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Whether the hydrate layer is stabilized during deepwater cementing operations has a direct impact on the safety of the cementing process and the quality of the cementing. When the cement slurry enters the annular space and waits for solidification, it will be extruded to produce filtrate under the action of formation temperature and pressure. Moreover, the inorganic ions and organic matter contained in the filtrate may penetrate into the formation. However, whether these processes have an effect on the stability of the hydrate layer is not clear at present. In this paper, we initially developed a methane hydrate generation system, termed the water-quartz sand-methane system. This system efficiently produces methane hydrate within a short time and ensures a uniform distribution of the gas-solid phase, which is highly suitable for further research into methane hydrate stability. Subsequently, the primary constituents of the cement slurry filtrate and the principal functional groups of the cement additive were identified. Furthermore, enhancements were made to the existing formula for quantifying methane gas alteration. Additionally, a hydrate testing experimental system was employed to circulate a solution comprising the primary constituents of the cement slurry filtrate over the methane hydrate surface. Ultimately, utilizing the amount of change in the volume of methane gas in the cyclic process as a criterion to evaluate the impact of various components of the cement slurry filtrate on methane hydrate stability, an investigation into the effect of the cement slurry filtrate on methane hydrate stability was conducted. It was confirmed that Ca2+, Na+, Cl− ions within the cement slurry filtrate, along with the pH value, minimally influence methane hydrate stability. Conversely, the cement additive exhibits a discernible disruptive effect on methane hydrate stability, with the retarder demonstrating the most pronounced impact when mass fractions are equated. This study suggests that the adverse effects of amide and carboxyl groups on hydrate stability must be considered in the selection of additives for deepwater cementing slurries. The findings offer guidance for the research and development of additives for deepwater cementing slurries and establish a theoretical foundation for studying cementing slurry systems in hydrate formations. • An improved formula for calculating methane gas changes in this experimental system is presented. • Effects of cement slurry filtrate pH and the inorganic ions it contains on methane hydrate stability are investigated. • Effect of cement additives on methane hydrate stability is investigated. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper investigates the applicability of time‐gated Raman spectroscopy (TRS) for online mineralogy identification, focusing on a Li‐bearing spodumene ore. The study provides an overview of existing online mineralogy tools and points out some limitations of elemental analysis techniques. Dense media separation concentrate and tailing samples used originated from a deposit in Quebec, Canada. Various techniques, including ICP‐AES, XRD, laser diffraction, and specific gravity determination, were used for detailed sample characterization. Samples and their mixtures at known ratios were prepared as powder and slurries, before being analyzed using TRS, followed by spectrum quantitative analysis. Results show a linear correlation between spodumene percentage by weight and the main Raman peak height or area, in both dry and slurry form, with a higher determination coefficient in slurry form. TRS also provided indications as to the gangue minerals present in the samples. This study shows the potential for TRS as a tool for online mineralogical assessment of spodumene ores, and further work should target the determination of detection limits and quantification of both valuable and gangue minerals. [ABSTRACT FROM AUTHOR]

Geopolymers represent a distinct class of materials characterised by their X-ray amorphous nature and nanoporous, nanoparticulate structure. Geopolymers can be conveniently mixed, poured, and cured under ambient conditions. This makes this class of materials an interesting alternative to ordinary Portland cement for structural processes. Additionally, the addition of alumina can improve mechanical properties, while the addition of glass can form an impermeable glaze which could be useful for molten salt containment. Therefore, in this investigation, potassium metakaolin-based geopolymer composites with varying proportions of glass particles and alumina platelets were fabricated, cured, heat-treated, and analyzed to study the effects of composition on material properties. Various attributes including rheological properties, densities, mass loss, shrinkage, and porosities were compared. It was observed that certain compositions exhibited high viscosities, making high shear mixing challenging, while also displaying significant permeability that would hinder their ability to contain liquids without leakage. Additionally, certain samples showed reduced densities, suggesting potentially weaker mechanical properties; however, the investigation did not include a direct assessment of mechanical properties. The most promising candidates for containing liquids at high temperature contained 50 wt% KGP, 25 or 35 wt% glass powder, and 25 or 15 wt% alumina platelets, respectively. ASH-G slurries required a minimum of 65 vol% KGP to produce a homogenous material compatible with additive manufacturing. The minimum amount of glass phase to form surface glazes was 16 vol%. Only samples containing more glass phase than alumina phase produced glazed composites. [ABSTRACT FROM AUTHOR]

Solid–state batteries based on Li7La3Zr2O12 (LLZO) garnet electrolyte are a robust and safe alternative to conventional lithium‐ion batteries. However, the large‐scale implementation of ceramic composite cathodes is still challenging due to a complex multistep manufacturing process. A new one‐step route for the direct synthesis of LLZO during the manufacturing of LLZO/LiCoO2 (LCO) composite cathodes based on cheap precursors and utilizing the industrially established tape casting process is presented. It is shown that Al, Ta:LLZO can be formed directly in the presence of LCO from metal oxide precursors (LiOH, La2O3, ZrO2, Al2O3, and Ta2O5) by heating to 1050 °C, eliminating the time‐ and energy‐consuming synthesis of preformed LLZO powders. In addition, performance‐optimized gradient microstructures can be produced by sequential casting of slurries with different compositions, resulting in dense and flat phase‐pure cathodes without unwanted ion interdiffusion or secondary phase formation. Freestanding cathodes with a thickness of 85 µm, a relative density of 95%, and an industrial relevant LCO loading of 15 mg show an initial capacity of 82 mAh g−1 (63% of the theoretical capacity of LCO) in a solid‐state cell with Li metal anodes, which is comparable to conventional LCO/LLZO cathodes and can be further improved in the future. [ABSTRACT FROM AUTHOR]

Grouting Fire Prevention technology is the most commonly used technology in coal mines. In order to improve the water holding capacity of the slurry and prevent the cracking and re-leakage of air caused by the loss of water, this paper used sodium alginate, sodium polyacrylate and gasification slag to prepare thick paste mixture, and then used calcium chloride to induce the gelation of the mixed paste surface to form an elastic solid film. A kind of environmental protection slurry of coated gasification slag (hereinafter referred to as coated slurry) with good environmental protection, high strength and elastic solid film with flame retardant and water retention on the outer surface was developed. In the 30°C-300°C range, when the coated slurry was heated, it would have a significant heat absorption and cooling effect. The results show that the hydrophilic -COO-, -OH in sodium alginate forms a synergistic effect with -COO-, -COOH in sodium polyacrylate, and enhances the water absorption of sodium polyacrylate; The interaction of calcium ions with sodium alginate on the surface of the mixed slurry causes gelation and forms a calcium alginate film on the surface of the coated slurry, which prevents water evaporation. [ABSTRACT FROM AUTHOR]

Different technologies can be utilised to mitigate environmentally harmful ammonia (NH 3) emissions after field application of liquid animal manure (slurry). After a solid-liquid separation, air-plasma technology can acidify the liquid fraction and enrich its nutrient value by increasing the amount of inorganic nitrogen. The present work investigates the emissions of NH 3 and volatile organic compounds (VOC) after field application of the following fractions of pig slurry and slurry digestate: i) untreated slurry (UN), ii) liquid fraction of slurry (LF), iii) liquid fraction of slurry treated with air from the plasma treatment (LP). Emissions were measured with a system of wind tunnels and a cavity ring-down spectrometer for NH 3 concentration measurements and a proton-transfer-reaction mass-spectrometer for measurements of VOC. For both slurry types, the cumulative NH 3 emissions were in the following order UN > LF > LP. All the differences were significant (P < 0.05), except between pig slurry LF and LP. The reduction in cumulative NH 3 emission obtained by the treatments compared to UN were 55–74% and 70–89% for LF and LP, respectively. The slurry separation decreased dry matter by 46–54% and resulted in a rapid decrease in slurry exposed surface area after application, presumably due to high infiltration. Several VOCs were measured after application of the slurry, but continuous emission was undetectable for all VOCs. The very low VOC emission was presumably due to high infiltration of the low dry matter slurry treatments and low concentration of VOC in the digestate. Science4Impact Statement • Separation with decanter centrifuge reduced slurry DM by 46–54%. • Treatment with plasma treated air lowered slurry pH by 1.6–1.8 units. • Separation of slurry decreased cumulative NH 3 emissions by 55–74%. • Separation + treatment with plasma treated air reduced NH 3 emission by 70–89%. • All slurry types investigated had low VOC fluxes after application. [ABSTRACT FROM AUTHOR]

