Amount Of Mg Research Articles

High‐Throughput Study of the Phase Constitution of the Thin Film System Mg–Mn–Al–O

The increasing importance of recycling makes the recovery of valuable elements from slags interesting. The concept of engineered artificial minerals aims at the formation of phase(s) with a high content of the to‐be‐recovered element(s) from slags of pyrometallurgical recycling processes. For this, understanding the phase constitution of the slag systems, such as the spinel‐forming subsystem Mg–Mn–Al–O from Li‐ion battery recycling, is of great importance. Herein, the phase constitution is investigated using a thin film materials library (ML) that covers the composition space (Mg14−69Mn11−38Al14−74)Ox. High‐throughput energy‐dispersive X‐ray spectroscopy and X‐ray diffraction confirm the formation of the spinel solid solution phase for a wide composition space. The Mn oxidation state is shown to be a mixture of Mn2+ and Mn3+ by analyzing Mn 2p3/2 spectra from X‐ray photoelectron spectroscopy. For one measurement area of the ML containing equal atomic amounts of Mg, Mn, and Al, transmission electron microscopy shows columnar spinel grains with Mg, Mn, and Al evenly distributed. Based on these results, it is suggested that the high likelihood of spinel formation in slags can be influenced by controlling the Mn oxidation state to allow the formation of desirable engineered artificial minerals for Li recovery.

Migration of transition metals and potential for carbon mineralization during acid leaching of processed kimberlite from Venetia diamond mine, South Africa

Carbonation of mafic and ultramafic rocks and mineral wastes provides a permanent way to sequester excess atmospheric CO2. Recent research has shown that this method also offers the potential for enhanced recovery of critical metals from mine tailings. In this study, processed kimberlite from the Venetia diamond mine (South Africa) was used in column acid leaching experiments to assess both its carbonation potential and whether critical metals such as nickel could be recovered during mineral carbonation. Processed kimberlite was treated daily with one pore volume of either deionized water or dilute hydrochloric acid (0.04 M, 0.08 M, 0.12 M and 0.16 M) for 28 days. Iron-rich yellow precipitates consistent with yellow ground formed during the experiments both at the top of the residue columns (corresponding to the inlets of the columns) and within the leachates collected from the bases of columns. The carbonation potential and mobility of transition metals were investigated using a combination of quantitative X-ray diffraction (XRD) using Rietveld refinements, inductively coupled plasma mass spectrometry (ICP-MS), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDXS), transmission electron microscopy (TEM) coupled with EDXS, and synchrotron-based X-ray fluorescence microscopy (XFM). Our results show that the high proportion of clay minerals (e.g., lizardite, smectite, talc, chlorite) in the processed kimberlite act as the primary source for Mg and transition metals such as Ni; however, calcite dissolution is the main source for Ca. The amount of Mg and Ca extracted from processed kimberlite increases with HCl concentration. If acid leaching of processed kimberlite were used at Venetia, the amount of Mg leached from clay minerals would provide an estimated CO2 offset potential ranging from 2.1 to 15.8 % of the mine's total annual emissions. The leached Ca from silicate dissolution could also provide an estimated CO2 offset potential ranging from 2.1 to 8.1 % of the mine's total annual emissions. However, the amount of CO2 released by calcite dissolution during this process is equivalent to 2.1–14.3 % of total annual CO2 emissions at Venetia., thus resulting in a net estimated CO2 offset potential of 2.1–9.6 % if the Ca released from calcite could not be recarbonated. If all of the Ca could be reprecipitated as calcite, the acid leaching techniques employed in this study could offset 4.2–23.9 % of the Venetia mine's CO2 emissions. Ultimately, greater concentrations and/or amounts of acid may be used to access more of the offset potential of Mg phyllosilicates in kimberlite, but the CO2 released by calcite dissolution must also be won back by recarbonation.

