Solute Concentration Research Articles

Metastable precipitation and ion–extractant transport in liquid–liquid separations of trivalent elements

The extractant-assisted transport of metal ions from aqueous to organic environments by liquid-liquid extraction has been widely used to separate and recover critical elements on an industrial scale. While current efforts focus on designing better extractants and optimizing process conditions, the mechanism that underlies ionic transport remains poorly understood. Here, we report a nonequilibrium process in the bulk aqueous phase that influences interfacial ion transport: the formation of metastable ion-extractant precipitates away from the liquid-liquid interface, separated from it by a depletion region without precipitates. Although the precipitate is soluble in the organic phase, the depletion region separates the two and ions are sequestered in a long-lived metastable state. Since precipitation removes extractants from the aqueous phase, even extractants that are sparingly soluble in water will continue to be withdrawn from the organic phase to feed the aqueous precipitation process. Solute concentrations in both phases and the aqueous pH influence the temporal evolution of the process and ionic partitioning between the precipitate and organic phase. Aqueous ion-extractant precipitation during liquid-liquid extraction provides a reaction path that can influence the extraction kinetics, which plays an important role in designing advanced processes to separate rare earths and other minerals.

The effect of peristalsis on dispersion in Casson fluid flow

The present study examines the peristaltic flow of a non-Newtonian (Casson) fluid and solute transport through a flexible tube. Using the long-wavelength approximation, an analytical solution for the Casson fluid velocity is obtained in the axial and radial directions. Then, a numerical solution to the solute concentration is computed using the standard Galerkin finite element method (FEM) for the case of solutal convection-diffusion and the Discontinuous Galerkin FEM for the pure convection case. Graphical results are presented for the axial and local solute concentrations, and the influence of peristaltic wave amplitude, volumetric flow rate, modified Péclet number, time, yield stress, and pertinent initial condition parameters were investigated.

Mesosilicate materials for environmental applications: Adsorption separation analysis via hybrid computational and machine learning tools

In this extensive analysis, we delve into the utilization of advanced hybrid model for molecular separation description via mesoporous materials. The process considered here is adsorption which is utilized for molecular separation in liquid solution. Data for adsorption are obtained in terms of solute concentration by solving mass transfer equations numerically. Then, the data is used for training and validation of several machine learning techniques to establish the hybrid model. For machine learning model, several methods are utilized including three robust tree-based ensemble models, namely Gradient Boosting (GB), Random Forest (RF), and Extra Trees (ET). The methos were utilized to tackle the challenging task of predicting chemical concentrations in a dataset comprising an array of over 19,000 data. These data points are characterized by input variables representing coordinates (x and y), while the output variable encapsulates chemical concentration (C). By subjecting these models to a meticulous optimization process, we achieved substantial enhancements in their predictive capabilities. RF emerged as the standout performer, boasting a remarkable R2 score of 0.99902. ET and GB also demonstrated commendable performance improvements, underscoring the versatility of tree-based ensemble models in delivering precise and reliable predictions for chemical concentrations within intricate and multifaceted datasets.

WENO scheme on characteristics for the equilibrium dispersive model of chromatography with generalized Langmuir isotherms

Column chromatography is a laboratory and industrial technique used to separate different substances mixed in a solution. Mathematically, it can be modeled using non-linear partial differential equations whose main ingredients are the adsorption isotherms, which are non-linear functions modeling the affinity between the different substances in the solution and the solid stationary phase filling the column. The goal of this work is twofold. Firstly, we aim to extend the techniques of Donat, Guerrero and Mulet (2018) [3] to other adsorption isotherms. In particular, we propose a family of generalized Langmuir-type isotherms and prove that the correspondence between the concentrations of solutes in the liquid phase (the primitive variables) and the conserved variables is well defined and admits a global smooth inverse that can be computed numerically. Secondly, to establish the well-posedness of the mathematical model, we study the eigenstructure of the Jacobian of the mentioned correspondence and use this characteristic information to get oscillation-free sharp interfaces on the numerical approximate solutions. To do so, we determine the structure of the Jacobian matrix of the system and use it to deduce its eigenstructure. We combine the use of characteristic-based numerical fluxes with a second-order implicit-explicit scheme proposed in the cited reference and perform some numerical experiments with Tóth's adsorption isotherms to demonstrate that the characteristic-based schemes produce accurate numerical solutions with no oscillations, even when steep gradients appear in the solutions.

