Magnesium Composition Research Articles

Prediction of phases and mechanical properties of magnesium-based high-entropy alloys using machine learning

ObjectivesTo predict phases and mechanical properties of Mg-Al-Cu-Mn-Zn alloys and to validate the results. MethodsIn this study, 29 predictor features of the alloys were examined based on dataset drawn from relevant publications. The correlation of selected predictor features with mechanical properties of Mg-Al-Cu-Mn-Zn alloys were evaluated. New features specific to vehicle and aerospace applications were used. Feature selection schemes involving four machine learning (ML) classifiers that included artificial neural networks (ANN), linear discriminant analysis (LDA), random forest regression (RF) and k-nearest neighbours (k-NN) were adopted. Tensile test was carried out based on ASTM E8 standard. ResultsResults of correlation of features showed that specific strengths and specific modulus of the alloys were strongly and positively correlated with composition of alloying elements but strongly and negatively correlated with composition of magnesium. The results also revealed that homogenization temperatures and time were weakly correlated with the mechanical properties and phases while electronegativity difference and VEC had significant positive correlation. ANN was the best performing classifier followed by k-NN, LDA, and lastly RF with prediction accuracy on test data of 98.7%, 98.1%, 97.9% and 97.8%, respectively. The validity and applicability of the model was tested with three magnesium-based alloys: Mg-80-Al-10-Cu-5-Mn-5-Zn-0, Mg-80-Al-5-Cu-5-Mn-5-Zn-5 and Mg-91.2-Al-8.3-Cu-0-Mn-0.15-Zn-0.35 and compared with findings in literature. The model had higher prediction accuracies compared to previous ML models used on magnesium alloys. The model was then used to predict phases in the Mg-89.43-Al-8.16-Cu-0.34-Mn-0.25-Zn-1.81 alloy and it accurately predicted presence of Mg17Al12, Mg2Si, MgZn and MgZn2. Results of simulation in MatCalc version 6.04 also verified presence of the phases. The phases were further confirmed through SEM/EDS analysis.Conclusions.Dominant strengthening phases were Mg17Al12, Mg2Si, MgZn and MgZn2. Predicted yield strength, ultimate tensile strength and Young’s modulus were within the range of experimental results. Specific strengths and specific modulus were also within the range.

Deformation and melt–rock interaction in the upper mantle: Insights from the layered structure of the Horoman peridotite, Japan

To obtain a better understanding of melt–rock interactions in the upper mantle, microstructural and petrological analyses were conducted on deformed mantle peridotites from the Horoman peridotite complex, Hokkaido, Japan. The Horoman peridotite complex is lithologically heterogeneous and contains various kinds of ultramafic and mafic rocks. We studied an outcrop of 3 × 70 m in size that contains layered spinel harzburgite, plagioclase lherzolite, and mafic rocks. The results indicate that reactive melts migrated preferentially along the foliation in the already deformed peridotite, and that these melt-rich zones became especially prone to further deformation. This inference is supported by (1) the parallelism of the boundaries of rock layers and foliation in the deformed peridotite, and the shape and crystallographic preferred orientations (SPOs and CPOs) of olivine in the peridotites; (2) the diffusive trends of magnesium and modal compositions of pargasite grains near the boundaries between peridotite and mafic layers; (3) variations in the NiO content of olivine crystals; (4) variations in olivine CPOs with orthorhombic (010)[100] slip system patterns and weak fiber-[010] patterns; and (5) the strong pargasite SPOs, the cuspate shapes of the pargasites, and the absence of intercrystallite deformation. The results, combined with previously reported P–T conditions for the Horoman peridotite complex, indicate that the deformed peridotites and mafic rocks with a layered structure represent temperatures of 1050–1150 °C and pressures of 0.7–1.5 GPa. Our results suggest that a decrease in pressure led to the transition from a melt-free to a melt-bearing system with a consequent change in the deformation mechanism, from dislocation creep in the melt-free system to diffusion creep in the melt-bearing system, with strain localization in the fine-grained melt-rich layers. The change in deformation mechanism is likely to have occurred in the uppermost mantle beneath a mid-ocean ridge, where strong rheological contrasts are controlled by spatial variations in the melt fraction.