This study developed three composite slurries for coating recycled aggregate by incorporating polyacrylate emulsion, fly ash, and gypsum into a cement-based mixture. The filling and pozzolanic effects of fly ash help to improve microcracks in the recycled aggregates. The polyacrylate emulsion forms a strong bonding layer between the cement matrix and the aggregates, enhancing the interfacial bond strength. Based on relevant studies, the following mix designs were developed: Slurry 1 consists of pure cement paste; Slurry 2 contains 15% fly ash and 3% gypsum added to the cement paste; Slurry 3 adds 22% polyacrylate emulsion to the slurry. The study first compared the effects of the three composite slurries on the crushing value and water absorption of recycled aggregates, and then analyzed their impact on the mechanical properties, permeability, and drying shrinkage of concrete. Finally, the mechanisms behind the enhancement were investigated using the Vickers Hardness Test (HV), Mercury Intrusion Porosimetry (MIP), and scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS). The results showed that the polyacrylate emulsion composite slurry had the most significant improvement effect. For recycled aggregate AL, the crushing value decreased from 28.8% to 22.5% and the saturated surface–dry water absorption decreased from 15.1% to 13.8% after cement slurry modification. After coating with the composite slurry, the crushing value further dropped to 18.2% and the water absorption to 9.5%. Two aspects of the performance of recycled aggregates are enhanced with the polymer composite slurry: first, fly ash provides nucleation sites for CH, reducing the tendency for directional CH alignment. Second, the long chains of PAE (polyacrylic ester) encapsulate cementitious particles, effectively filling surface defects on the recycled aggregates, improving the bonding strength at the new-to-old interface, and significantly enhancing the performance of both recycled aggregates and recycled concrete. [ABSTRACT FROM AUTHOR]

To clarify the deterioration behavior of magnesium oxychloride cement (MOC) under conditions of high humidity and high temperature, we first placed MOC slurry samples in a simulated environment with a relative humidity of 97 ± 1% and a temperature of 38 ± 2 °C; then, we observed the changes in the macroscopic and microscopic morphology, water erosion depth, bulk density, phase composition, and mechanical properties of the samples. The results show that, over time, under the promotion of high temperature, water molecules infiltrate the MOC samples. This results in the appearance of cracks on the macroscopic surface of the MOC samples due to the volume expansion caused by the hydrolysis of P5 (5Mg(OH)2·MgCl2·8H2O) and the hydration of unreacted active MgO in the samples. The microscopic morphology of the samples changes from needle/gel-like, to flake-like, and finally leaf-like. Simultaneously, the major phase composition turns into Mg(OH)2. Since the structure of the samples becomes looser and the content of the main strength phase decreases, the overall compressive strength and flexural strength are both reduced. The compressive strength of the MOC slurry samples (0 day) is 93.2 Mpa, and the flexural strength is 16.4 MPa. However, after 18 days of treatment, water molecules reach the center of the MOC samples, and the MOC samples completely lose their integrity. As a result, their compressive and flexural strengths cannot be obtained. [ABSTRACT FROM AUTHOR]

This study is dedicated to the development of a new type of cesium tungsten bronze energy-saving laminated glass and explores its application in insulating glass combinations, offering innovative ideas and practical solutions for advancing energy-saving glass technology. Experimental results show that both CsxWO3 (CWO) dispersions exhibit good visible light transmittance and near-infrared shielding properties, with CWO1 demonstrating superior shielding in the 650–950 nm range, attributed to differences in shape and size distribution and verified by simulations using the Drude–Lorentz model and the finite element method. [ABSTRACT FROM AUTHOR]

The pressure infiltration of fresh and salty bentonite slurries against a medium-fine sand has been investigated in a laboratory setup. In the tests, two series of salty bentonite slurries were used: non-pre-hydrated salty slurry, for exploring what will happen if directly salty water is used to make bentonite slurry, and pre-hydrated salty slurry, for identifying the consequence of pre-hydrated fresh bentonite slurry mixing with the salty water in the soil pores. The salty water employed was a mixture of different percentages of freshwater and seawater. Experimental results show that the test with non-pre-hydrated salty slurry exhibited a significantly faster and shorter (time) mud spurt, or even no mud spurt at all, compared to the test with fresh or pre-hydrated salty slurry. The influence of salty water on the pre-hydrated fresh bentonite is less than on the non-pre-hydrated slurry and depends on the seawater content in the salty water. Compared with the test with fresh bentonite slurry, a slower and shorter (time) mud spurt could be seen in the test with the pre-hydrated salty slurry when the seawater content was not more than 20%. As seawater content exceeded 20%, a faster mud spurt showed up; however, the timespan of the mud spurt may be shorter or longer, mainly depending on the viscosity and sedimentation behavior of the bentonite. A model to estimate the slurry infiltration distance during mud spurt is introduced, which agrees well with the experimental results using the measured input parameters. After the mud spurt, a filter cake would form in each test. The permeability of the filter cake increased with the increase in seawater content. Directly mixing salty water remarkably increased the permeability of the filter cake, while the pre-hydration of bentonite could reduce this increase. For instance, with the salty water containing 10% seawater, the permeabilities of the filter cakes formed by fresh bentonite slurry, non-pre-hydrated salty slurry, and pre-hydrated salty slurry with the 50 g/L bentonite concentration were 1.69 × 10−9 m/s, 2.26 × 10−8 m/s, and 3.23 × 10−9 m/s, respectively. [ABSTRACT FROM AUTHOR]

Flotation is a physical and chemical process that uses the difference between mineral surface properties to separate valuable minerals from worthless minerals through the attachment of bubbles. The visual information of the flotation foam surface can reflect the flotation effect and will be closely related to the flotation conditions, directly indicating the degree of mineralization of the foam layer. Considering the problem that coal slurry foam images are difficult to segment due to the mutual adhesion of bubbles and fuzzy boundaries, in this work, we proposed a new and effective segmentation algorithm for extracting coal slurry flotation foam edge information. Based on the encoder and decoder structure, a selective multi-branch input segmentation deep neural network model was designed. We evaluated the proposed method and model using a self-built coal slurry foam image segmentation dataset. The intersection over union, mean intersection over union, and PA evaluation indicators of this method increased by 12.8376%, 7.2716%, and 1.457%, respectively, compared with those of the U-Net model. The experimental results showed that the selective branch segmentation network model had high accuracy and robustness in extracting coal slurry bubble edge information, and it could effectively solve the problem of difficult segmentation of coal slurry foam images. This study provided a foundation for optimizing flotation process parameters and realizing intelligent flotation site parameters. [ABSTRACT FROM AUTHOR]

The forced oxidation of sulfite ions was conducted to obtain high-quality gypsum in the flue gas desulfurization system. The effects of formic, lactic, acrylic, acetic, propionic, and hexanoic acids added to calcium-based slurry on sulfite oxidation were investigated in this study. Sulfite oxidation was inhibited when the pKa value of organic acids was small or the carbon chain was long. In the identical slurry pH 6, the SO42- fractions of slurries with formic and lactic acids, which have the smallest pKa values, were lower than half that of the additive-free slurry. The addition of hexanoic acid with the longest carbon chain showed a similar SO42- fraction to that of additive-free slurry. These results indicate that the inhibitory effect on sulfite oxidation is more expressed by the acidity of organic acids. The SO42- fraction in the slurry affects the growth and quality of gypsum crystals. The slurry with acetic acid presented the highest SO42- fraction and resulted in the formation of high-quality gypsum crystals. The findings of this study can contribute to the selection of organic acid additives with high desulfurization efficiency and the production of high-quality gypsum. [ABSTRACT FROM AUTHOR]