Osmotic Pressure and Its Biological Implications.

Gaining insight into osmotic pressure and its biological implications is pivotal for revealing mechanisms underlying numerous fundamental biological processes across scales and will contribute to the biomedical and pharmaceutical fields. This review aims to provide an overview of the current understanding, focusing on two central issues: (i) how to determine theoretically osmotic pressure and (ii) how osmotic pressure affects important biological activities. More specifically, we discuss the representative theoretical equations and models for different solutions, emphasizing their applicability and limitations, and summarize the effect of osmotic pressure on lipid phase separation, cell division, and differentiation, focusing on the mechanisms underlying the osmotic pressure dependence of these biological processes. We highlight that new theory of osmotic pressure applicable for all experimentally feasible temperatures and solute concentrations needs to be developed, and further studies regarding the role of osmotic pressure in other biological processes should also be carried out to improve our comprehensive and in-depth understanding. Moreover, we point out the importance and challenges of developing techniques for the in vivo measurement of osmotic pressure.

Coupling strengthening mechanism of precipitate and solute atoms in edge dislocation motion of Al-Mg-Si alloy

To investigate the coupling strengthening mechanism of precipitate and Cu solute atoms in Al-Mg-Si alloy, the molecular dynamics model of edge dislocation motion interacted with precipitate and Cu solute atoms was established. The dislocation length is increased in the dislocation-precipitate interaction due to the bending and bowing of the edge dislocation around the precipitate. No coupling between precipitate and solute can be found in material strengthening in cases with lower solute concentrations. The exponential effect of the coupling effects between precipitate and solute on material strengthening is found when the solute concentration is increased above 0.3.at% at room temperature. The change of the edge dislocation caused by solute atoms around the precipitate is the key reason for the strengthening coupling effect. Furthermore, the effects of temperature variations on the coupling effect are more pronounced than the effects of shear strain rate variations. When the temperature is increased from 200K to 500K, the critical ratio of solute and precipitate strengthening is decreased from 1.5 to 0.4.

Simulation of pulsatory liposome working using a linear approximation for transmembrane pore dynamics

This paper presents an analytical solution of the differential equations describing the pulsatory liposome dynamics. We consider a unilamellar liposome filled with an aqueous solution of osmotic solute inserted in a hypotonic aqueous medium. Due to the osmosis process the liposome has a cyclic evolution. The lipid vesicle swells to a critical size, at which point a transbilayer pore suddenly appears. Part of the internal solution leaks through this pore. The liposome relaxes and returns to the initial size. The swelling starts again and the liposome goes through a periodical process. The swelling of the liposome is described by a differential equation. The appearance of the pore changes the evolution of the liposome. The internal solution comes out through the pore and the liposome starts its deflation (relaxation). The evolution of the pore has two phases: first, the radius of the pore increases to its maximum value, then the radius decreases until it disappears, and the liposome reaches its initial size. During each cycle, the liposome will release a quantity (a pulse) of the solution from its interior. All the processes which contribute to the liposome relaxing and its coming back to the initial size are described by three differential equations. This system of differential equations can be integrated using numerical methods. The functions – which model our biological engine in three stages, are as follows: R(t) - the liposome radius, r(t) - the pore radius, C(t) - solute concentration, Q(t) - the osmotic solute amount inside the liposome. The graphs representing these functions contain important linear portions, which suggested a solution using analytical methods. Based on some analytical methods, we solve these equations, and their explicit solutions are validated by comparing with numerical results of previous studies.