Effects of applied pressure on structural, electronic, and optical properties of magnesium incorporated wurtzite beryllium oxide at different magnesium compositions

The effects of applied pressure on the structural, electronic, and optical properties of magnesium-incorporated wurtzite beryllium oxide (w-BeO) at different magnesium compositions are calculated. Each compound at different applied pressures confirms stability in the wurtzite phase. At different applied pressures, the equilibrium lattice constants (a0, c0) increase, but the bulk modulus (B0) and the c0/a0 ratio decrease with increasing magnesium composition. With increasing pressure, the lattice constants of each specimen decrease nonlinearly. Each compound possesses a wide direct band gap (Г-Г) at different applied pressures. The calculated band gap decreases with increasing magnesium composition at different applied pressures. With an increase in applied pressure, the band gap of each compound increases. Each wurtzite specimen is optically anisotropic and exhibits birefringence. Electronic excitations from O-2p to Be-2s, 3p and Mg-3s, 3p are responsible for the various optical features of the considered alloys. At different applied pressures, static optical constants ε1(0), n(0), and R(0) increase, but critical points in the ε2(ω), k(ω, σ(ω), and α(ω) spectra decrease with increasing magnesium composition. For each specimen, components of static optical constants reduce, while components of critical point energies increase with an increase in applied pressure.

Spatially Resolved Assessment and Analysis of Al-Zn, Mg, and Mg/Al-Zn Metal-Rich Primers Applied to AA 7075-T651 in Full Immersion

The scanning vibrating electrode technique (SVET) was utilized to monitor localized corrosion and substrate protection of three metal-rich primers (MRP). The ability to suppress localized corrosion and provide widespread cathodic polarization to enable sacrificial anode-based cathodic protection of a AA 7075-T651 substrate with either an aluminum-rich primer (AlRP), magnesium-rich primer (MgRP), or a composite magnesium + aluminum-rich primer (MgAlRP) in a polyamide-based epoxy primer coatings fully immersed in 1 mM NaCl was investigated. Pigments did not activate uniformly in each MRP. The notion of throwing power polarizing the bare substrate and uniform current and potential distributions at scratch sites does not describe the behavior observed. In cases where activation occurred, protection was noticed in the form of suppression of local anodes on bare AA 7075-T651. Local corrosion was suppressed on heterogeneously corroding AA 7075-T651 with strong local anodes and cathodes. Widespread cathodic polarization was absent. The MgRP and MgAlRP were shown to provide superior local corrosion suppression associated with pitting on AA 7075-T651 compared to the AlRP.

ZnMgO Thin Films by Ultrasonic Spray Pyrolysis: Modulation of Optical and Electrical Properties by Post‐annealing and Magnesium Composition

ZnMgO semiconductor is of major interest in sustainable thin‐film solar cells in order to replace buffer layers based on nonabundant or toxic elements. In addition, it has the potential 1) to allow optimal band alignment with absorbers such as CIGS, CZTS, and Cu2O; 2) to have high transparency; 3) to have adjustable properties for use as a window or buffer layer; and 4) to be deposited using low‐cost and energy‐efficient techniques such as ultrasonic spray pyrolysis. This study focuses on modulating ZnMgO properties with the optimization of the ultrasonic spray pyrolysis and post‐annealing parameters. Optical transmission, X‐ray diffraction, and van der Pauw/Hall effect measurements are used to study the material properties. Thin films with a strong <002> preferred orientation are obtained with large crystallite size (42–80 nm), high transparency (>90%), a bandgap increase from 3.28 to 3.34 eV with magnesium composition and annealing, an optimal Urbach energy of 0.068 eV, and electrical properties modulated by magnesium composition and annealing with resistivity varying from 6.520 Ωcm down to 0.022 Ωcm and a carrier concentration from 4.8 × 1017 up to 1.4 × 1020 cm−3.

Sizeable net export of base cations from a Carpathian flysch catchment indicates their geogenic origin while the 26Mg/24Mg, 44Ca/40Ca and 87Sr/86Sr isotope ratios in runoff are indistinguishable from atmospheric input.

Nutrient imbalances may negatively affect the health status of forests exposed to multiple stress factors, including drought and bark beetle calamities. We studied the origin of base cations in runoff from a small Carpathian catchment underlain by base-poor flysch turbidites using magnesium (Mg), calcium (Ca) and strontium (Sr) isotope composition of 10 ecosystem compartments. Our objective was to constrain conclusions drawn from long-term hydrochemical monitoring of inputs and outputs. Annual export of Mg, Ca and Sr exceeds 5-to-15 times their atmospheric input. Mass budgets per se thus indicate sizeable net leaching of Mg, Ca and Sr from bedrock sandstones and claystones. Surprisingly, δ26Mg, δ44Ca and 87Sr/86Sr isotope ratios of runoff were practically identical to those of atmospheric deposition and soil water but significantly different from bedrock isotope ratios. We did not find any carbonates in the studied area as a hypothetical, easily dissolvable source of base cations whose isotope composition might corroborate the predominance of geogenic base cations in the runoff. Marine carbonates typically have lower δ26Mg and 87Sr/86Sr ratios, and silicate sediments often have higher δ26Mg and 87Sr/86Sr ratios than runoff at the study site. Mixing of these two sources, if confirmed, could reconcile the flux and isotope data.