In this work, magnesia‐alumina spinel foam ceramics were prepared by foaming‐sol method using magnesia alumina spinel as raw material, anionic surfactant potassium oleate (PO) as foaming agent, and alumina sol as curing agent. The curing mechanism and the effect of alumina sol content on the stability of foam slurry and the properties of foam ceramics were investigated. In the foam slurry, the alumina sol can react with PO, so magnesia‐alumina spinel can be fixed in the foam structure through the gel network to improve the stability of the foam slurry. The gelation process reduces the viscosity of the foam slurry. The pores of magnesia‐alumina spinel foam ceramics sintered at 1500°C are mostly closed pores and the average pore was 29.7–42.1 µm. With the increase of alumina sol content, the bulk density of magnesia‐alumina spinel foam ceramics increased from 1.3 to 1.9 g/cm3, the cold compressive strength from 8.8 to 22.7 MPa, and the thermal conductivity from.417 to.806 W·m−1·K−1(350°C). [ABSTRACT FROM AUTHOR]

Porous vitrified bond diamond grinding wheels are commonly used for grinding hard and brittle materials. However, uneven pore distribution and low porosity affect the grinding performance of the wheel significantly. In this study, three types of triply periodic minimal surface porous vitrified bond diamond grinding wheels—Gyroid, Diamond, and Lidinoid–were prepared through parametric designing and digital light processing 3D printing. The grinding wheel achieved a uniform distribution and an interconnected pore structure. The key to high-performance grinding wheel via stereolithography 3D printing lies in the preparation of the slurry with high solid loading, low viscosity and uniform stability. Hence, the effect of surface modifiers on the slurry, along with the effect of sintering temperature and the microscopic and mechanical properties, was investigated. By grinding the SiC ceramics, the material removal rate, grinding temperature, and surface roughness were compared to those achieved using a conventional solid-structure grinding wheel. The results show that the slurry with the highest solid content of 80 wt% (58 vol%) and viscosity of 4.21 Pa s (30 s−1) can be prepared using surface-modified particles. The diamond grinding wheel sintered at 680 °C exhibits the best comprehensive performance. A grinding wheel prepared using stereolithography 3D printing can achieve better surface roughness and lower the grinding temperature. [ABSTRACT FROM AUTHOR]

Porous β-Si 3 N 4 /Si 5 AlON 7 composite ceramics are anticipated to serve as high-temperature wave-transparent materials, yet the fabrication of high-performance porous β-Si 3 N 4 /Si 5 AlON 7 composite ceramics remains a significant challenge. Addressing this issue, this study introduces a technique for crafting high-performance porous β-Si 3 N 4 /Si 5 AlON 7 composite ceramics. This method involves the homogeneous blending of SiO 2 and Si 3 N 4 powders, followed by digital light processing and high-temperature liquid-phase sintering at 2000 °C. The impact of SiO 2 content on various properties of the ceramic slurry and the resultant ceramics was thoroughly examined, including rheology, curing depth, microstructural morphology, phase composition, flexural strength, hardness, dielectric constant, and dielectric loss. It was observed that a SiO 2 content of 30 % enables the slurry to fulfill the criteria for digital light processing, leading to the production of porous β-Si 3 N 4 /Si 5 AlON 7 composite ceramics that exhibit outstanding mechanical and dielectric properties. Specifically, these ceramics demonstrated a flexural strength of 149.2 ± 7.2 MPa and a hardness of 11.8 ± 1.1 GPa. Moreover, at a frequency of 10 GHz, the ceramics exhibited a dielectric constant of 4.02 and a dielectric loss of 0.11, highlighting their potential as high-temperature wave-transparent materials. [ABSTRACT FROM AUTHOR]

To solve the problem of the proportional design of cement concrete prepared by using manufactured sand instead of river sand, a new method of manufactured sand concrete mix design was proposed with the dense packing of coarse and fine aggregate. Compared with the original sieving method, the stone powder in the manufactured sand can be regarded as cementitious materials for slurry. With the proposed mix design method, there is no need to separate from the manufactured sand. This dense packing method considers the actual situation that both the manufactured sand and coarse aggregate are mechanically prepared, and all the aggregates can be unified in proportion. The composition ratio of aggregate with particle size greater than 0.075 mm is designed by the maximum density theory, and the rest of the part (below 0.075 mm) is treated as a cementitious material. As a parameter of the maximum density theory, the Fuller index of 0.45 was verified when the calculation values agreed well with the test results. With the proposed mix ratio design method, the different grades C30, C40, and C50 of manufactured sand concrete were designed. Furthermore, the properties such as workability and mechanical properties for the designed manufactured sand concrete were investigated to determine the applicability of the proposed mix design method. The test results show that the workability, uniformity, and strength of the manufactured sand concrete were better than the original mix ratio design method, which verifies the operability and reasonableness of the proposed mix ratio design method. [ABSTRACT FROM AUTHOR]

To address the engineering problem of wall collapse and destabilization during the construction of the slurry trench wall, the stability of the slurry trench wall under the condition of three-dimensional (3D) unsaturated stable seepage is studied using the upper limit analysis method and in combination with the three-dimensional rotating failure mechanism. The expression of the factor of safety (FS) for the unsaturated soil slurry trench was deduced by the gravity increase method. Additionally, a genetic algorithm was used to search for the minimum FS and the critical slip surface, and the obtained results were compared and validated with existing literature results. The effects of relevant parameters on the stability of the slurry trench under the condition of unsaturated seepage were analyzed in detail. The results of this paper indicated that ignoring the 3D effect of the slurry trench will underestimate the stability of the slurry trench. The presence of suction in unsaturated soil is beneficial to the stability of the slurry trench, and the impact of suction is closely associated with seepage conditions and the characteristics of the soil. The increase in surcharge load can lead to a decrease in the FS, and its effect on slurry trench stability increases with the enhancement of the three-dimensional effect. The impact of different seepage conditions on the sliding surface of the channel wall of clay strata is more significant, while the effect on the trench wall of sand strata is negligible. [ABSTRACT FROM AUTHOR]

The use of prefabricated horizontal drains (PHDs) combined with vacuum preloading (VP) has emerged as a popular dredged slurry treatment strategy. However, few theoretical contributions are available to assess its consolidation characteristics in practical engineering design and applications. In this context, an analytical model is proposed to predict the consolidation behavior of the dredged slurry with assistance of PHDs subjected to VP. Initially, an equivalent cylindrical unit cell is established in accordance with the area equivalence principle. Then the governing equation and analytical solution are derived by converting the external loading into the lateral loading acting on the typical unit cell. In the current model, the layered filling process of dredged slurry and the corresponding layered layout patterns of PHDs are comprehensively incorporated. Furthermore, an in-depth assessment is conducted to explore the impacts of several crucial parameters on the consolidation performance. Additionally, a laboratory model experiment is carried out to treat the dredged slurry by a double-layer crosswise layout of PHDs in combination of VP. Thereafter, the accuracy and reasonability of the obtained solution are validated through degradation analysis and experimental data. Based on the parametric analysis and experimental outcomes, compared with prefabricated vertical drains (PVDs), the use of PHDs is observed to facilitate the transmission of vacuum pressure and ensure a more uniform settlement of dredged slurry, thereby ultimately improving dewatering efficiency. [ABSTRACT FROM AUTHOR]