Irrigation impact on water quality and aquifer vulnerability in Kala Oya basin, Sri Lanka

The impact of precipitation and irrigation return flow on water quality and groundwater vulnerability was investigated in the Kala Oya basin, Sri Lanka using the Weighted Arithmetic Water Quality Index, DRASTIC Index, and isotope hydrology. Groundwater and surface water were analyzed for water quality parameters and stable isotopes (18O and 2H) in dry and wet seasons. In both seasons, neutral to alkaline water was observed. Electrical conductivity (EC) and major ions were higher in shallow (EC: 718.3 ± 323.8 μS/cm; Ca2+: 49.54 ± 32.99 mg/L) and deep groundwater (EC: 708.1 ± 321.5 μS/cm; Ca2+: 37.06 ± 11.21 mg/L) than in surface water (EC: 371.7 ± 154.4 μS/cm; Ca2+: 29.66 ± 11.64 mg/L), while similar values of EC and major ions were reported in both shallow and deep groundwater samples. Ca–Mg–HCO3 was the dominant groundwater type which was derived from silicate and carbonate rock weathering. Observations in the wet season revealed δ2H ranged from −47.97 to −16.71‰ and δ18O ranged from −7.56 to −2.87‰, while in the dry season, δ2H ranged from −44.90 to −14.06‰, and δ18O ranged from −7.69 to −2.08‰. The enriched δ18O and δ2H groundwater values were mainly the result of progressive evaporative concentration of the heavier isotopes before water infiltration and groundwater recharge. The solute concentrations were enriched in groundwater by agricultural irrigation returns and associated evaporation indicating the influence of irrigation return flow on groundwater. It is suggested that agricultural practices increase groundwater vulnerability, which recommends special attention to long-term groundwater quality and quantity monitoring, hydrological modelling, land-use planning, and the development of sustainable policies in the basin.

Microstructure, hardness, and electrical resistivity of Al-Cu alloy fabricated via wire arc additive manufacturing

Additive manufacturing (AM) techniques allow for greater design freedom than is possible with conventional manufacturing processes. Components fabricated via AM can be compact and more potent for electrical applications. This study used cold metal transfer (CMT) based wire arc additive manufacturing (WAAM) to build the WAAM 2319 wall. The microstructure is mainly composed of equiaxed and columnar dendrites along with a small fraction of pores. Precipitated θ phases formed due to complex thermal cycles during WAAM. The hardness of the WAAM 2319 alloy ranged between 68 HV0.2 to 86 HV0.2. The electrical resistivity of WAAM 2319 was 6.72±0.23 µΩ.cm resulting in the reduced conductivity of 25.66±1.10%IACS compared to the wrought AA2219 alloy having 30%IACS. The decrease in electrical conductivity is attributed to the presence of coarse precipitates along with dendritic microstructure and copper solute concentration. Thus, WAAM-processed Al-Cu alloys can be used for future electrical applications.

Diffusiophoretic Behavior of Polyelectrolyte-Coated Particles.

Diffusiophoresis, the movement of particles under a solute concentration gradient, has practical implications in a number of applications, such as particle sorting, focusing, and sensing. For diffusiophoresis in an electrolyte solution, the particle velocity is described by the electrolyte relative concentration gradient and the diffusiophoretic mobility of the particle. The electrolyte concentration, which typically varies throughout the system in space and time, can also influence the zeta potential of particles in space and time. This variation affects the diffusiophoretic behavior, especially when the zeta potential is highly dependent on the electrolyte concentration. In this work, we show that adsorbing a single bilayer (or 4 bilayers) of a polyelectrolyte pair (PDADMAC/PSS) on the surface of microparticles resulted in effectively constant zeta potential values with respect to salt concentration throughout the experimental range of salt concentrations. This allowed a constant potential model for diffusiophoretic transport to describe the experimental observations, which was not the case for uncoated particles in the same electrolyte system. This work highlights the use of simple polyelectrolyte pairs to tune the zeta potential and maintain constant values for precise control of diffusiophoretic transport.