Comparative Reports on Pleurotus Sajor-caju Cultivated on Local Wood Wastes in Ibadan Metropolis, Nigeria

Cultivation of Pleurotus species, an Oyster mushroom is now becoming well known due to its taste, medicinal and nutritional values. It is capable of degrading agricultural wastes efficiently and even grows at different temperature ranges. Relatively, Pleurotus species has shorter life span and the fruiting bodies are rarely attacked by pests and diseases unlike the other edible mushrooms. Therefore, the aim of this research is to access the influence of mineral constituents of five local wood wastes (Anogeissus leiocarpa, Pouteria altissima, Vitellaria paradoxa, Cordia milleni and Triplochiton scleroxylon) in Ibadan metropolis on the growth, fruiting body yield and proximate analysis of cultivated oyster mushroom (P. sajor-caju). Data of Carbon/Nitrogen ratio (11.10 – 11.60) found reveal composition of Magnesium (0.035 mg), Potassium (0.053 mEq/l), Manganese (0.0013 mg), Copper (0.00050 g/m3), Iron (0.00275 mol/L), Phosphorus (0.027 mmol/L), Organic carbon (32.10 mg/L C), Organic matter (55.3 t/ha) and total nitrogen (2.77 mg/L) contributed greatly to the high crude protein, fats and ash contents of mushroom cultivated on T. Scleroxylon. However, insignificant contents of sodium (0.2 mg), Calcium (0.2 mmol/L) and Magnesium (0.013 mg) in Pouteria altissima led to the general inadequate performance of (P. sajor-caju) in yields. The fresh mean weight of (P. sajor-caju) was from 8.00 g – 27.53 g. The heaviest weight was obtained from T. scleroxylon followed by V. paradoxa, C. milleni, while Anogeissus leiocarpa gave the lightest weight. Hence, T. scleroxylon will be suggested for cultivating P. sajor-caju because of its positive impact on the yield, crude fibre, and protein content of the experimented mushroom.

Proximate, Minerals and Vitamins Analyses of Some Common Foods in Nigeria

Nutritional composition is a key factor that must be considered in our daily choice of diets. Hence, the need for nutritional analysis of these five (5) common Nigerian solid foods (poundo yam, semovita, corn flour, cassava flour, and wheat flour). The flour samples were chemically analysed for proximate and Mineral elements: magnesium, iron, sodium and calcium composition, using the methods described by Association of Analytical chemist. Vitamin A content was determined by spectrophotometric method while Vitamin C content was determined using the spectrometric method coupled with DNPH procedures. The result revealed that Poundo yam had the highest carbohydrate content (82.695%) and least in the following parameters; moisture (7.55%), calcium (30.075mg), iron (9.20mg), sodium (15.565mg), and magnesium (26.185mg) among other samples. Semovita has the highest protein content (16.3%), vitamin A (0.52mg) and vitamin C (3.61mg). Wheat flour was rated highest in ash (1.82%) and sodium (25.3mg) contents respectively. It was also observed that wheat flour had the least content of vitamin A (0.09mg). Corn flour was highest in crude fat (5.5%). Cassava flour had the highest crude fibre (1.9%), calcium (228.55mg), iron (17.85mg) and magnesium (88.55mg), and turned out to be least in protein (1.025%) and vitamin C (0.44mg) content.