Effects of simulated groundwater solutions with different Ca2+ to Mg2+ concentration ratios on asymmetric electrodeposition in concrete

Electrodeposition is an emerging and unique method for the repair of concrete cracks, in particular, with great potential for the repair of aged asymmetric subsurface structures. However, the effect of groundwater solutions on the effectiveness of concrete repair by electrodeposition is not clear. Using an asymmetric electrodeposition repair device, this paper investigates the effect of simulated groundwater solutions with different Mg2+ to Ca2+ concentration ratios on the effectiveness of electric field-induced ettringite for repairing concrete cracks. Results show that the simulated groundwater solution has a negligible effect on the macroscopic repair effect on the electrolyte solution side, but allows a certain amount of Mg(OH)2 and CaCO3 precipitation to be generated on the simulated solution side. Meanwhile, compared with the deionized water group, the permeability coefficient is reduced from 2.05×10−6 cm/s to less than 7.65×10−7 cm/s at the repair age of 14 days. The total impedance is enhanced from 1322 KΩ to more than 1658 KΩ, with the lower the Mg2+ to Ca2+ concentration ratios, the lower the permeability coefficient and the higher the total impedance. Microstructure analysis suggests that as the concentration ratio of Mg2+ to Ca2+ decreases, the content of loose porous Mg(OH)2 decreases and the content of dense CaCO3 increases on the simulated solution side. Moreover, the size of the Mg(OH)2 particles on the simulated solution side, becomes larger and the amount of production decreases while the CaCO3 increases and changes from aragonite to calcite type.

Comet 81P/Wild 2 dust impactors of Stardust turnip-like tracks analogous to cluster IDPs

We measured oxygen isotope ratios of 16 silicate fragments from seven aerogel tracks (turnip-like type B tracks 77, 149, 172, 191, and 220; carrot-like type A tracks 22 and 175) of the comet 81P/Wild 2 collector from NASA’s Stardust mission using secondary ion mass spectrometry. Thirteen were prepared by ultramicrotomy; three from track 220 were prepared by sputtering resin blocks using a SIMS Kohler beam, a new procedure aiming to mine as many cometary particles encased in aerogel/resin as possible. Combining new and literature results, we recognized that most silicate fragments of individual type B tracks have diverse mineralogy but consistent mass-independent fractionation of oxygen isotopes (Δ17O = δ17O − 0.52 × δ18O). These observations suggest that their impactors are loosely bound aggregates of unequilibrated materials originating mainly from similar protoplanetary disk regions, resembling the cluster IDP U2-20-GCA. Furthermore, silicate fragments from type A track 22 have almost identical mineralogy and Δ17O values, confirming that its impactor is a single chondrule-like fragment. The terminal particle of type A track 175 is pure forsterite with Δ17O of ∼ –23 ‰.Six iron-rich fragments of this study have positive oxygen isotope ratios (Δ17O∼ +2 ‰) and ordinary chondrite chondrule-like olivine compositions. Together with five similar fragments in the literature, a unique population (Mg# ≤ 86) of Wild 2 fragments that resemble chondrules from the inner solar system (O-E-R) chondrites or the outer solar system CH-CB chondrites was identified. The remaining 16O-poor Wild 2 fragments are Mg# ≥ 79 silicates with Δ17O ∼ –2 ‰ and a small amount of Mg# ≤ 79 silicates with Δ17O ∼ 0 ‰, which are most consistent with CR chondrite chondrules. Thus, we conclude that in addition to the possible major source of CR chondrite chondrule-like materials, the inner solar system or CH-CB chondrule-like materials are a minor component of comet Wild 2, like the cluster IDP U2-20-GCA.

Effects of Clay Minerals on Enzyme Activity as a Potential Biosensor of Soil Pollution in Alice Township