Application of a new chitosan derivative for adsorption of copper (II) and oxyanions of chromium (VI)

This study describes the synthesis of a new bioadsorbent from chitosan using ethylenediaminetetraacetic dianhydride (EDTAD) as a modifying agent and its successful application for removal of a cationic ion (copper (II) (Cu2+)) and oxyanions of chromium (VI) (Cr6+) from single-component aqueous systems. The new multifunctionalised chitosan derivative (C1) was produced through chemical modification of the primary hydroxyl function of chitosan with EDTAD to introduce carboxylic and tertiary amine functional groups, maintaining the secondary amines on the chitosan surface. Such a transformation was important not only to increase the adsorptive potential of chitosan but also to allow C1 to be used in acidic media, thus solving the problem of solubility of most chitosan derivatives. C1 was characterised by spectroscopic methods. The effects of solution pH, contact time and initial solute concentration on the removal of copper (II) and chromium (VI) by C1 were investigated in aqueous solutions. C1 showed an experimental maximum adsorption capacity of 106 mg/g for copper (II) and 194 mg/g for chromium (VI).

Modeling of deionization of aqueous compounds using electrodialysis process (data collection for enhanced clarity)

ABSTRACT The deionization process is increasingly recognized as a solution to global water shortages. This study aims to investigate the impact of various parameters on the deionization efficiency. Specifically, volume flow rates (F) were tested (1, 2.5, 5, 10, 15, and 20 ml min−1), solute concentrations (C) (200, 500, and 1000 mg l−1), temperatures (T) (50, 60, and 70°C), voltages (V) (10, 20, and 30 V), and pressures (P) (200, 400, and 800 Pa). In another experiment examined F (100, 250, and 500 mol l−1 m2), V (0.1, 0.5, and 1 V), C (100, 200, 300, 400, and 500 moles m3), and time durations (D) (16, 32, 48, 64, 80, and 96 min). These experiments aimed to determine the separation percentage of potassium chloride cations and anions and were based on data extracted from scientific articles. In the subsequent step, the ANFIS model with the FCM network creation method and the error backpropagation training algorithm was employed to evaluate the impact of each cell input on the separation percentage, output flux, and the separation percentage of potassium chloride cations and anions. This evaluation was conducted through 31 and 15 iterations, respectively. Based on the evaluation criteria, it was observed that the volume flow rate as the sole input yielded the highest prediction accuracy for the separation percentage and output flux. Additionally, the FCTVP model results indicated a slight reduction in the error criteria compared to the FCTV, FCT, FC, and single models. Consequently, it can be concluded that the cell pressure factor may play a decisive role, either reducing or increasing the separation process (R2 = 0.93,MBE = −0.3, and RMSE = 6.4), as well as the output flux (R2 = 0.85, MBE = 0.0003, and RMSE = 0.07). Furthermore, the statistical criteria values of the FVCT model for the separation percentage of potassium chloride cations and anions demonstrated a proper correlation (R2 = 0.96 and 0.95), slight underestimation, and low error MBE = −0.57 and −1.2) (RMSE = 15.2 and 18.5, respectively).

Effect of different ultrasound conditions and other parameters on solids gain, water loss, and properties of osmotically dehydrated carrots