In this article, the review on different modeling approaches used for the dispersion of conductive slurries is presented. It comprises three parts: state‐of‐the‐art dispersion process, physiochemical properties, and different modelling approaches. The first part explains the physical mechanism involved in the mixing process and gives an in‐depth understanding of the applicability of the current techniques available commercially with respect to lab‐scale, pilot plant, and industrially upscaled production of these conductive slurries. The main challenges in slurry formulation prevent the formation of agglomerates and breaking down the preexisting agglomerates. It can be understood by studying the role of process parameters such as mixing time and stirring speed involved in the dispersion process. The second part focusses on the important physiochemical properties such as solid content, particle size distribution, and rheology that influences the electrode performance. The third part focusses on the available modelling approaches based on computational‐fluid‐dynamics‐ and coarse‐grained‐molecular‐dynamics‐based on the need as well as the complexity involved. The important aspects such as accuracy, computational cost, advantages, and limitations for both these approaches are discussed that will help the readers to select an appropriate technique in the modelling paradigm to reduce the energy consumption in the dispersion process. [ABSTRACT FROM AUTHOR]

Microalgae have emerged as a promising feedstock for biofuel production due to their ability to accumulate significant quantities of lipids. However, efficient extraction of these intracellular lipids remains a critical challenge. This study investigated pulsed electric field (PEF) and ultrasonic treatments for disrupting the robust cell walls of Nannochloropsis microalgae and extracting intracellular oils. A custom PEF setup with corrugated steel electrodes treated Nannochloropsis salina slurries under varying electric field strengths, pulse frequencies, processing times, and biomass concentrations. The Taguchi method optimized PEF parameters to maximize oil yields. Optimal PEF conditions of 20 kV/cm, 400 Hz, 30 min, and 20 g/L facilitated enhanced oil extraction by reversibly electroporating the cells. After PEF treatment, a solvent extraction process using chloroform and methanol recovered the released oils, yielding a maximum of 0.52 goil/gdry biomass while consuming 39.6 kJ/kg of energy. Notably, PEF outperformed ultrasonic treatment, achieving higher oil yields with minimal temperature rise that could degrade cellular components. Microscopic observations confirmed oil droplet release and cell membrane permeabilization after PEF, without significant cell debris. The results showcase PEF as an efficient, non-thermal, and environmentally friendly pretreatment approach for extracting oils from robust microalgae like Nannochloropsis, making it viable for microalgae-based biofuel and industrial applications involving oil extraction. [ABSTRACT FROM AUTHOR]

The combined effects of particle concentration (0–20 vol%) and particle size on the hydrodynamics of a slurry bubble column were studied by computational fluid dynamics coupled with population balance model (CFD‐PBM) in a wide range of superficial gas velocity (0.02–0.20 m/s). This CFD‐PBM coupled model included multiple effects of particles, namely increased slurry viscosity, reduced drag force, promoted bubble coalescence, and attenuated liquid turbulence, among which turbulence attenuation was crucial. To quantify liquid turbulence attenuation, a mechanistic model was established by equating the energy dissipated by particle motion to the attenuated liquid turbulence energy calculated from turbulent energy spectrum. The turbulent energy dissipation rate was reduced by over 60% at a solid concentration of 20%. Using this model, the effects of particle concentration and particle size on overall gas holdup were well predicted. This model advanced our understanding of how particles affect the gas holdup in a slurry bubble column. [ABSTRACT FROM AUTHOR]

The catalytic film of a flexible Al–air battery is generally a brittle film formed by brushing a slurry onto the surface of carbon cloth. Fatigue bending can easily lead to cracking of the catalytic film and shedding of the active material. This study innovatively proposes a novel grid‐structured catalytic layer prepared by electrohydrodynamic printing. Experiments have verified that, compared with traditional catalytic films, the grid‐structured catalytic layer exhibits excellent bending resistance. After 10 000 fatigue bending cycles, its relative resistance is ≈1/9 that of the traditional catalytic film. The printed grid‐structured catalytic layer is applied to a flexible Al–air battery, which maintains a power density retention rate as high as 92% after the same number of bending cycles. Compared to traditional catalytic films, the electrodynamically printed grid‐structured catalytic layer proposed in this study demonstrates both excellent electrochemical performance and bending resistance. This advancement holds significant importance for the development and application of flexible metal–air batteries. [ABSTRACT FROM AUTHOR]

In underground mine environments, factors such as low light intensity, diffusion of dust particles, and coal slurry coverage interfere with coal gangue identification. To further realize coal-gangue sorting underground, we analyzed the coal-gangue visual characteristics coupled with the above factors. The analysis reveals that both smoke environments and coal slurry coverage tend to make the coal-gangue visual features more consistent. There are still differences in coal-gangue visual features under smoke environments, while coal slurry coverage leads to gangue exhibiting coal-related feature information. To improve the detection capability of coal gangue in underground environments, this study adopts a coal gangue recognition method based on the DG module and YOLOX-PSB network: Utilize the DG module to achieve dehazing and then use the YOLOX-PSB model for object detection. The proposed method was validated through ablation experiments, and the results showed that the detection accuracy reached 99.6%, with an FPS of 98. The proposed method enables real-time detection and exhibits the best robustness in complex environments, realizing reliable and efficient performance. [ABSTRACT FROM AUTHOR]

Pig slurry can be used as an alternative source for nutrients, particularly nitrogen (N), for plants. However, after applying the pig slurry to the soil, gaseous loss of N this nutrient may occur, mainly in the form of ammonia. Hence this study aimed to evaluate the loss of N by volatilization after the application of pig slurry with an acidified pH. Ammonia volatilization was evaluated using pig slurry, with its pH modified to 5.0 using four acids (sulfuric acid, citric acid, ascorbic acid, and acetic acid). Additionally, pig slurry with natural pH and a control were also used. The work was conducted in a greenhouse, and collectors were used to capture the volatilized ammonia in a static free semi-open chamber. The application of pig slurry with natural pH (7.19) resulted in 61% loss of ammonia, whereas acidification with ascorbic acid (pH 5.0) caused a loss of only 26%. The application of pig slurry with pH above 7.0 caused N loss, indicating that using acids to maintain a pH of 5.0–6.0 could be an alternative to reduce N loss by ammonia volatilization. [ABSTRACT FROM AUTHOR]

Ice slurry is a phase-changing material composed of liquid water, ice crystals, and a freezing point depressant. It is finer and more uniform compared to ice cubes or flake ices and is used in many industries, such as food preservation, comfortable cooling, medical protective cooling, sport cooling, instrument cooling, firefighting, and artificial snowmaking, due to its high energy storage density. Ice slurry with high concentration can be used for cleaning equipment as its friction is several times greater than that of water at the same flow rate. This paper describes in detail the developments of ice slurry, including production methods, concentration measurement approaches, flow and heat transfer characteristics, as well as its applications in various industries. Problems to be solved or improved are also discussed, providing suggestions for better developments and applications in industrial environments. [ABSTRACT FROM AUTHOR]

Alumina toughened zirconia (ATZ) ceramics combine high biocompatibility with remarkable mechanical properties, making them suitable for dental and orthopedic implant applications. Producing these ATZ ceramics using slurry-based additive manufacturing necessitates homogeneous, stable suspensions with controlled particle sizes. Stabilizing such systems with the appropriate type and amount of dispersant is challenging, particularly since multi-component systems are prone to hetero-coagulation. In this study, ATZ powders with different surface areas were investigated to determine the optimum concentration of three commercially available dispersants: Darvan CN, Darvan 821 A, and Dolapix CE64, which have been successfully used to stabilize Al 2 O 3 and 3Y-TZP suspensions. Based on zeta potential (0.01 vol% suspensions), agglomerate size (0.01 vol% suspensions), sedimentation (10 vol% slurries), and rheological (40 vol% slurries) characterization, the optimum dispersant concentrations were found to be 0.50 mg/m2 for Dolapix CE64, 0.75 mg/m2 for Darvan 821 A, and 1.50 mg/m2 for Darvan CN. Among the studied dispersants, Dolapix CE64 was the most effective in terms of reduced sedimentation, smaller agglomerate size (0.70 μm), flow behavior, and low resistance to structure breakdown. The rheological assessment showed that slurries prepared with ATZ powder featuring a smaller specific surface area (7.3 m2/g) resulted in lower viscosity, critical stress, and equilibrium storage and loss moduli compared to those prepared with higher specific surface area (13.3 m2/g) starting powder. The sedimentation analysis however revealed that the larger specific surface area ATZ powder exhibited higher slurry stability. While 38 vol% ATZ pastes without dispersant showed inhomogeneous extrusion and the presence of aggregates, the filaments extruded from 45 vol% paste with 0.50 mg/m2 Dolapix CE64 had a homogeneous and smooth structure and were free of aggregates, highlighting the importance of the dispersant addition for DIW. [ABSTRACT FROM AUTHOR]