Inadequate waste management and illegal trash dumping continue to be the leading causes of severe environmental pollution. Human exposure to harmful heavy metals has emerged as a serious health concern on the continent. Some people in Alice, a small town, grow their food in home gardens. They use animal manure and compost derived from soil obtained from landfills to enhance the fertility of the garden soil. Heavy metal heaps in garbage disposals are constantly present, releasing dangerous amounts of metal into the environment. The harmful effects of heavy metals on plants lead to unsanitary conditions and environmental problems. Animals and people who consume these vegetables may also be at risk for health problems. Assessing the soil’s enzyme activity can potentially lessen the negative effects of the accumulated pollutants and improve the soil’s overall health and quality. Soil enzymes are biologically active components that have a catalytic impact and are released from root exudates, crop residues, and animal remains. The activity of enzymes serves as an excellent bioindicator of soil cleanliness and quality because they are sensitive to heavy metals. X-ray diffraction (XRD) was used to quantify the mineral elements in soil using 40 kV parallel beam optics, 30 mA, and CuKα radiation. Meanwhile, the activity of the enzyme was essayed in different coupled substrates. Thirteen (13) clay minerals were found, including Talc 2M, Kaolinite 2M, and Chlorite Lawsonite Muscovite 2M1. The detected trace elements have high concentration levels that exceed the World Health Organization’s (WHO) allowed levels. The identified elements affected the enzyme activity at different levels. The Mn, Al, Si, V, Ti, and Ca negatively affect soil enzyme activity, specifically invertase (INV). However, the amount of Mg, K, Fe, and Zn showed a slightly positive effect on the same enzyme (INV). According to this view, these elements come from several sources, each with a particular impact on soil contamination and enzyme activity. High levels of heavy metals in this study may be due to improper waste disposal, limited recycling opportunities, lack of public awareness, and inadequate enforcement of waste management regulations. It is essential to employ Fourth Industrial Revolution (4IR) technologies, correct disposal techniques, suitable agricultural methods, preventive regulations, and efficient waste management to mitigate the negative effects of heavy metals on the environment.

Improvement of corrosion resistance and adhesion of hydroxyapatite coating on AZ31 alloy by an anodizing intermediate layer.

The primary objective of this study is using an anodizing intermediate layer to improve corrosion resistance and adhesion of hydroxyapatite coated AZ31 alloy for applications in biodegradable implants. An anodizing intermediate layer was formed on the surface of AZ31 substrate at various anodizing voltage of 10, 20, 30, and 40 V respectively by anodizing process. HAp was grow on the surface of AZ31 substrate at 90°C and pH solution of 7.5 by chemical solution treatment method for 2 h. The coated samples were evaluated their corrosion behavior by Electrochemical measurements and biodegradation behavior by immersion test in Hank's balanced salts solution (HBSS) for 28 days via amount of Mg2+ ion released. While, their adhesion strength were evaluated by pull-off method. The amount of Mg2+ ions released of the samples was quantified by the Inductively coupled plasma mass spectrometry. An anodizing intermediate layer was successfully synthesized at various voltages by anodizing process and HAp coatings were prepared by chemical solution treatment method. The corrosion rate of hydroxyapatite coated AZ31 alloy with an anodizing intermediate layer decreased 4.4 times, while adhesion strength increased about two times compared to the HAp coated AZ31 specimen without an anodizing layer and achieved ~14.70, ~6.92 MPa, respectively. After immersion test in HBSS, the adhesion strength of HAp/AZ31-HBSS-specimen decrease to 45% because of large corroded areas with depth holes of hundreds of micrometers. The slighter decrease in adhesion strength of HAp/30V/AZ31-HBSS-specimen to 22% is due to the contribution of the anodizing intermediate layer. HAp coated AZ31 alloy specimen with the existence of a porous structure with an elliptical shape, uniform and high density of MgO on the surface at anodizing voltage of 30 V resulted in a significant increase in corrosion resistance and the adhesion strength of HAp coatings.

Hydrothermal synthesis of LiMn0.79Fe0.2Mg0.01PO4/C composite cathode materials using different Li3PO4 precursors

