Search Results (113)

Vertical pipes are a significant component of deep-sea mining hydraulic lifting systems, frequently stretching up to thousands of meters. This article employs the coupling approach of computational fluid dynamics for the liquid phase and the Discrete Element Method for the particle phase (CFD-DEM) to simulate solid–liquid two-phase flow in a vertical pipeline, utilizing a scaled vertical lift pipeline model as the study object. By adjusting the conveying parameters and structural factors, the lifting performance of particles and the two-phase flow characteristics under various operating circumstances are examined, and the veracity of the simulation is validated by experimental techniques. The findings reveal that the lifting of particles is impacted by both the conveying parameters and the structural factors. The increase in flow rate can effectively improve the distribution of particles in the pipeline and enhance the followability of particles. The disturbance created by the collision and mixing of particles induced by the change in particle concentration has a tremendous impact on the velocity distribution of the two-phase flow in the pipeline and the pressure distribution of the pipe wall. In addition, there is an ideal lifting flow corresponding to various particle concentrations, which may improve the particle dispersion. The outcome of this research has a certain reference relevance for the selection of the parameters of deep-sea mining lifting systems in the future. Full article

Amid the escalating global demand for raw materials, the gradual exhaustion of terrestrial mineral resources, and the rise in extraction costs and energy consumption, the development of deep-sea mineral resources has become a focal point of international interest. The pipeline lifting mining system, distinguished by its superior mining efficiency and minimized environmental impact, now accounts for over 50% of the total energy consumption in mining operations. Serving as the “heart” of this system, the deep-sea lifting pump’s comprehensive performance (high pressure tolerance, non-clogging features, elevated lift capacity, wear resistance, corrosion resistance, and high reliability, etc.), is critical to transport efficiency, operational stability, and lifespan of the mining system. As a mixed transport pump for solid and liquid media under extreme conditions, its internal flow structure is exceedingly complex, incorporating gas–liquid–solid multiphase flow. A precise understanding of its internal flow mechanisms is essential for breaking through the design limitations of deep-sea lifting pumps and enhancing their operational stability and reliability under various working conditions and multiphase media, thereby providing technical support for advancing global marine resource development and offshore equipment upgrades. This paper comprehensively reviews the design theory, optimization methods, numerical simulations, and experimental studies of deep-sea lifting pumps. It discusses the application of various design optimization techniques in hydraulic lifting pumps, details the multiphase flow numerical algorithms commonly used in deep-sea lifting pumps along with their modified models, and summarizes some experimental methodologies in this field. Lastly, it outlines the forthcoming challenges in deep-sea lifting pump research and proposes potential directions to promote the commercial development of deep-sea mining, thereby offering theoretical and engineering support for the development of deep-sea mining slurry pumps. Full article

Natural lipids with nutritional or therapeutic benefits that also provide desired texture, melting and organoleptic appeal (mouthfeel, skin feel) are difficult to procure for the food and cosmetics industries. Natural Astrocaryum pulp oil (AVP) and kernel fat (AVK) from Guyana were blended without further modification to study the potential of extending the physical functionality of the blends beyond that of crude AVK and AVP. An evaluation of non-lipid components by ESI-MS indicated twenty-four (24) bioactive molecules, mainly carotenoids (90%), polyphenols (9%) and sterols (1%) in AVP, indicating important health and therapeutic benefits. Only trace-to-negligible amounts of these compounds were detected in AVK. The thermal transition phase behavior, solid fat content (SFC), microstructure and textural properties of five AVP/AVL blends were used to construct phase diagrams of the AVK/AVP binary system. Binary phase diagrams constructed from the cooling and heating DSC thermograms of the mixtures and description of the liquidus line indicated a mixing behavior close to ideal with a tendency for order, with no phase separation. Melting onsets, solid fat content and measurements of solid-like texture all predictively increased with increasing AVK content. The descriptive decay parameters obtained for SFC, crystal size, hardness, firmness and spreadability were similar and predictive and indicate the way the binary system structure approaches that of a liquid or a functional solid. The bioactive content of the blends was accurately calculated; the work provides a blueprint for the blending of AVP and AVK to deliver targeted bioactive content, stability, spreadability, texture, melting profile, organoleptic appeal and solid content. SFCs at 20 °C ranged from 9.1% to 39.1%, melting onset from −17.5 °C to 27.8 °C, hardness from 0.1 N to 3.5 N and spreadability from 3.3 N·s to 147.1 N·s; indicating a useful dynamic range of physical properties suitable for bioactive oils to bioactive butters. Full article