Grouting is a widely used geotechnical procedure known for its strong empirical properties. It has been extensively utilized for sealing subterranean water and strengthening soil and rock masses in their original locations in underground mining and underground space development. The diffusion mechanism of grouting in fractured rock is affected by the geological environment and slurry performance, which should be better revealed and characterized. In this paper, we take the surrounding rock of the roadway as the research object, consider the stress condition of the injected rock and time-dependent viscosity of the slurry, and establish fracture grouting diffusion model based on the rock composite fracture criterion. The grout strengthening mechanism is discussed based on a transparent fracture replica grouting test. According to the different transport characteristics of the slurry interacting with flowing water, it is divided into the following four areas grout-water balance area, grout loss area, stagnation area and water passage. The grout plugging mode is divided into two categories according to its final diffusion pattern: cross-section type water plugging mode and water-drop plugging mode. The pressure monitoring data of the test verified the two grout plugging modes. The diffusion distance of cis-reverse water derived in this study was in good agreement with the experimental results in grouting early stage. The research results can provide a theoretical basis for grouting engineering design. • Fracture grouting diffusion model based on the rock composite fracture criterion. • The grout strengthening mechanism is discussed based on a transparent fracture replica grouting test. • Slurry travel is divided into the following four areas, grout-water balance area, grout loss area, stagnation area and water passage. • The grout plugging mode is divided into two categories according to its final diffusion pattern. [ABSTRACT FROM AUTHOR]

A digital process was developed to facilitate additive manufacturing for ceramic materials using digital light processing (DLP). A numerical model that predicts DLP sample properties can be generated from manufacturing inputs to forecast the effect of resin age on mechanical strength of the printed part based on data collected from experiments. Key parameters for printing the green bodies included determining the depth of cure, layer thickness, material composition, and solids loading. Thermogravimetric analyses were used to develop debinding and sintering curves. Debinding is used to remove the volatile organics comprising the photopolymer resin. Sintering is performed after debinding to increase density and mechanical strength of the printed parts. The sintered parts were then subjected to characterization and mechanical testing. The ensemble of data for various DLP-printed ceramic materials were added to a database. A design of experiments can be generated from the manufacturing process defined in the database with selected changeable parameters randomized over a range. Because the database is defined with an architecture to capture manufacturing processes, it can persist as a more generic platform for manufacturing digital twins. This can ease the development of future digital twins and can grow as a common repository for the insights gained from manufacturing research. Creating a digital twin of a DLP system for 3D printing parts enables manufacturers to simulate and assess the impact of resin age on printing parameters and part quality, facilitating optimization, predictive maintenance, and cost reduction. [ABSTRACT FROM AUTHOR]

A 2.8 MM TPY heavy oil catalytic cracking unit in a refinery has been undergoing slurry recycling for about six months under low processing capacity. The recycling method involves injecting the recycled slurry into the mixed feedstock oil at the feedstock self-protection assembly and then into the feedstock oil nozzle. After calibration, the yield of coke increases from 7.86% to 8.41%, accounting for about 20% of the recycled slurry to produce coke. The diesel yield of the unit has increased, and about 50% of the recycled slurry has been converted or becomes high-value diesel products. The slurry recycling resulted in a decrease in the overall conversion rate of the unit, with a total reduction of 1.93 percentage points in the yields of dry gas, liquefied petroleum gas, and gasoline. During the recycling process of slurry, the unit monitors the feedstock oil and reaction system, and has not found any significant impact on coking in the reaction system, wear of the feedstock oil pipeline and nozzle, or other defects. Subsequent defect elimination inspections have also not found any abnormalities. Overall, the recycling of slurry increases the coke yield of the unit, ensures steam balance in the entire plant under low processing capacity, and effectively reduces the solid content of slurry, resulting in a decrease in the yield of slurry in the unit. [ABSTRACT FROM AUTHOR]

Generally, 100% vacuum residue is not processed in fixed-bed residue hydrogenation units, and the proportion of vacuum residue in feedstock is not higher than 65% . The A fixed bed residue hydrogenation unit has six cycles, and the operating results show that the higher the proportion of vacuum residue in feedstock, the shorter the operating cycle of the unit. The volume space velocity of the B fixed bed residue hydrogenation unit is 0.20 h-1. If the volume space velocity decreases to 0.15 h-1 and 0.10 h-1, the reactor pressure drop is expected to increase to 2.3 MPa and 3.4 MPa, respectively. The yield of hydrogenated heavy oil in the A fixed bed residue hydrogenation unit is as high as 93.25%, and the conversion rate of fractions above 520 °C is only 25.38%. Ebullated bed residue hydrocracking technology and slurry bed residue hydrocracking technology can process vacuum residue. The pressure drop in the reactors of the ebullated bed unit C and the slurry bed unit D is stable, with a pressure drop of only 0.42 MPa in reactor of unit D. The conversion rates of typical ebullated bed residue hydrocracking technology and slurry bed residue hydrocracking technology can reach 85.87% and 91.49%, respectively. [ABSTRACT FROM AUTHOR]

When wet soil becomes fully saturated by intense rainfall, or is shaken by an earthquake, it may fluidize catastrophically. Sand-rich slurries are treated as granular suspensions, where the failure is related to an unjamming transition, and friction is controlled by particle concentration and pore pressure. Mud flows are modeled as gels, where yielding and shear-thinning behaviors arise from inter-particle attraction and clustering. Here we show that the full range of complex flow behaviors previously reported for natural debris flows can be reproduced with three ingredients: water, silica sand, and kaolin clay. Going from sand-rich to clay-rich suspensions, we observe continuous transition from brittle (Coulomb-like) to ductile (plastic) yielding. We propose a general constitutive relation for soil suspensions, with a particle rearrangement time that is controlled by yield stress and jamming distance. Our experimental results are supported by models for amorphous solids, suggesting that the paradigm of non-equilibrium phase transitions can help us understand and predict the complex behaviors of Soft Earth suspensions. Regarding the failure and flow of wet soil, a question that remains is how soil material composition influences rheology. Based on Soft Earth suspension flow experiments, the authors discover a continuous transition from frictional-to-cohesive rheology recreating all complex behaviors reported for natural soil slurries. [ABSTRACT FROM AUTHOR]

The paper presents experimental findings on the atomization characteristics of coal–water slurries with and without petrochemicals. The fuels were based on flame coal filter cake (slime), which is a typical coal processing waste, flame coal of different particle sizes, wood biomass (sawdust), used transformer oil, and water. The atomized flow characteristics—droplet size and velocity as well as jet angle—were found to depend on the atomizer dimensions and slurry rheology. The experimental data were used to calculate the slurry atomization efficiency factor. The findings were generalized to provide a mathematical description of how the slurry composition and atomizer geometry affect the slurry atomization behavior. Approximations were obtained for atomization characteristics that can be used to predict the jet angle as well as droplet radii and velocities. The developed mathematical tool can be employed to calculate the spraying characteristics when using devices like external-mix twin-fluid atomizers. The approach proposed for data generalization can be applied to adapt the set of approximation equations to other types of nozzles. [ABSTRACT FROM AUTHOR]