Doping and particle size controlling are two important approaches to improve the electrochemical performance of LiMnxFe1−xPO4 cathode materials. By employing a straightforward hydrothermal method and utilizing cost-effective lithium phosphate (Li3PO4) as the precursor, we successfully synthesized high Mn-content LiMn0.79Fe0.2Mg0.01PO4/C composites. The results reveal that the minute amount of Mg substantially enhances the electrochemical performance. In the subsequent mechanism study using Li3PO4 precursors with different particle size, we found that the nucleation process, dependent on specific surface area and diffusion rate, is likely to play a critical role for the size and morphology of formed LiMn0.79Fe0.2Mg0.01PO4. LiMn0.79Fe0.2Mg0.01PO4/C (LMFP-1), synthesized from initially smaller-sized and less agglomerated Li3PO4 (LPO-1), exhibited the most diminutive average particle size coupled with the highest specific surface area, which further facilitated electrolyte interfacial interaction and promoted Li+ diffusion kinetics. At 1C, LMFP-1 displayed a specific capacity of 110.7 mAh g−1, with 97.07% capacity retention after 200 cycles. This study provides pivotal insights for the synthesis of high-performance LiMnxFe1−xPO4 materials.

Effects of Mg(II) doping amount on the hydration characteristics of kaolinite surface: Molecular dynamics simulations and experiments

To explore the microscopic effects of Mg(II) doping amount on the hydration characteristics of kaolinite surface, the Mg(II) ions and kaolinite were used as the subjects of research in molecular dynamics simulations and experimental verification to investigate the microscopic effects of the lattice magnesium impurity on the surface hydration of kaolinite. The results indicate that the interaction between H2O and Mg(II)-doped kaolinite (Mg(II)-Kao) surfaces, along with hydrogen bonding at the interface, gradually increase with increasing Mg(II) doping amounts, implying that Mg(II) doping significantly enhance the surface hydration of kaolinite. The hydration of the Mg(II)-doped kaolinite (001) surface (Mg(II)-Kao(001)) is stronger than that of the Mg(II)-doped kaolinite (001¯) surface (Mg(II)-Kao(001¯)) with the same Mg(II) doping amount. As the quantity of Mg(II) doping increased, the contact angle and humidity of the kaolinite surface decrease and progressively increase, respectively, signifying that the hydration level of the kaolinite surface increase. Overall, the main influence of Mg(II) doping on the surface hydration properties of kaolinite is the enhancement of hydration activity and ionic hydration. The results can provide theoretical support for further study of the real clay surface hydration mechanism, efficient treatment of clay-containing mineral processing wastewater and resource utilization of coal measure clay.

Rock magnetic analyses as a tool to investigate diversity of drift pumice clasts: An example from Japan's 2021 Fukutoku‐Oka‐no‐Ba (FOB) eruption

AbstractThe crystallization of nanolites within magma chambers has recently raised a strong interest due to their impact on increasing melt viscosity and triggering magmatic eruptions. In 2021, the Fukutoku‐Oka‐no‐Ba (FOB) underwater eruption produced large quantities of pumices that eventually formed rafts drifting at the surface of the ocean to the East coasts of Japan. Pumices collected along the shore shortly after grounding show various colors, microscopic and Raman analyses made by Yoshida et al. (Island Arc, 31, 1, 2022) revealed the presence of magnetite nanolites in some of them. In this study, we explore the magnetic properties of a batch of pumices of different colors from the FOB eruption, aiming to refine characterization of iron oxide nanolites. We used various analytical techniques such as SEM and FEG‐SEM observations, EDS‐X analyses, and rock magnetic experiments, including thermomagnetic analyses, hysteresis curves, coercivity analyses and FORC measurements. Our findings reveal that the iron oxides present in the FOB samples are Ti‐magnetite, with minor amounts of Mg and Al. The magnetic crystals show a wide range of sizes, from extra small iron oxide nanolites (ESION) in the pumices with the lighter colors, to more bulky grains reaching the micrometer size in some of the dark color samples, significant diffusion is inferred in that case. Consequently, the magnetic characterization of iron oxide crystals within the Fukutoku‐Oka‐no‐Ba pumices reveals varying stages of nucleation, dissolution, growth, and diffusion processes, providing evidences for the heterogeneous state of the magma during the eruption.