Liquid-phase adsorption technology has been widely applied to address environmental problems related to the removal of pollutants from aqueous streams. Simple and effective methods for determining mass transfer parameters, including intra-particle and fluid-to-solid film resistances, are crucial for designing adsorption processes. The efficient simplified diffusion technique (ES technique), based on a completely mixed batch reactor (CMBR), is proposed in this study to address these needs. In this study, we compare three diffusivity (Ds) determination methods: the rigorous diffusion technique (R technique), the simplified diffusion technique (S technique), and the ES technique. Although the simulation results from the R technique are excellent, it is a very complicated and time-consuming approach that is not convenient for practical use. The S technique provides a much simpler approach, but its results are only valid in cases where the contribution of fluid film resistance is negligible (Biot number > 40). The ES technique proposed in this study can overcome those limitations. The estimation errors of the ES technique are significantly smaller than that of the S technique when compared with the R technique. The proposed ES technique would be very useful for field applications to determine diffusivity for aqueous adsorption systems. Full article

The phenomenon of spontaneous dispersion is considered as the cause of the microstratification of metal melts. In a microstratification melt, a violation of long-range order in the arrangement of atoms (LRO) is observed, which corresponds to a dispersed particle size of more than 2 nm. Microseparation occurs due to spontaneous dispersion upon contact of liquid and solid metal or the mixing of two liquid metals. The possibility of spontaneous dispersion was assessed using three different criteria: Volmer’s cr iterion, Rehbinder’s criterion and the diffusion rate criterion. The diffusion rate criterion was obtained on the basis of the theory of rate processes, which describes how diffusing atoms overcome the interphase boundary. It has been established that Al–Sn melts contain colloidal-scale particles (4 nm), and Al–Si and Al–Ge melts contain atomic-scale particles (0.1 nm). For a system with a continuous series of Cu–Ni solid solutions in dispersion (Cu10Ni90—Cu20Ni80), the particle size is 2 nm. The particle size of the ternary eutectic GaInSn in the dispersion (Ga50In50—Ga50Sn50) is 5.6 nm, and the size of immiscible Cu–Fe melts in the dispersion (Cu80Fe20—Cu60Fe40) is 4.8 nm. Long-range order violations (LRO) and the presence of microlayering with colloidal particles larger than 20 nm were observed in the GaInSn ternary eutectic, in the Al–Sn simple eutectic with the preferential interaction of similar atoms, and in Cu–Fe melts with a monotectic phase diagram. Full article

Ultrafast X-ray computed tomography is an advanced imaging technique for multiphase flows. It has been used with great success for studying gas–liquid as well as gas–solid flows. Here, we apply this technique to analyze density-driven particle segregation in a rotating drum as an exemplary use case for analyzing industrial particle mixing systems. As glass particles are used as the denser of two granular species to be mixed, beam hardening artefacts occur and hamper the data analysis. In the general case of a distribution of arbitrary materials, the inverse problem of image reconstruction with energy-dependent attenuation is often ill-posed. Consequently, commonly known beam hardening correction algorithms are often quite complex. In our case, however, the number of materials is limited. We therefore propose a correction algorithm simplified by taking advantage of the known material properties, and demonstrate its ability to improve image quality and subsequent analyses significantly. Full article