This research investigates the infiltration patterns of a bentonite-sand slurry into saturated sand. Bentonite-sand slurry is formed when excavated sand mixes with bentonite slurry inside the excavation chamber, a common phenomenon during slurry shield tunneling. Employing a normal laboratory setup designed to emulate field conditions, the study elucidates the impacts of varying bentonite and sand concentrations, as well as the pressure applied, on the infiltration process. The findings highlight that low-permeability zone invariably form on the sand layer's surface, with their formation rate and pressure transfer efficiency being negatively influenced by the sand particle accumulation from the slurry. The infiltration process, as dictated by changes in the Peclet number (Pe), can be effectively categorized into three distinct stages: mud spurt, internal filter cake formation, and surface filtration. The correlation between the duration of the first two stages and the sand content can be described by a linear function. It was observed that low-permeability zone formation can be expedited, and slurry pressure transfer can be enhanced, by increasing the concentration of bentonite. The manipulation of excess slurry pressure, however, produced inconsistent outcomes, as increased applied pressure was found to lower pressure transmission efficiency. Mechanisms of bentonite-sand-slurry infiltration are discussed, and implications for field applications are described. [ABSTRACT FROM AUTHOR]

To determine the stability and hardening strength characteristics of waste rock-ungraded tailings slurry in a gold mine, tests were conducted on the slurry-s bleeding rate, stratification degree, and hardening strength. The stability of the filling slurry was evaluated using the bleeding rate and stratification degree as indicators. An in-depth analysis was performed on the uniaxial stress-strain curve, failure behavior, factors influencing the strength, and the evolution of the filling bodys strength. Based on the test data, a regression model for the strength of the filling body was established and verified through supplementary tests. The test results showed that when the concentration is below 68 %, the proportion of waste rock has a dominant effect on the stratification degree. When the concentration exceeds 68 %, the influence of waste rock addition on slurry segregation decreases, while changes in the cement-sand ratio lead to reduced anti-segregation performance. Under conditions of a high cement-sand ratio, increasing the proportion of waste rock reduces the elastic strain value, whereas the plasticity of the filling body decreases as the waste rock proportion increases. The main strength increase of the filling body occurs within the first 0-7 d of curing, after which the rate of strength growth gradually slows. Factors influencing the rate of strength growth are cement-sand ratio>slurry concentration. The established regression model for predicting the filling slurry mix parameters shows an error margin within ±15 %, making the model reliable for providing a reference for future mix optimization. [ABSTRACT FROM AUTHOR]

The coupling effect between the spatial variability of slurry diffusion and the time-varying viscosity of quick-setting slurry is the time–space characteristics of slurry viscosity (TSCSV). The TSCSV is the governing factor for the complex and uncontrollable flow of slurry in fractures. In this regard, the flow pattern of quick-setting slurry is considered as a Bingham fluid with viscosity spatiotemporal characteristics. Using the fractal function with random parameters (W-M function), a single fracture with random fracture opening (RFO) is drawn, and a theoretical model on grouting diffusion in fractures is established considering the TSCSV. The RFO is corrected for head loss, and the spatiotemporal distribution equation of the RFO grouting pressure is derived. The relationship between grouting pressure, grouting time, and slurry diffusion distance is obtained. Additionally, the effects of the RFO, the fractal dimension of the fracture curve, the horizontal movement distance of the lower end face of the fracture, and the effects of viscosity and grouting rate on the viscosity and grouting pressure in the slurry diffusion space are discussed. Finally, by predefining the spatial distribution function of slurry viscosity for a single fracture in the numerical calculation model, a numerical simulation of random fracture distribution grouting considering viscosity spatiotemporal characteristics is achieved. The rationality of the model is validated through a comparison of theoretical analysis and numerical simulation, providing reference for the determination of grouting parameters in practical grouting projects. [ABSTRACT FROM AUTHOR]

Quality control in a production plant shows its maximum potential in the form of inline measurements. Defects and imperfections can be detected early and directly, and waste and costs can be reduced. Nuclear Magnetic Resonance offers a wide range of applications but requires dedicated adaptation to the respective process and material conditions. A V-shaped low-field NMR sensor was developed for non-invasive inline measurements on anode slurries in a battery production plant. In battery production, inline monitoring of the quality of anode slurries is demanded, offering the possibility of predictive control of the following process steps. Methods of low-field NMR to determine flow properties were adapted to the desired application. Further, magnetic resonance imaging measurements were made to determine the flow properties of model substances and anode slurries, thus providing verification. The sensor measurements show the ability to measure the flow behavior of, amongst other fluids, anode slurries in a form suitable for inline quality control in a battery production plant. [ABSTRACT FROM AUTHOR]

A lanthanum–cerium-based abrasive composed of CeO2, LaOF, and LaF3 was commercially obtained. The effect of sodium hexametaphosphate (SHMP) on powder dispersion behavior was systematically investigated using the combined techniques of liquid contact angle, turbidity, zeta potential (ZP), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) combined with Rietveld refinements, X-ray photoelectron spectroscopy (XPS), and polishing tests. The results indicated that the addition of 0.5 wt.% SHMP dispersant to the 5 wt.% lanthanum–cerium-based slurry produced the most stable suspension with a high turbidity of 2715 NTU and a low wetting angle of 45°. The as-obtained slurry displayed good surface polishing quality for K9 glass, with low surface roughness (Ra) of 0.642 and 0.515 nm (in the range of 979 × 979 μm2) at pH = 6 and 11, respectively, which corresponds to the fact that it has local maximum absolute values of ZP at these two pH values. SEM images demonstrated that after appropriate grafting of SHMP, the particle aggregation was reduced and the slurry's dispersion stability was improved. In addition, the dispersion mechanism was explained based on the principle of complexation reaction, which reveals that the dispersant SHMP can increase the interparticle steric hindrance and electrostatic repulsions. In an acidic environment, steric hindrance dominates, while electrostatic repulsion prevails under alkaline conditions. As expected, this polishing slurry may find potential applications in manufacturing optical devices and integrated circuits. [ABSTRACT FROM AUTHOR]

Synchronous grouting technology is a crucial aspect of shield tunnel construction. However, understanding the mechanism of slurry diffusion during this process is challenging due to its complexity and invisibility. Existing theoretical models often oversimplify the grouting process and do not account for multi‐stage diffusion mechanisms. By considering the radial penetration of slurry and viewing the diffusion process as the formation of annular pancakes through circumferential filling, a 3D diffusion numerical model is established using the volume of fluid (VOF)‐multiphase flow model in Fluent software. The model's validity is confirmed through calculations based on theoretical formulas and monitoring data from engineering examples. This study uncovers the patterns of slurry diffusion and examines how factors like porosity, grouting pressure, and slurry density impact diffusion radius and segment stress. The findings of this research provide a crucial theoretical foundation for shield synchronous grouting construction. [ABSTRACT FROM AUTHOR]

Porous Si3N4 ceramics were prepared using the low‐toxicity monomer HEMA (2‐hydroxyethyl methacrylate) via a modified gel casting method. The rheological properties of Si3N4 slurries were investigated. Triethanolamine with high activity was used as a catalyst and modifier for gelation reactions, effectively improving the curing rate and suppressing the inherent surface oxygen inhibition in such process systems. With an increase in solid loading of the slurry, the drying shrinkage (12.3% to 5.4%) significantly decreased, while the green body density (44.0%–49.0%) and flexural strength (9.65–16.46 MPa) increased, demonstrating an excellent mechanical strength. After sintering at 1700°C, the porous Si3N4 ceramics prepared with 24–36 vol% solid loading slurry exhibited a flexural strength of 144.39–193.66 MPa and a porosity of 55.8% to 49.0%. The dielectric constant and loss tangent at 30 GHz ranged from 2.88 to 3.38 and 1.17–1.56 × 10−3, respectively. These ceramics show promising potential applications in high‐performance structural ceramics and high‐temperature wave‐transparent materials. [ABSTRACT FROM AUTHOR]