Chemical composition of natural waters from the Urov endemic area

Owing to the importance of drinking water in human nutrition, in this study, we performed a comparative analysis of the chemical composition of drinking water from settlements endemic to Kashin–Beck disease and from territories that are not endemic to Kashin–Beck disease. Our analysis showed that all drinking water samples were weakly alkaline and had a hydrocarbonate–calcium–magnesium composition. There were no considerable differences in mineralization, pH, or concentrations of Mg, Si, F, Se Zn, K, and Na. All waters had weak hardness specific for the waters from the northern territories. The mineral waters from the Urov biogeochemical subregion of the biosphere have elevated concentrations of Ca, Mg, Sr, Si, and Li and lower concentrations of I, Se, and Cu. The maximum Sr content was found in mineral water from the Bazanovo village, i.e., 20 mg/L, with a Ca/Sr ratio of 8 units. Owing to the inconsistency of data on the chemical composition of drinking water from the territories endemic for Kashin–Beck disease, we suggest an indirect role of biogeochemical factors in the disease pathogenesis. Previous pathologies may be important, which have arisen because of hypothermia, common cold, hormonal imbalance, and alimentary factors.

Deterioration of structural integrity and ferromagnetic transformation due to the emergence of traces of Alpha-hematite (α-Fe2O3) secondary phase in magnesia-enriched nickel ferrite spinel nanoparticles

MgNi ferrite nanoparticles were prepared successfully via wet sol-gel route using the nitrates of proposed elements i.e. Mg, Ni and iron were used as precursors with citric acid as fuel. The prepared materials were annealed at a temperature of 900∘C to achieve the best properties. To know structural, morphological, elastic and magnetic properties, the synthesized nanoparticles were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscope (HRTEM), vibrating sample magnetometer (VSM), FTIR spectroscopy and Raman spectroscopy. The results of XRD, FTIR and Raman spectroscopy patterns are indicative of formation of ferrite nanoparticles and the structural studies confirm the inverse-spinel structure with crystallite size 35–61 nm. The formation of spinel ferrite structure is confirmed by absorption bands corresponds to vibration of tetrahedral site-A and by absorption bands corresponds to the octahedral site-B. Crystallite size calculations were carried out using WilliamFson-Hall plot. Rietveld refinement was applied to assure the crystal structure and allied parameters. The magnetic analysis of the prepared samples was carried out by VSM indicates that the nanoparticles exhibited superparamagnetic behavior having high magnetic saturation (MS) and negligible coercivity (HC). The elastic and magnetic properties through absorption bands found degraded at higher magnesium compositions.

Efficacy and Tolerability Evaluation of a Nutraceutical Composition Containing Vitex agnus-castus Extract (EVX40™), Pyridoxine, and Magnesium in Premenstrual Syndrome: A Real-World, Interventional, Comparative Study.

Background Pre-menstrual syndrome (PMS) is a condition associated with altered hormone levels during the menstrual phase of females and is characterised by physical, emotional, and behavioural symptoms that have a negative impact on the quality of life of females. The symptoms of PMS may vary between individuals, but the major complication is pain, especially during menstrual days. The current treatment strategy involves the use of hormonal therapies and analgesics for symptomatic relief, but these therapies have a risk of potential side effects. The use of herbal and nutraceutical supplements in PMS conditions is increasing due to their long-term safety and proven efficacy. The current real-world study aimed to evaluate the efficacy and tolerability of Ezedayz® tablets containing Vitex agnus-castus extract (EVX40™), vitamin B6, and magnesium in PMS subjects. Methodology A real-world, open-label study was conducted involving 64 participants with varied severity of PMS symptoms. Participants were categorised into Group A (N=23) receiving standard therapies, Group B (N=20) receiving Ezedayz®tablets, or Group C (N=21) receiving standard and Ezedayz®therapy. Standard therapies were provided as per physician supervision, and Ezedayz® tablets were given for 90 days. All subjects were evaluated on core symptoms of PMS like menstrual backache, menstrual cramps, joint or muscle pain, and headache using the numerical rating scale (NRS), and quality-of-life (QoL) was evaluated using a QoL questionnaire. A spontaneous reporting methodology was used to evaluate the tolerability of the therapies provided. Statistical analysis was performed as per the statistical plan. A p-value of <0.05 was considered statistically significant. Results Out of 64 participants, five were lost to follow-up, and the data of 59 participants were included in the final analysis. All groups showed improvement in all evaluated parameters, but Group B and Group C showed greater improvement at the end of the study in all evaluated parameters. The quality-of-life assessment revealed greater improvement in Group B and Group C participants compared to Group C in all evaluated QoL parameters. No serious side effects were observed in any subjects. Conclusion The results of the current study conclude that the nutraceutical composition of Vitex agnus-castus extract, vitamin B6, and magnesium is effective in reducing the severity of PMS symptoms and improving the quality of life of PMS subjects. The nutraceutical therapy provided greater relief from PMS symptoms compared to standard therapy alone, and this effect was augmented when the nutraceutical therapy was provided in combination with standard therapies. Similarly, the improvement in quality-of-life parameters was greater in subjects treated with nutraceuticals alone or in combination therapy. Despite the limitations of the study, the results of the current study are promising, and the nutraceutical composition (Ezedayz®) can be effectively used in clinical settings to control symptoms and improve the quality of life of PMS patients.