Gerty T. and Carl F. Cori discovered, during research on the metabolism of sugars in organisms, the important role of the phosphate ester of a simple sugar. Glucose molecules are released from glycogen—the glucose stored in the liver—in the presence of phosphates and enter the blood as α-D-glucose-1-phosphate (Glc-1PH₂). Currently, the crystal structure of three phosphates, Glc-1PNa₂·3.5·H₂O, Glc-1PK₂·2H₂O, and Glc-1PHK, is known. Research has shown that reactions of Glc-1PH₂ with carbonates produce new complexes with ammonium ions [Glc-1P(NH₄)₂·3H₂O] and mixed complexes: potassium–sodium and ammonium–sodium [Glc-1P(X)_1.5Na_0.5·4H₂O; X = K or NH₄]. The crystallization of dicationic complexes has been carried out in aqueous systems containing equimolar amounts of cations (1:1; X–Na). It was found that the first fractions of crystalline complexes always had cations in the ratio 3/2:1/2. The second batch of crystals obtained from the remaining mother liquid consisted either of the previously studied Na+, K+ or NH₄+ complexes, or it was a new sodium hydrate—Glc-1PNa₂·5·H₂O. The isolated ammonium–potassium complex shows an isomorphic cation substitution and a completely unique composition: Glc-1PH(NH₄)_xK_1−x (x = 0.67). The Glc-1P²⁻ ligand has chelating fragments and/or bridging atoms, and complexes containing one type of cation show different modes of coordinating oxygen atoms with cations. However, in the case of the potassium–sodium and ammonium–sodium structures, high structural similarities are observed. The 1D and 2D NMR spectra showed that the conformation of Glc-1P²⁻ is rigid in solution as in the solid state, where only rotations of the phosphate group around the C-O-P bonds are observed. Full article

The physical properties of sodium cocoyl glycinate (SCG) and the synergistic effects within the SCG/CAPB complex system were investigated using visible–ultraviolet spectrophotometry and a surface tension meter. Analysis of the synergistic parameters of the complex system revealed that the combination of SCG and cocamidopropyl betaine (CAPB) yielded superior results compared to the individual use of SCG. Building upon this, the ternary phase behavior of the SCG/CAPB/H₂O system was further explored. Different lyotropic liquid crystal phases were identified using polarized optical microscopy (POM) and small-angle X-ray scattering (SAXS). Surfactant solutions with varying mass fractions exhibited diverse phase behaviors, including the micellar phase (L₁), micelle–solid mixed phase (L₁-S), hexagonal phase (H), and lamellar phase (L_α), with the insoluble solid phase predominating. The investigation of the ternary phase diagram of SCG/CAPB/H₂O provided valuable guidance for detergent formulation screening, enriched the understanding of sodium cocoyl glycinate complex systems, and further promoted the utilization of amino acid-based surfactants in the field of personal care products. Full article

As an alternative to the traditional advanced oxidation process of adding potassium persulfate (PS) and its activator to the solution separately, in this study, M(AC-PS), an integrated activator and catalyst, was synthesized by vacuum ball milling of PS and activated carbon (AC) to improve the PS’s utilization efficiency. The joint mechanical milling caused a change in the preferentially exposed crystal surface of the PS and the generation of more π-π* structures on the AC, leading to successful and stable connection of the PS onto the surface of the AC. Within 40 min, the M(AC-PS) achieved a degradation rate of 97.3% for tetracycline (TC, 20 mg/L), while the mixed system where AC and PS were separately ball milled achieved only a 53.1% removal of TC. Reactive oxygen species and electrochemical tests showed that M(AC-PS) mainly oxidized TC through non-free radical mechanisms. In M(AC-PS), AC provided oxygen-containing functional groups (e.g., C=O) to activate the PS and electron holes as an electron transfer medium, generating ¹O₂ and promoting electron donation from the TC to enhance the oxidation of the TC. Almost no catalytic components were detected in the solution, indicating that the obtained solid composite material avoids the limitations of solid–liquid interface contact and mass transfer, and then improves the efficiency of activation and catalysis. This study presents a simple and feasible method for obtaining efficient and convenient material for the advanced oxidation treatment of wastewater. Full article