AbstractOsmotic dehydration (OD) of carrots was studied by varying the OD conditions (ultrasound as pretreatment [USP], ultrasound‐assisted OD [USOD], and OD without ultrasound [no treatment]), solute concentration (50, 60, and 70°Brix) and solid‐to‐solution ratio (1:3, 1:4, and 1:5). The osmotically dehydrated carrots obtained from the different combinations were then analyzed for solid‐gain (SG) and water loss. Color and texture measurements along with carotenoid content were also studied. Among the different solid‐to‐solution ratios (1:3, 1:4, and 1:5), samples dehydrated with 1:4 yielded the best result for different tests. USOD samples (1:4) gave significantly (p < 0.05) better results for water‐loss (68.74%) and SG (16.57%) as compared to SG of USP (12.46%) and SG of non‐treated samples (11.6%). USOD samples underwent the least amount of color change but had significantly higher values of hardness (240.38 N) than other treatments. The yield of total carotenoids was also significantly (p < 0.05) higher in the USOD samples (22.30 mg/100 g) when compared with USP (18.27 mg/100 g) and non‐treated samples (13.94 mg/100 g). The better quality of products from USOD treatment in terms of color, texture, and nutrition can make it a popular choice in the food industry for various applications.Practical applicationsOsmotic dehydration (OD) is a useful technique to preserve the nutritional and sensory qualities of carrots and extend its shelf life. OD is a time‐consuming process and the rate of mass transfer from foods can be increased when OD is combined with other processes. Ultrasound (US) processing is a non‐thermal process that can be used to increase the mass transfer rate during the OD process. In the present work, US was applied as a pretreatment before carrying out the OD process and during the OD process, that is, US was applied in the osmotic solution after putting the carrot slices to see which method was better in increasing the mass transfer rate and preserving the quality of the dehydrated carrots. The findings will help in deciding the proper way for US to be applied for the OD process for carrots and can be extended to other fruits and vegetables.

Chemistry, Growth, and Fate of the Unique, Short‐Lived (2019–2020) Water Lake at the Summit of Kīlauea Volcano, Hawaii

AbstractLess than a year after the 2018 Kīlauea caldera collapse and eruption, water appeared in newly deepened Halemaʻumaʻu crater. The lake—unprecedented in the written record—grew to a depth of ∼50 m before lava from the December 2020 eruption boiled it away. Surface water heightened concerns of potential phreatic or phreatomagmatic explosions but also offered a new means of possibly identifying eruption precursors. The U.S. Geological Survey Hawaiian Volcano Observatory (HVO) monitored the lake via direct visual observation, webcams, thermal imaging, colorimetry, and laser rangefinders. HVO also employed uncrewed aircraft systems to sample the water and measure near‐lake gas composition. The lake's δD and δ18O indicate a groundwater source with substantial evaporation. The initial sample had a salinity (total dissolved solids concentration) of 71,000 mg/L and was rich in sulfate (∼53,000 mg/L), iron (∼500 mg/L), and magnesium (∼10,000 mg/L). Subsequent samples were slightly more dilute. The water's pH (∼4), δ34S (+4.3‰), and surface temperatures (up to 85°C) suggest, rather than significant scrubbing of magmatic volatiles, leaching of basalt and reactions with sulfate minerals resulted in high concentrations of sulfate and other solutes. Thermodynamic modeling and precipitate mineralogy indicate that water composition was controlled by iron oxidation and sulfate dissolution. Although the lake exhibited no detectable precursors before the next eruption, and phreatic or phreatomagmatic explosions did not materialize, our multi‐parameter approach to monitoring yielded an enhanced understanding of the hydrologic, geologic, and magmatic conditions that led to the formation of the unique and short‐lived lake.

Weathering Incongruence in Mountainous Mediterranean Climates Recorded by Stream Lithium Isotope Ratios