Determination of trace elements in ibuprofen drug products using microwave-assisted acid digestion and inductively coupled plasma-mass spectrometry

Trace elements are found in most drugs as a result of the drug formulation and drug production methods. An inductively coupled plasma-mass spectrometry method for the determination of 24 trace elements (Mg, Ti, V, Cr, Mn, Cu, Fe, Co, Ni, Zn, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, Sb, Ba, Ir, Pt, Au, and Pb) in solid ibuprofen tablets was established in relation to the ICH Q3D(R1) guideline, to evaluate the possibility of linking trace elemental profiles to drug formulation strategies, and to differentiate between drug products based on the trace elemental profiles. Ten European ibuprofen drug products were evaluated (n=3). The sample preparation was performed by microwave-assisted acid digestion using only 10 mg of homogenized sample and 900 μL of a mix of 65% HNO3, 37% HCl, and 30% H2O2. Solid residuals primarily composed of insoluble SiO2 excipients were removed by centrifugation. Only concentrations of Mg, Fe, Ti, Mn, Cr, and Ni were detected above the limits of detection and did not exceed the ICH Q3D(R1) guideline permitted daily exposure limits. The trace elemental profiles were evaluated through principal component analysis. Three principal components describing 96% of the variance were useful in grouping the ibuprofen drug products, and the detected trace elemental remnants could be related to drug formulation and drug production strategies. An in-house quality control material was used in lack of certified reference materials and was in combination with spike recoveries used for method validation. Good spike recoveries (94–119%) were obtained for all measured trace elements except Mg. Mg showed acceptable spike recoveries (75–155%) for mid and high-spike concentrations, but poor recoveries (30–223%) were detected with low spike concentrations in spike matrices containing high amounts of Mg. Overall, the method is suggested applicable for solid drugs containing insoluble SiO2 excipients and drugs comparable to ibuprofen.

Improved mechanical properties of SiC/SiC brazed joints via added Al in Si–Mg composite fillers

SiC components were joined under vacuum at 1100 °C for 10 min via Si–Mg composite fillers with added Al (XAl) ranging over 0–10 at.%. The joining mechanism involves Mg addition to Si, which lowers the melting point of Si. The transformation of the molten liquid phase into a solid Si layer is induced by Mg evaporation. In SiC/SiC joining, however, Mg evaporation was significantly suppressed when XAl = 0 at.%, with a large amount of Mg remaining in the joint, forming a brittle bonding layer of Si, Mg2Si, and MgO. Notably, Mg evaporation was enhanced by the addition of Al to the filler, resulting in the formation of a dense Si layer. The joint tensile strength increased with increasing XAl in the range of 0–6 at.% and then decreased with further increases in XAl. The changes in strength were correlated with microstructural changes in the bonding layer. From the microstructure and the phase diagrams, it was concluded that the added Al increased the thermodynamic degrees of freedom, which hindered the rate of Mg-evaporation-induced Si solidification from the liquid during joining. Because the amount of liquid surrounded and trapped by the solid Si decreased, more Mg in the liquid could diffuse to the surface.

Collagen membrane functionalized with magnesium oxide via room-temperature atomic layer deposition promotes osteopromotive and antimicrobial properties.

Artificial bone grafting materials such as collagen are gaining interest due to the ease of production and implantation. However, collagen must be supplemented with additional coating materials for improved osteointegration. Here, we report room-temperature atomic layer deposition (ALD) of MgO, a novel method to coat collagen membranes with MgO. Characterization techniques such as X-ray photoelectron spectroscopy, Raman spectroscopy, and electron beam dispersion mapping confirm the chemical nature of the film. Scanning electron and atomic force microscopies show the surface topography and morphology of the collagen fibers were not altered during the ALD of MgO. Slow release of magnesium ions promotes bone growth, and we show the deposited MgO film leaches trace amounts of Mg when incubated in phosphate-buffered saline at 37°C. The coated collagen membrane had a superhydrophilic surface immediately after the deposition of MgO. The film was not toxic to human cells and demonstrated antibacterial properties against bacterial biofilms. Furthermore, in vivo studies performed on calvaria rats showed MgO-coated membranes (200 and 500 ALD) elicit a higher inflammatory response, leading to an increase in angiogenesis and a greater bone formation, mainly for Col-MgO500, compared to uncoated collagen. Based on the characterization of the MgO film and in vitro and in vivo data, the MgO-coated collagen membranes are excellent candidates for guided bone regeneration.