Herein, wheat straw residue and pulping waste liquid were collected from pulping mill and mixed to prepare bio-based granular fuels by using compression molding technology, and to explore the comprehensive utilization of the industrial waste of pulping and papermaking. The effects of pulping waste liquid on granular fuel properties were analyzed systemically. Further study of the function of pulping waste liquid, cellulose and hemicellulose was used to replace wheat straw residue and avoid the interference factors. Therefore, the prediction models of granular fuels were established with influencing factors that included cellulose, hemicellulose and pulping waste liquid. The granular fuels had the best performance with 18.30% solid content of pulping waste liquid. The highest transverse compressive strength of granular fuel was 102.61 MPa, and the activation energy was 81.71 KJ·mol⁻¹. A series of curve fitting prediction models were established to clarify the forming process of granular fuel, and it turned out that the pulping waste liquid could improve the adhesion between solid particles and increase their compression resistance. Full article

This paper deals with the synergy between Nuclear Magnetic Resonance (NMR) spectroscopic investigations and DFT calculations, mainly of NMR parameters. Both the liquid and the solid states are discussed here. This text is a mix of published results supplemented with new findings. This paper deals with examples in which useful results could not have been obtained without combining NMR measurements and DFT calculations. Examples of such cases are tautomeric systems in which NMR data are calculated for the tautomers; hydrogen-bonded systems in which better XH bond lengths can be determined; cage compounds for which assignment cannot be made based on NMR data alone; revison of already published structures; ionic compounds for which reference data are not available; assignment of solid-state spectra and crystal forms; and the creation of libraries for biological molecules. In addition to these literature cases, a revision of a cage structure and substituent effects on pyrroles is also discussed. Full article

A composite lubricating system that combines solid and liquid lubrication can create a synergistic effect by leveraging the strengths of both types of lubricants. Solid lubrication coatings possess advantageous load-bearing abilities and exhibit low volatility. By adopting this approach, the system retains the merits of solid lubrication while simultaneously harnessing the advantages of liquid lubrication. The unique properties of diamond-like carbon coatings (DLCs) offer the potential to create binding locations for lubricant additives by introducing dopant elements that have a high affinity with additives. In the present work, the combined use of europium-doped diamond-like carbon (Eu-doped DLC) with varying atomic concentrations of the dopant element (1.7 at. % and 2.4 at. %) and gadolinium-doped diamond-like carbon (Gd-doped DLC) with different atomic concentrations of the dopant element (1.7 at. % and 2.3 at. %) was studied alongside a pure DLC coating and the incorporation of an ionic liquid (IL) additive in a tribological block-on-ring system. The focus was on the 1-Ethyl-3-methylimidazolium diethylphosphate ionic liquid with a concentration of 1 wt. % in polyalphaolefin (PAO) 8. Among the investigated pairs, the coefficient of friction (CoF) of 1.7 at. % Eu-doped DLC coupled with the IL was the smallest in boundary, mixed, and elastohydrodynamic lubrication regimes. Quantification of wear was challenging due to minimal and localized wear on the DLC coating surfaces. The decrease in friction within the boundary lubrication regime underscores the promise of mechanical systems that integrate 1.7 atomic percent Europium-doped diamond-like carbon coatings with ionic liquids (IL). This study presents a compelling avenue for future scholarly exploration and research efforts focused on reducing friction and improving the efficiency of moving components, particularly in situations where tribological properties exert a substantial influence Full article