AbstractLithium isotope ratios (δ7Li) of rivers are increasingly serving as a diagnostic of the balance between chemical and physical weathering contributions to overall landscape denudation rates. Here, we show that intermediate weathering intensities and highly enriched stream δ7Li values typically associated with lowland floodplains can also describe small upland watersheds subject to cool, wet climates. This behavior is revealed by stream δ7Li between +22.4 and +23.5‰ within a Critical Zone observatory located in the Cévennes region of southern France, where dilute stream solute concentrations and significant atmospheric deposition otherwise mask evidence of incongruence. The water‐rock reaction pathways underlying this behavior are quantified through a multicomponent, isotope‐enabled reactive transport model. Using geochemical characterization of soil profiles, bedrock, and long‐term stream samples as constraints, we evolve the simulation from an initially unweathered granite to a steady state weathering profile which reflects the balance between (a) fluid infiltration and drainage and (b) bedrock uplift and soil erosion. Enriched stream δ7Li occurs because Li is strongly incorporated into actively precipitating secondary clay phases beyond what prior laboratory experiments have suggested. Chemical weathering incongruence is maintained despite relatively slow reaction rates and moderate clay accumulation due to a combination of two factors. First, reactive primary mineral phases persist across the weathering profile and effectively “shield” the secondary clays from resolubilization due to their greater solubility. Second, the clays accumulating in the near‐surface profile are relatively mature weathering byproducts. These factors promote characteristically low total dissolved solute export from the catchment despite significant input of exogenous dust.

Progressive stirred freeze concentration: Effect of operative parameters on vital statistics of beer

AbstractFreeze concentration (FC), a low‐cost alternative technology to separate and concentrate high‐value compounds, was applied to three distinct craft ale beer styles—Witbier, Bitter, and Porter—to investigate its impact on vital beer statistics. A central composite design with freezing temperature and ice fraction as factors was employed, with response surface analysis revealing significant effects on the average ice growth rate (), concentration index (CI), and average distribution coefficient () of ethanol, total solids, color, and bitterness in the liquid fraction. Results showed that ice fraction primarily influenced solute concentrations and increased with ice fraction due to water removal. Freezing temperature affected . The type of beer had a significant impact on color and bitterness, reflecting the specific style parameters. Furthermore, response optimization yielded conditions that significantly altered beer statistics, leading to changes in ethanol content, total solids, color, and bitterness, possibly classifying them as new beer styles. The study demonstrates the potential of FC to influence the beer characteristics and broaden the range of beer styles.Practical applicationsInnovations in science and technology, added to the search for new beer styles, promote the development of new products in the beer industry. In this article, a potential use of the freeze concentration technology was identified for the development of new concentrated beer products. The impact of progressive stirred freeze concentration in three craft beers was studied. First, obtaining a concentrated beer from this technique was possible, with a higher concentration of total solids and ethanol. In addition, the vital statistics of beer could be modified using freeze concentration to obtain novel concentrated beer products.

An Evaluation of the Relationship between Membrane Properties and the Fouling Mechanism Based on a Blocking Filtration Model

Microfiltration plays an increasingly important role in various fields. Consequently, elucidating the mechanism of membrane fouling has emerged as a pivotal issue that needs to be resolved. In this study, a blocking filtration model was employed to evaluate the effects of membrane properties on the fouling mechanism during the microfiltration of representative polysaccharides, namely sodium alginate, pectin, and xanthan gum. Microfiltration membranes composed of hydrophilic and hydrophobic PVDF, mixed cellulose ester, as well as hydrophilic and hydrophobic PTFE were used as filter media. The flux decline behavior was significantly affected by the membrane properties, with hydrophilic membranes exhibiting a slower decrease in filtration rate. The model analysis revealed a correlation between the blocking characteristic values and the membrane properties. Although the blocking index n showed membrane material dependence, the values of this parameter remained consistent across various filtration conditions, including the wettability of the membrane surface, solute concentration, and pressure (pectin: n = 1.86, 1.85, 1.50, and 1.50 for hydrophilic PVDF, hydrophobic PVDF, hydrophilic PTFE, and hydrophobic PTFE, respectively). The resistance coefficient k was influenced by the characteristics of the membrane surface; the k values of the hydrophobic membranes were higher than those of the hydrophilic ones (pectin: k = 0.00084, 0.00725, 0.00714, and 0.0384 s1−n/cm2−n for hydrophilic PVDF, hydrophobic PVDF, hydrophilic PTFE, and hydrophobic PTFE, respectively). The model calculations, based on the values of n and k, demonstrated a relatively good agreement with the experimental data.