Bioextraction of Magnesium as Plant Minerals from Magnesite Mine Wastes Collected from Salem District of Tamil Nadu, India

Magnesium (Mg) is an essential macronutrient that can be obtained through mineralization of mine spoils. The leftover mine spoils of magnesite mines still contain a reliable amount of Mg in it. The Mg present in raw magnesite spoils is in its carbonate form and hence it has to be mineralized to convert it into plant available soluble forms of Mg. The effect of B. cereus and B. stercoris in the mineralization of Mg has been studied in synthetic mineral salts medium (MSM). To obtain maximum mineralization results it is important to know the optimal conditions of the organisms under which they can grow and produce more Mg. The mineralizing capability of the individual organisms and their combined effect as a consortium under various concentrations of carbon source, pH, temperature and soil organic matter has been studied. It has been seen that the organisms grow and mineralize better when 1% of glucose has been supplemented as carbon source. The optimal pH and temperature were found to be pH 7 and 35°C, respectively. The addition of anthraquinone-2-sulphonic acid (ADQS) as soil organic matter enhances the mineralization Mg in synthetic medium. Rendering to SEM and EDX analysis, the mineralization of Mg in the synthetic medium was established.

Morphological, Structural, and Optical Features of Thermally Annealed Slag Powders Generated from the Iron and Steel Industry: A Source of Disordered Iron Oxide Composites

Steel slag waste produced by the steel industry accumulates in open areas or is disposed of in landfills, causing harm to the environment and human health. Valorizing steel slag through comprehensive data analysis is imperative and could add value to the product with respect to energy conversion and storage applications. This study investigated the morphological, structural, and optical characteristics of a thermally annealed steel slag composite generated from iron and steel factories. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, and UV–visible spectrophotometry were subsequently used to evaluate the impact of thermal treatment on the morphology, structure, elemental composition, and optical properties. It was found that the pre-treated slag composites contained a variety of irregular grain sizes and microscale fragments, primarily composed of C (18.55%), O (50.85%), and Fe (29.41%), with lower amounts of Mg (0.31%), Si (0.44%), and Ca (0.44%), indicating the natural formation of a disordered iron composite. Thermal treatment at different temperatures (300 °C, 600 °C, and 900 °C) increased the grain density and clustering, resulting in denser two-dimensional microstructures at 900 °C. Additionally, XRD and Raman analyses of both untreated and thermally treated slag composites revealed the presence of a disordered iron oxide composite, including (Fe3O4), hematite (α-Fe2O3), and maghemite (γ-Fe2O3) phases. A significant increase in optical absorbance was also observed after annealing at 600 °C, highlighting the successful optimization of the elemental composition of the slag composite. A band gap energy of approximately 2.2 eV was obtained from this optimization at 600 °C. The optical conductivity of the composite reached 2.1 × 106 S−1 at 600 °C, which indicates an enhancement in charge transfer among the optimized chemical elements in the waste composite. These findings suggest an optimization method for novel composites derived from steel slag waste, indicating its potential as a low-cost material for energy storage systems (batteries, supercapacitors, and fuel cells) and optoelectronic devices.

Antioxidant Properties of Chokeberry Products-Assessment of the Composition of Juices and Fibers.