Solid-state batteries (SSBs) with Li-ion conductive electrolytes made from polymers, thiophosphates (sulfides) or oxides instead of liquid electrolytes have different challenges in material development and manufacturing. For oxide-based SSBs, the co-sintering of a composite cathode is one of the main challenges. High process temperatures cause undesired decomposition reactions of the active material and the solid electrolyte. The formed phases inhibit the high energy and power density of ceramic SSBs. Therefore, the selection of suitable material combinations as well as the reduction of the sintering temperatures are crucial milestones in the development of ceramic SSBs. In this work, the co-sintering behavior of Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP) as a solid electrolyte with Li-ion conductivity of ≥0.38 mS/cm and LiFePO₄ with a C-coating (LFP) as a Li-ion storage material (active material) is investigated. The shrinkage behavior, crystallographic analysis and microstructural changes during co-sintering at temperatures between 650 and 850 °C are characterized in a simplified model system by mixing, pressing and sintering the LATP and LFP and compared with tape-casted composite cathodes (d = 55 µm). The tape-casted and sintered composite cathodes were infiltrated by liquid electrolyte as well as polyethylene oxide (PEO) electrolyte and electrochemically characterized as half cells against a Li metal anode. The results indicate the formation of reaction layers between LATP and LFP during co-sintering. At T_s > 750 °C, the rhombohedral LATP phase is transformed into an orthorhombic Li_1.3+xAl_0.3−yFe_x+yTi_1.7−x(PO₄)₃ (LAFTP) phase. During co-sintering, Fe³⁺ diffuses into the LATP phase and partially occupies the Al³⁺ and Ti⁴⁺ sites of the NASICON structure. The formation of this LAFTP leads to significant changes in the electrochemical properties of the infiltrated composite tapes. Nevertheless, a high specific capacity of 134 mAh g⁻¹ is measured by infiltrating the sintered composite tapes with liquid electrolytes. Additionally, infiltration with a PEO electrolyte leads to a capacity of 125 mAh g⁻¹. Therefore, the material combination of LATP and LFP is a promising approach to realize sintered ceramic SSBs. Full article

Some amino acid systems are known to exhibit solid solution and/or co-crystal behavior upon crystallization, which significantly affects their phase diagrams and complicates the design of their purification processes. Such behaviors are observed in the l-valine/l-leucine system. In this work, the formation and stability of a 3:1 co-crystal of the two amino acids (designated as V₃L) is further investigated. To accomplish the formation, liquid-assisted grinding, slurry equilibration, and sublimation experiments were performed and analyzed via HPLC and PXRD. Additionally, periodic DFT calculations were used to calculate lattice energies and determine the thermodynamics of possible solid phases. Experimental results show a clear metastability of the investigated V₃L co-crystals when compared to its stable solid solution. The calculations underline the metastability and the possible formation of continuous solid solutions between l-valine and l-leucine since lattice energy differences between pure amino acids and mixed compositions are negligible. This previously unknown phase behavior can be used to assess the influence of V₃L on the amino acid purification process and provides a basis for investigating similar systems with small energy differences between pure and mixed compositions in future studies. In addition, it demonstrates the particular variability of solid phases and their relationships in such simple but biologically important amino acid systems. Full article

The focus of this study was to examine antisolvent effects, which hold significance in particulate processes, such as crystallization and precipitation. In the first section, an experimental investigation revealed that C₁–C₄ primary alcohols significantly reduced the solubility of potassium dihydrogen phosphate (KDP) in water. The solid–liquid equilibria of KDP solutions were determined using an innovative polythermal method, demonstrating time and labor efficiency compared to the traditional isothermal method while maintaining solubility determination quality. This achievement established an efficient tool for high-throughput solvent screening, a crucial aspect of particulate process development. In addition to the experimental approach, in the second part, the influence of these alcohols on KDP solubility was analyzed using the eNRTL thermodynamics model. The model’s estimated parameters confirmed that the addition of these alcohols induced strong non-ideal behavior in the solutions, altered interactions between solute species and solvent components, and reduced KDP solubility. Under the effects of these alcohols, KDP solubility generally increased with the length of the alkyl chain in the added alcohols, although methanol deviated from this observation. Furthermore, the present work also discussed the limitation of the well-known Bromley’s equation, particularly when applied for KDP in alcohol–water mixed solvents. Consequently, binary and ternary systems consisting of KDP, water, and C₁–C₄ primary alcohols were successfully modeled using eNRTL. Furthermore, it was determined that the obtained model was insufficient for quaternary systems with a higher alcohol content, particularly when high-order interactions were neglected as in the cases of binary and ternary systems. In short, these investigated alcohols have potential for future applications in the design of particulate processes, with a particular emphasis on antisolvent crystallization. Full article