Effects of Mineral Composition of Different Wood Wastes in Ibadan on Proximate Composition of Lentinus Squarrosulus (Mont.)

Lentinus squarrosulu (Mont.) is one of the cultivated indigenous edible mushrooms that are available in Nigeria. Recently, there has been growing crave to crop wild edible mushroom species that have potential economic values. Mushrooms can be an alternative source of protein especially for commoners in the society. Hence, the objective of this paper is to evaluate the effect of mineral composition of five wood wastes- Triplochiton scleroxylon, Cordia milleni, Vitellaria paradoxa, Pouteria altissima and Anogeissus leiocarpa different wood wastes on L. squarrosulus (Edible Mushroom) cultivation for their consequences on the growth, yield and proximate analysis. Data obtained reveal Carbon/Nitrogen ratio of 11.59, composition of Magnesium (0.035 mg), Potassium (0.053 mEq/l), Manganese (0.0013 mg), Copper (0.00050 g/m3), Iron (0.00275 mol/L), Phosphorus (0.027 mmol/L), Organic carbon (32.10 mg/L C), Organic matter (55.3 t/ha) and total nitrogen (2.77 mg/L) contributed greatly to the high crude protein, fats and ash contents of mushroom cultivated on T. Scleroxylon. However, insignificant contents of sodium (0.2 mg), Calcium (0.2 mmol/L) and Magnesium (0.013 mg) in Pouteria altissima led to the general inadequate performance of L. squarrosulus in yields. The percentage fresh mean weight of L. squarrosulus ranged from 9.13 g – 19.00 g. The highest value was produced by T. scleroxylon followed by P. altissima, V. paradoxa, C. milleni while A. leiocarpa gave the least.

Influence of severe drought on mineral nutrient status in eastern white pine (Pinus strobus L)

The photochemical process of photosynthesis is significantly influenced by the availability of nutrients. The purpose of this research is to ascertain how photosynthetic pigment function is affected by nutrient elemental changes caused by severe drought stress. Using elemental analysis, we looked at the changes in mineral nutrient composition in eastern white pine (Pinus strobus L) seedlings 32 days after drought treatment. According to our findings, severe drought resulted in a significant and non-significant decrease in the contents of Chl “b and a”, respectively. The elemental composition of iron (Fe), zinc (Zn), magnesium (Mg), potassium (K), phosphorus (P) and nitrogen (N) was measured. After severe drought treatment, leaf nutrient status showed a significant decline in total N (control-1.57 ± 0.1; drought-0.65 ± 0.07), P (control-959.4 ± 17; drought-645 ± 46), Mg (control-1030.4 ± 33; drought-750.7 ± 76), and K (control-3062.5 ± 32; drought-1853.3 ± 198), with a non-significant decrease in leaf Fe (control-120.3 ± 20; drought-98.9 ± 28) and increase in leaf Zn (control-33.49 ± 2; drought-39.05 ± 4). A positive correlation was found between the content of Fe, P, Mg, K, and N in leaf Chl “b”, but only a positive correlation was found between the content of Zn in leaf Chl “a” during severe drought. During severe drought, nutrient reallocation has a significant impact on leaf chlorophyll levels, as evidenced by this correlation.

Properties of Cosmic-Ray Sulfur and Determination of the Composition of Primary Cosmic-Ray Carbon, Neon, Magnesium, and Sulfur: Ten-Year Results from the Alpha Magnetic Spectrometer.

We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.

In situ oxygen, magnesium, and silicon isotopic compositions of the FUN inclusion Vigarano 1623‐5

AbstractOxygen, magnesium, and silicon isotopic abundances in Vigarano 1623‐5 were studied using secondary ion mass spectrometry to investigate correlations between isotopic and petrologic properties of this unique forsterite‐bearing FUN inclusion. Vigarano 1623‐5 displays large, correlated mass‐dependent fractionation effects, tightly linked to mineralogy within distinct petrologic units of the inclusion. The pyroxene‐rich and melilite‐rich interior parts of the inclusion display highly mass‐fractionated isotopic compositions of oxygen, magnesium, and silicon, consistent with Rayleigh distillation during evaporation of a melt with initial oxygen composition close to a solar composition. However, the chemical composition, enriched in magnesium and silicon, suggests a precursor already fractionated by prior melt evaporation. A discontinuous igneous rim was produced by a flash‐melting event followed by isotopic exchange in the rim melilite with planetary‐like oxygen, mechanical fragmentation, and reassembly with an accretionary rim of heterogeneous materials. Al‐rich minerals in 1623‐5 show evidence for having crystallized with live 26Al but at less than the “canonical” level of most CV calcium‐aluminum‐rich inclusions. However, well‐defined 26Al‐26Mg isochrons are not found and temporal implications are ambiguous.