During the underground excavation, various flaws are frequently observed, which significantly decrease the mechanical properties of surrounding rock, as has been proven. As known, grouting technology is a means of reinforcement that efficiently enhances the stability of underground engineering. However, existing studies have mainly focused on increasing the strength of the slurry stone, and relatively less attention has been paid to the poor bonding effect at the interface between the slurry and the rock mass. In this work, we proposed to adopt slurry containing nano-silica sol to reinforce the fractured rock mass. Based on the mechanical model of micro–nano-siliceous slurry reinforcement for single fractured rock masses established in this paper, the effect and the mechanism of micro–nano-siliceous slurry reinforcement for fractured rock were explored through theoretical analysis, laboratory tests, and numerical simulations. Results showed that the application of micro–nano-siliceous slurry increased the friction and the bonding force at the slurry–rock interface, which led to a (σn·Δμ + Δc) reduction of the effective stress. The optimum incorporation rate of the nano-silica sol was determined to be 3% based on these indicators including slurry fluidity, slurry stone rate, and strength and deformation parameters of slurry stone. The peak strength of the sandstone specimens reinforced by the micro–nano-siliceous slurry increased by 16.49% those of the sandstones reinforced by the ordinary slurry, and the elastic energy accumulated by the former was higher. Scanning electron microscope images revealed that the incorporation of nano-silica sol distinctly improved the pore characteristics of the slurry-rock interface. Finally, on the basis of 1790 ventilation roadway of Shiyakou coal mine, the effectiveness and the feasibility of micro–nano-siliceous slurry for reinforcing underground engineering surrounding rocks were verified using numerical simulation. Highlights: This paper developed a new micro–nano-siliceous grouting material. A mechanical model for fractured rock mass reinforced by new slurry was proposed. The optimal incorporation rate of nano-silica sol was determined by various means. This study demonstrated the effectiveness of the new grouting material in reinforcing fractured rock mass by control lab experiments and numerical simulation. The mechanisms of micro–nano-siliceous slurry to improve slurry–rock interface were revealed. [ABSTRACT FROM AUTHOR]

• S-NZVI/rGO@GG slurry showed excellent stability and mobility performance. • Higher GG concentration, pH, and low ionic strength are beneficial to improve the transportability of S-NZVI/rGO@GG slurry. • Brownian action dominates S-NZVI/rGO@GG slurry deposition in saturated porous media. • CFT, XDLVO, and kinetic fitting were combined to explain attenuated Brownian motion and GG spatial repulsion play a key role in migration. Nanoscale zero-valent iron (NZVI), which has the advantages of small particle size, large specific surface area, and high reactivity, is often injected into contaminated aquifers in the form of slurry. However, the prone to passivation and agglomeration as well as poor stability and mobility of NZVI limit the further application of this technology in fields. Therefore, sulfided NZVI loaded on reduced graphene oxide (S-NZVI/rGO) and guar gum (GG) with shear-thinning properties as stabilizers were used to synthesize S-NZVI/rGO@GG slurries. SEM, TEM, and FT-IR confirmed that the dispersion and anti-passivation of NZVI were optimized in the coupled system. The stability and mobility of the slurry were improved by increasing the GG concentration, enhancing the pH, and decreasing the ionic strength and the presence of Ca2+ ions, respectively. A modified advection-dispersion equation (ADE) was used to simulate the transport experiments considering the strain and physicochemical deposition/release. Meanwhile, colloidal filtration theory (CFT) demonstrated that Brownian motion plays a dominant role in the migration of S-NZVI/rGO@GG slurry, and the maximum migration distance can be increased by appropriately increasing the injection rate. Extended-Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory showed that the excellent stability and migration of S-NZVI/rGO@GG slurry mainly came from the GG spatial forces. This study has important implications for the field injection of S-NZVI/rGO@GG slurry. According to the injection parameters, the injection range of S-NZVI/rGO@GG slurry is effectively controlled, which lays the foundation for the promotion of application in actual fields. [Display omitted] [ABSTRACT FROM AUTHOR]

Utilizing recycled concrete aggregate (RCA) is a countermeasure to address the scarcity of landfills and the depletion of natural aggregates. Surface modification techniques have been proposed and implemented to improve the properties of RCA; however, to our best knowledge, few investigations on improving RCA under various pozzolanic slurry concentrations and extended soaking durations have been done. This study comprehensively assessed the properties and microstructure of low-strength RCA treated with cement–fly ash slurry with different concentrations and soaking durations. The purposes of this study were not only to provide the optimal slurry concentration and treatment duration but also to explore the enhancement mechanism of RCA under various treatment conditions. The RCA from concrete with a low-strength grade of 20 MPa was soaked in cement–fly ash slurry at low and high concentrations (i.e., 30% and 70% by mass of RCA, respectively) for 24 and 72 h. The physical and mechanical properties of RCA before and after treatment were evaluated through water absorption and crushing value measurements, respectively. Additionally, the pore structure, Ca(OH)2 contents, surface morphology, and phase compositions of RCAs were evaluated through a mercury intrusion porosimetry test, thermal gravimetric differential thermal analysis (TG-DTA), scanning electron microscopy, and X-ray diffraction (XRD) analyses, respectively. The water absorption of treated RCA reduced by 9.2%–37.9%, whereas the crushing value decreased by 8.6%–26.9% compared with the untreated RCA. The TG-DTA results indicated a 22.3%–43.8% increase in the Ca(OH)2 content of treated RCA. The XRD analysis depicted a higher ettringite (AFt) peak in all treated RCA samples compared with the untreated sample. For both concentrations, with a 24 h treatment, the slurry infiltration effect was clearly observable, whereas the 72 h treatment resulted in the formation of a pozzolanic coating layer on the RCA surface. In conclusion, the optimal slurry concentration and soaking duration were 70% and 72 h, respectively. [ABSTRACT FROM AUTHOR]

This study aims to clarify the mechanism of slurry support and its effect at different stages of slurry infiltration in shield construction. The analysis of various expressions of slurry support throughout the entire excavation cycle is based on the theories of slurry infiltration effects and the cutting action of the cutters. Furthermore, the limit support pressure calculation method at the tunnel face is modified considering the slurry support mechanism observed during different slurry infiltration stages. Some of the main conclusions drawn are as follows. (1) When slurry deep infiltration occurs, the main form of slurry support is the seepage force acting on the soil skeleton. At this stage, the limit support pressure from the filter cake model will not be sufficient to meet the tunnel face stability requirements. (2) The effectiveness of slurry support is influenced by both the slurry infiltration state and the cutting action of the cutterhead. Slurry infiltration and shield tunneling together create a quasi-static equilibrium state, in which slurry support is effective only when the infiltration velocity corresponding to this state is greater than the critical velocity. (3) And the influence of shield tunneling parameters on the slurry support mechanism is significant. Compared with the cutter's penetration degree, the cutter's rotational speed has a more pronounced effect on the conversion rate of slurry support pressure at the shield tunnel face. [ABSTRACT FROM AUTHOR]

High-strength alumina (Al2O3 ) was utilized as a reinforcing phase to improve the strength of hydroxyapatite (HA), a bioactive material, but the HA-Al2O3 ceramics prepared by traditional hydrothermal method could not achieve the precise control of pore size and porosity, whereas the light curing additive manufacturing technology could achieve the high precision molding of HA-Al2O3 ceramics through the high-performance photocurable slurry. The state of HA-Al2O3 slurry is adjusted by the addition of dispersant, photoinitiator, and photoabsorbent to alleviate the severe scattering effect caused by the refractive index mismatch between HA powder, Al2O3 powder, and photosensitive resin. In this study, the effects of the type and content of photoinitiator and dispersant on the slurry were explored. The rheological and curing properties of the slurry are first improved and then weakened with the addition of both, and the optimal dosages of photoinitiator and dispersant are 0. 5% and 4% (mass fraction), respectively. The effects of two light absorbers, graphite and methyl yellow, on improving the printing accuracy were compared. Although graphite improves the printing accuracy and rheology of the slurry, it reduces the printing quality, so the dosage of 5.0 x 10-5 methyl yellow is determined, and finally HA-Al2O3 slurries suitable for high precision printing are obtained. [ABSTRACT FROM AUTHOR]