Cryopreservation of human semen by inherently-controlled icing probability: Or how the surface profile of superhydrophobic carbon soot coatings and the sperm volume affect the outcome of slow freezing?

The restoration of initial functionality of human spermatozoa subjected to cryopreservation is challenging, because the deleterious intracellular icing and the occurrence of osmotic shocks due to prolonged exposure to increased concentrations of intracellular solutes are oppositely dependent on the cooling rate. This longstanding problem could be overcome if using superhydrophobic soot coatings delaying the heat transfer rate, reducing the ice formation probability and triggering balanced and timely dehydration of the cells, but the effect of their surface profile and sperm volume on the success rate of slow freezing is unclear. Here, we show for the first time that the two-factor freezing injury is entirely avoidable by tailoring the solid-to-gas voids (pores) fraction in the soot, leading to increased nucleation free energy barrier, presumable incipiency of ice crystals with controllable shape and size and hence, fully (100 %) recovered post-thaw sperm motility. It is demonstrated that the reason for such a unique scientific result is the selection of soot coatings with appropriate morphochemical features, hypothetically (not directly proven yet) inducing equilibrium among the solution composition and ice crystals formation, retarding the undesirable compression of liquid-filled “slush ice” channels surrounding the cytoplasm and impeding the ice recrystallization. The novel insights introduced in this article open endless horizon for customizing and revolutionizing the technical protocols in cryobiology.

The Treatment of Natural Calcium Materials Using the Supercritical Antisolvent Method for CO2 Capture Applications

The potential of the supercritical antisolvent micronization (SAS) technique was evaluated for the production of CaO-based particles with a size and a physical structure that could enable high performance for CO2 capture through the calcium looping process. Two sources of calcium derivative compounds were tested, waste marble powder (WMP) and dolomite. The SAS micronization of the derivate calcium acetate was carried out at 60 °C, 200 bar, a 0.5 mL min−1 flow rate of liquid solution, and 20 mg mL−1 concentration of solute, producing, with a yield of more than 70%, needle-like particles. Moreover, since dolomite presents with a mixture of calcium and magnesium carbonates, the influence of the magnesium fraction in the SAS micronization was also assessed. The micronized mixtures with lower magnesium content (higher calcium fraction) presented needle-like particles similar to WMP. On the other hand, for the higher magnesium fractions, the micronized material was similar to magnesium acetate micronization, presenting sphere-like particles. The use of the micronized material in the Ca-looping processes, considering 10 carbonation-calcination cycles under mild and realistic conditions, showed that under mild conditions, the micronized WMP improved CaO conversion. After 10 cycles the micronization, WMP presented a conversion 1.8 times greater than the unprocessed material. The micronized dolomite, under both mild and real conditions, maintained more stable conversion after 10 cycles.

Solute Effects on Growth Restriction in Dilute Ferrous Alloys

The effect of dilute solute additions on growth restriction in binary ferrous alloys has been assessed by means of the heuristic growth restriction parameter (β) modelling framework (Fan et al. in Acta Mater. 152, 248–257, 2018). The CALPHAD (CALculation of PHAse Diagrams) methodology (Kaufman and Bernstein in Computer Calculation of Phase Diagrams, 1970) has been used to calculate β values from the liquidus slope m and the equilibrium distribution coefficient k values, at first approximation, in conjunction with the liquid-to-solid fraction to obtain true β values. Critical solute concentrations, below which solidification becomes partitionless, have also been calculated. Among 23 dilute binary ferrous alloy systems investigated, the five most efficient solutes on grain refinement are B, Y, O, S and C. A negative correlation, or inverse relationship, was observed between the true β values and the grain size values obtained from a study on experimental multicomponent dilute ferrous alloy systems (Li et al. in Metall. Mater. Trans. A 49 A, 2235–2247, 2018).