity and a loosening of aggregated structures. The similarity in pile shapes amplifies this trend, resulting in a decline in the box-counting dimension (D value) within the PbO/ZnO ratio range of 26.45 to 138, accompanied by an inverse change in the corresponding goodness of fit R-sq value. At the observation multiple of 30,000 times (30 K), smaller particles within the sample become visible, and the presence of relatively larger particles and complex sizes enhances the fractal characteristics of the sample, leading to a higher D value. Within the PbO/ZnO ratio range of 90/10 to 99/1, a coupling relationship exists between the chemical composition of the sample and the morphology of the dust. Specifically, the PbO/ZnO ratio exhibits a positive correlation with the D value. Conversely, the diversity of corresponding fractal features is negatively correlated with the D value. When the PbO content surpasses 99%, this correlation weakens, and the diversity of graphical representations displays an alternating pattern of growth and decrease. Notably, the D value and the goodness of fit (R-sq) of the D value are negatively correlated, indicating that as the complexity of the graph increases, the goodness of fit decreases.

Biofouling evolution driven by autoinducer-2 quorum sensing in reverse osmosis (RO) for water reclamation

Membrane biofouling remains a key challenge for reverse osmosis (RO) technology in water reclamation. This study investigated the biofouling development with time on RO membrane surface. During the biofouling evolution, the biofilm was examined through confocal laser scanning microscopy (CLSM) observation and foulant composition analysis. Results showed that organic/biofouling was the key contributor, and autoinducer-2 (AI-2), quorum sensing (QS) signaling molecules, were found to play an important role in coordinating community-level behaviors associated with RO membrane fouling. In the initial stage of fouling layer development, the attached cell and biopolymer contents increased with rising AI-2 activity. As development continued, the microbial community changed remarkably, exhibiting peak AI-2 activity as the membrane surface became fully covered with cells and the EPS matrix. However, in later stages, despite a decrease in AI-2 content and biological activity, the rate of increase in fouling resistance accelerated significantly due to continually accumulating foulants. As a result, the AI-2 QS was crucial during early phases of biofilm development in RO systems. This study helps to look deeply into the biological fundamentals of AI-2 mediated QS in RO fouling, enhancing the understanding of the mechanisms behind RO membrane fouling in water reclamation, and may facilitate the development of anti-fouling strategies.

Effects of ground motion characteristics on liquefaction response of earth dams using a non-Darcy hydro-mechanical model

During earthquake-induced excitations, significant pore pressure gradients can develop in earth dams, limiting the applicability of Darcy’s law for fluid flow. This study investigates the behavior of a liquefied earth dam subjected to various seismic excitations with differing frequency content, aiming to enhance insights into the effects of dynamic loading on fluid–structure interactions. To accurately capture the soil’s response, the Pastor-Zienkiewicz generalized plasticity model is employed to represent realistic soil behavior. Additionally, a modified Forchheimer equation is used to address varying permeability through a non-Darcy flow law. Numerical simulations, performed using a finite element code developed in Fortran, are validated through comparative analyses with previous studies. The results show that in low-permeability regions, changes in earthquake frequency content have minimal impact on discrepancies between the predicted results of Darcy and non-Darcy models. However, the non-Darcy model generally estimates horizontal displacements to be around 4% higher on average in these regions. This difference increases as earthquake frequency content decreases, reaching up to 6%. In contrast, in permeable regions, the non-Darcy model predicts significantly higher horizontal displacements, with an average increase of approximately 20% for high-frequency seismic events and 8% for low-frequency ones. Additionally, in high-permeability regions, the non-Darcy model deviates notably from the Darcy model as peak ground velocity increases, particularly affecting the upstream shell and clay core of the dam. This disparity becomes more pronounced as the input motion’s frequency content decreases, resulting in elevated pore pressures and slightly reduced vertical displacements in these regions.

Dynamic reaction of slag-based geopolymer with brick powder: insights from acoustic emission, heat flow, and relaxation characteristics

Fractal dimension, heat, and NMR relaxation characterizations were employed to monitor the dynamic geopolymerization process of slag-based geopolymer (SBG) with brick powder (BP) in this research. Introducing 30% BP to SBG resulted in a delay of 6minutes in the occurrence of polymerization peak, with a 24.12% decrease in heat peak value. Furthermore, during the rapid polymerization phase, the time of the gel formation in SBG containing 30% BP was reduced by 34.18%, accompanied by a 20.91% decrease in gel water content. The sequence of AE parameters associated with early-age geopolymerization reaction has good fractal characteristics, with fitting coefficient greater than 0.95. Importantly, the heat flow curve, water evolution, and corresponding fractal dimension curves have good correspondence at 0-3h. Especially, the dissolution peak and polymerization peak of the heat flow curve basically coincide with the fractal dimension curve. The fractal dimension not only serves as an effective indicator for evaluating the geopolymerization process but also compensates for the limitations of calorimetry in characterizing reaction processes with relatively small particle migration and local heat release.