Coal is often adhered to by pyrite during slime flotation, causing an increase in the sulfur content of clean coal. In order to study the mechanism of pyrite adhesion to coal surfaces, different coal structural units were built and optimized, and the most stable adsorption model of them on pyrite surfaces was determined. The mechanism of pyrite particles adhering to the surface of coal slurries was explored with the method of DFT. The results showed that the interaction mechanism between pyrite surface and Ph-OH and Ph-O-CH3 was the result of a weak interaction between the H atom of Ph-OH and Ph-O-CH3 and the S atom of the pyrite surface. The interaction mechanism between the pyrite surface and Ph-COOH and Ph-CO-CH3 was both as a result of H-S interactions and weak Fe-O interactions. On the whole, there were weak interactions between pyrite particles and the coal slurry, and the pyrite particles can spontaneously adsorb on the surface of the coal slurry. [ABSTRACT FROM AUTHOR]

In district cooling systems, substituting the conventional cooling medium with ice slurry represents an ideal approach to achieve economical operation. During pipeline transportation, ice slurry exhibits heterogeneous flow characteristics distinct from those of pure fluids. Consequently, investigating the flow field characteristics of non-homogeneous ice slurry, quantitatively analyzing the rheological variations and flow resistance laws due to the uneven distribution of ice particles, and standardizing the comprehension and depiction of flow patterns within ice slurry pipes hold significant theoretical importance and practical value. This study analyzes the heterogeneous isothermal flow characteristics of ice slurry in a straight pipe by employing particle dynamics and the Euler–Euler dual-fluid model. Taking into account the impact of ice particles' non-uniform distribution on the rheological properties of ice slurry, a particle concentration diffusion equation is incorporated to develop an isothermal flow resistance model for ice slurry. The flow behavior of ice slurry with initial average ice particle fractions (IPFs) ranging from 0% to 20% in DN20 horizontal straight and elbow pipes is examined. The findings reveal that the degree of heterogeneous flow in ice slurry is inversely proportional to the initial velocity and directly proportional to the initial concentration of ice particles. When the flow velocity is close to 0.5 m/s, the flow resistance of ice particles exhibits a linear positive correlation with changes in flow velocity, whereas the flow resistance of the fluid-carrying phase displays a linear negative correlation. As the flow rate increases to 1 m/s, the contribution of each phase to the total flow resistance becomes independent of the initial velocity parameter. Additionally, the drag fraction of the ice particle phase is positively associated with the initial concentration of ice particles. Furthermore, the phenomenon of "secondary flow" arises when ice slurry flows through an elbow, enhancing the mixing of ice particles with the carrier fluid. The extent of this mixing intensifies with a decrease in the turning radius and an increase in the initial velocity. [ABSTRACT FROM AUTHOR]

A new method is presented for the simultaneous determination of 13 multiclass pesticides along with glyphosate. The multiclass pesticides were extracted by creating a soil slurry with 2% ethanol in water (v/v), and then, applying direct-immersion solid-phase microextraction (DI-SPME) with a new type of semi-disposable SPME fiber configuration called LC-Tips. The fibers were then retroextracted to ethanol, and aqueous ammonia was added to the slurry to extract glyphosate. Derivatization of the glyphosate extract was accomplished with a mixture of trifluoroacetic anhydride and trifluoroethanol, after which the reaction mixture was dried and resuspended with the SPME ethanol extract. To this, a mixture of analyte protectants was added, and it was analyzed by GC-MS/MS in multiple-reaction-monitoring mode. All analytes showed a coefficient of determination greater than 0.95 in the 0.1–100 µg/kg calibrated range, and the limits of detection were between 0.1 and 1 µg/kg, except for glyphosate, which was 0.01 µg/kg. The method shows relatively high replicate relative standard deviation (as much as 37% for five extractions at 20 µg/kg), but the isotopically labeled internal standard was effective at mitigating this effect for some analytes. [ABSTRACT FROM AUTHOR]

The present study speaks of development of a two-dimensional phase field (PF) model to simulate the cooling slope rheoprocessing of the novel Al-15Mg2Si-4.5Si composite, in view of process optimization and investigation of physics of microstructure formation. In case of cooling slope rheoprocessing, the composite melt starts losing its superheat once it impinges over the slope and transforms into semi-solid slurry during its length of travel over the slope. After experiencing shear flow over the slope, the melt fills an isothermal slurry holding furnace where it undergoes coarsening for a certain length of time. The present PF model simulates how heterogeneous nucleation of solid grains is supposed to happen within the melt, during cooling slope processing, adopting a seed undercooling-based nucleation model. Moreover, the PF model implements a grain coarsening model to simulate the isothermal globularization process of the evolving solid grains of primary Mg2Si and primary Al phases. The interfacial free energy of Al–melt interface is taken from literature, whereas a molecular dynamics (MD) model is employed to estimate the interfacial energy value of the Mg2Si–melt interface. The cooling rate values employed in the present PF model for different melt pouring temperatures are determined experimentally from initial trial experiments, whereas the validation experiments are performed to collect the slurry samples from chosen locations of the melt flow front over the slope and from isothermally kept slurry holding furnace. Micrographs obtained from the above samples confirm the accuracy of the developed 2D PF model to capture microstructural morphology of the composite slurry. Moreover, the model predictions of quantitative parameters such as grain diameter, shape factor/sphericity, and solid fraction are found to be close to the experimental measurements. For example, a representative simulated value of grain size and sphericity of primary Mg2Si grains, after 8 minutes of slurry holding, are as follows: 24.01 and 0.834 μm, whereas the corresponding experimental values are 29.0 and 0.885 μm, respectively. [ABSTRACT FROM AUTHOR]

When an earth pressure balance shield passes through soft-upper and hard-lower composite strata, it faces challenges such as cutterhead "mud cake" formation, inefficient muck removal, and tool wear. To address these issues, this study focused on silty clay-completely weathered granite composite strata and conducted laboratory tests on ground conditioning in different strata based on the adaptability and performance of soil conditioners. The study explored the effects of soil conditioners, such as foam agent and bentonite slurry, as well as their improvement methods on soft-upper and hard-lower strata, to determine an optimal ground conditioning scheme and the appropriate addition ratios for shield tunneling in composite strata. The results showed that: (1)Combining a 3% concentration foam agent solution with bentonite slurry at a 1 : 8 ratio yielded good results. (2)The silty clay strata were improved by foam agent. The slump of the muck increased with the foam addition ratio, while the shear strength, cohesion, internal friction angle, and permeability coefficient decreased. The optimal addition ratio of the soil conditioners was between 19. 7% and 22. 8%. ( 3) The completely weathered granite strata were improved using a combination of foam agent and bentonite slurry, which effectively enhanced the flow plasticity and impermeability of the muck. When using only foam, the optimal addition ratio was between 22. 2% and 28. 7%, while the combined foam and bentonite slurry method required a ratio of 24. 3% to 31. 5%. Field application and construction feedback showed that the above improvement scheme effectively enhanced the flow plasticity of the muck, and significantly improved the shield thrust, cutterhead torque and tool wear. [ABSTRACT FROM AUTHOR]

Two-stage pressure leaching process is proposed to extract Ni from limonite-type and saprolite- type nickel laterite ore. The recommended conditions for the first stage high pressure acid leaching include acid ore ratio of 330 kg/t, temperature of 250 °C, slurry solid content of 30% and reaction time of one hour. The recommended conditions for the second stage pressure leaching include temperature of 230 °C, reaction time of one hour and slurry solid content of 35%. The nickel extraction rate of first stage high pressure acid leaching and second stage pressure leaching is 97.58% and 83.96% respectively, and the total nickel leaching rate is 93.81%, which greatly improves the utilization rate of nickel laterite ore resources. The Fe and Al concentration in solution can be reduced to below 1 g/L, which can reduce the amount of alkali used in subsequent neutralization processes. [ABSTRACT FROM AUTHOR]