Chokeberry fruits are a rich source of bioactive ingredients and their beneficial effect on the body has been proven in the literature. They contain antioxidants such as polyphenols (anthocyanins, procyanidins, phenolic acids, flavonols and flavanols) but also other essential substances with health-promoting potential, such as vitamin C and elements. Providing the right amount of these ingredients is very important for maintaining health and preventing the effects of oxidative stress. The aim of the study was to assess the content of antioxidant elements (magnesium-Mg) and trace elements (copper-Cu, iron-Fe, manganese-Mn, selenium-Se and zinc-Zn), with the antioxidant potential being measured using the FRAP method, along with total anthocyanin, total flavonoid and total polyphenol content (TPC) in 25 chokeberry juices and 6 chokeberry fibers sourced from conventional and organic farming. All chokeberry juices and chokeberry fibers available on the Polish market at that time were ordered for testing. The studied juices came from concentrate (FC) and not from concentrate (NFC). Taking into account the mineral content, it was shown that both chokeberry juices and fibers contained the highest amount of Mg and the lowest amount of Se. The FRAP value was significantly higher (p < 0.05) in organic juices compared to conventional ones as well as being higher (p < 0.05) in NFC juices compared to FC juices. NFC juices were also characterized by their higher concentrations of TPC, total flavonoid and total anthocyanin levels (p < 0.05) compared to FC juices. Consumption of 100 g of chokeberry juice can cover from 149.5 to 3177.0% of the daily requirement for Cu, 6.8-32.4% for Mn, 2.8-6.1% for Mg, 0.9-7.4% for Se, 0.2-3.7% for Fe, 0.3-1.2% for Zn and 8.3-34.5% for vitamin C. In turn, the consumption of 10 g of fiber can cover 4.3-32.0% of the daily requirement for Fe, 0.6-9.0% for Se, 3.7-8.2% for Cu, 2.2-3.8% for Mg, 0.6-9.0% for Se, 0.9-8.5% for Zn and 0.5-0.7%% for vitamin C. Chokeberry products can be a valuable component of a healthy diet.

Contribution to Knowledge on Bioapatites: Does Mg Level Reflect the Organic Matter and Water Contents of Enamel?

The matter constituting the enamels of four types of organisms was studied. The variability of the ions was presented in molar units. It was proven that the changes in water contents of the enamel are significantly positively related to changes in Mg; inversely, there is also a strong connection with changes in Ca and P, the main components of bioapatite. The variability in the organic matter has the same strong and positive characteristics and is also coupled with changes in Mg contents. Amelogenins in organic matter, which synthesize enamel rods, likely have a role in adjusting the amount of Mg, thus establishing the amount of organic matter and water in the whole enamel; this adjustment occurs through an unknown mechanism. Ca, P, Mg, and Cl ions, as well as organic matter and water, participate in the main circulation cycle of bioapatites. The selection of variations in the composition of bioapatite occurs only along particular trajectories, where the energy of transformation linearly depends on the following factors: changes in the crystallographic d parameter; the increase in the volume, V, of the crystallographic cell; the momentum transfer, which is indirectly expressed by ΔsinΘ value. To our knowledge, these findings are novel in the literature. The obtained results indicate the different chemical and crystallographic affinities of the enamels of selected animals to the human ones. This is essential when animal bioapatites are transformed into dentistic or medical substitutes for the hard tissues. Moreover, the role of Mg is shown to control the amount of water in the apatite and in detecting organic matter in the enamels.

Enhanced strength-conductivity trade-off in Al-Mg-Si alloys with optimized Mg/Si ratio

This study evaluated the potential for an enhanced strength–conductivity trade-off in Al-Mg-Si alloys with optimized Mg/Si ratios. In cases of the consistent total amounts of Mg and Si atoms, evident differences in hardness and conductivity manifested during artificial aging, contingent on the Mg/Si ratio investigated. The alloy with an Mg/Si ratio of 1.18 displayed a superior trade-off between strength and conductivity, yielding a yield strength of 305 MPa coupled with a remarkable conductivity of 51.57%IACS and 199.7 W/m/K. Alloys characterized by low Mg/Si ratios exhibited a significantly higher precipitates fraction than those with high Mg/Si ratios because of the accelerated age-precipitation kinetics. This resulted in the improved strength owing to the enhanced precipitation strengthening contribution. A constitutive model considering both fraction and structural composition of the precipitates was established to elucidate the mechanism of varying Mg/Si ratio on conductivity. Variations in the residual Mg and Si within the matrix have been demonstrated to predominantly account for the disparities in conductivity across alloys with distinct Mg/Si ratios. The substantial precipitation in the alloy with an Mg/Si ratio of 1.18 induced heightened depletion of both Mg and Si, consequently achieving a comparatively elevated conductivity concomitant with its relatively superior strength.

Alkali-silica reaction of high-magnesium nickel slag fine aggregate in alkali-activated ground granulated blast-furnace slag mortar

The construction industry is presently encountering a significant challenge regarding the shortage supply of natural sands. The use of metallurgical slags as fine aggregates in building materials presents a solution that not only mitigates the over-exploitation of natural sands, but also provides a sustainable and valuable approach for managing industrial solid wastes instead of traditional landfill disposal. This study investigated the alkali-silica reaction (ASR) of air-cooled and water-quenched high-magnesium nickel slag (HMNS) fine aggregates in alkali-activated ground granulated blast-furnace slag (AAS) mortars. The mortars exhibited satisfactory volume stability and structural integrity throughout the 120 days of accelerated mortar bar test. The lab-simulated dissolution test revealed the formation of a thin precipitate layer of sodium silicate hydrate on the surface of HMNS fine aggregates, which contained a significant amount of Mg with Mg/Si ratios ranging from 0.16 to 0.18. The divalent Mg cations were released from the HMNS fine aggregates and served as the pseudo network former to crosslink the ASR gel instead of Ca. This reduced the moisture adsorption capacity and mitigated the expansion of ASR gel.

Conversion of Surface Residual Alkali to Solid Electrolyte to Enable Na-Ion Full Cells with Robust Interfaces.

The deposition of volatilized Na+ on the surface of the cathode during sintering results in the formation of surface residual alkali (NaOH/Na2 CO3 NaHCO3 ) in layered cathode materials, leading to serious interfacial reactions and performance degradation. This phenomenon is particularly evident in O3-NaNi0.4 Cu0.1 Mn0.4 Ti0.1 O2 (NCMT). In this study, a strategy is proposed to transform waste into treasure by converting residual alkali into a solid electrolyte. Mg(CH3 COO)2 and H3 PO4 are reacted with surface residual alkali to generate the solid electrolyte NaMgPO4 on the surface of NCMT, which can be labeled as NaMgPO4@NaNi0.4 Cu0.1 Mn0.4 Ti0.1 O2 -X (NMP@NCMT-X, where X indicates the different amounts of Mg2+ and PO4 3- ). NaMgPO4 acts as a special ionic conductivity channel on the surface to improve the kinetics of the electrode reactions, remarkably improving the rate capability of the modified cathode at a high current density in the half-cell. Additionally, NMP@NCMT-2 enables a reversible phase transition from the P3 to OP2 phase in the charge-discharge process above 4.2V and achieves a high specific capacity of 157.3 mAh g-1 and outstanding capacity retention in the full cell. The strategy can effectively and reliably stabilize the interface and improve the performance of layered cathodes for Na-ion batteries (NIBs).

Solubility of 15MgO–15CaO–5P2O5–10SiO2 glass

AbstractMg2+ and silicate ions are important ionic species in bone formation. Previously, the authors’ group reported a 15MgO–15CaO–8P2O5–4SiO2 glass (silicophosphate invert glass [spIG]) containing orthophosphate and orthosilicate structures. Mg2+ and Ca2+ ions in the glass preferentially formed Si–O–Mg and P–O–Ca bonds, respectively, suppressing the release amount of silicate ions in a tris–HCl buffer solution (TBS). In this study, a new 15MgO–15CaO–5P2O5–10SiO2 invert glass without a silicate 3D‐network structure was prepared via a melt‐quenching method. The new glass exhibits an improved silicate‐ion release ability that promotes bone formation. The dissolution amounts of Ca2+ and phosphate ions from the glass into a TBS were similar to those of spIG, but the amounts of Mg2+ and silicate ions increased by ∼2 and ∼5 times, respectively. 31P and 29Si magic‐angle spinning nuclear magnetic resonance spectroscopic analyses showed that the glass was composed of orthophosphate and chain silicate structures. Even when the silica content exceeded that of spIG, the formation of a silicate 3D‐network was suppressed. The O1s X‐ray photoelectron spectra indicated that (Si, P)–O–Mg bonds contribute to the glass formation. In a glass model based on classical molecular dynamics, the oxygen coordination numbers of Mg and Ca were determined as 4–7 and 5–8, respectively. Mg2+ ions are predominantly responsible for bridging the silicate/phosphate structures in this glass and play an important role in tuning the glass formation and the release amount of silicate ions.