Evaluation of the Phytochemical and Proximate Composition of Fruit of False Yam (Icacina senegalensis) and African Star Apple (Chrysophyllum albidum)

The biochemical composition of the seed, fruit-pulp and fruit-skin of false yam and African star apple was carried out in this study using standard techniques. The result of the mean phytochemical composition of Icacina senegalensis and Chrysophyllum albidum fruits revealed higher composition of tannin in the pulp, seed of I. senegalensis, while alkaloid and flavonoid was higher in composition in the pulp (24.22±0.141mg/100g and 16.53±0.021mg/100g), seed (25.35± 0.021mg/100g and 18.27±0.014mg/100g)and bark (24.62±0.085mg/100g and 16.94± 0.035 mg/100g) of Chrysophyllum albidum. The results were significantly different at p&lt;0.05. The result of the percentage proximate composition of Icacina senegalensis and Chrysophyllum albidum fruits revealed higher percentage composition of carbohydrate in the pulp (51.52±0.127% and 57.02±0.141%), seed (52.42±0.085% and 56.1±0.198%) and bark (54.89±0.092% and 58.02±0.113%) of I. senegalensis and C. albidum. The result revealed high percentage composition of fat in the pulp (26.33±0.028% and 9.63±0.028%), seed (25.69±0.014% and 10.24±0.035%) and bark (23.14±0.028% and 9.28±0.071%) of I. senegalensis and C. albidum respectively. Moisture content was also high in the pulp (12.37±0.014% and 8.35±0.042%), seed (11.45±0.021% and 7.36±0.042%) and bark (11.13±0.014% and 5.23±0.028%) of I. senegalensis and C. albidum respectively. The result of the mean mineral composition of Icacina senegalensis and Chrysophyllum albidum fruits revealed high composition of calcium in the pulp, seed and bark of I. senegalensis and C. albidum respectively. The result also revealed high composition of magnesium in the pulp, seed and bark of I. senegalensis and C. albidum. The results from this work suggest that Icacina senegalensis and Chrysophyllum albidum may find their use in food/feed formulation/supplementation as well as nutraceutical/medicinal and industrial uses.

Potassium, sodium, calcium and magnesium levels of commonly consumed foods and estimates of dietary intakes of selected Nigerian adults

Micronutrient deficiency is a public health challenge globally, as it affects both people and the economy. In Nigeria, most micronutrients, especially minerals are lost during food processing. The study was carried out to determine the potassium, sodium, calcium and magnesium composition of foods commonly eaten by Nigerian adults and to estimate the average adults' daily intake of these macrominerals. The contents of these minerals in 141 food items collected ‘as consumed’ from 10 locations in Federal Capital Territory, Abuja and Ogun State, Nigeria, were quantified by digesting the foods through dry ashing and analysed using flame atomic absorption spectrometer. The levels (mg/100 g fresh weight) of potassium, sodium, calcium and magnesium in the various foods ranged from 2.92 to 1520, 1.46 to 30,700, 1.35 to 1280 and 1.16 to 416, respectively. Recovery values were within the range of 95–110%. Adults' mean mineral intakes (mg/person/day) of the analysed foods were 1970 ± 780, 2750 ± 1100, 423 ± 300 and 389 ± 130 for potassium, sodium, calcium and magnesium, respectively. Mean sodium intake was higher while potassium and calcium intakes were lower compared with international recommendations (mg/person/day) of 1500, 2300–3400 and 1000–1300, respectively; indicating the need to enlighten consumers. The snapshot data from this study are useful to update the Nigerian Food Composition Database.

Оценка воспламеняемости дисперсных компонентов отходов горнодобывающей промышленности

Waste dumps are the man-made wastes of the mining industry. Particles of magnesium and aluminum are part of waste dumps and emissions from their combustion. Release of the dispersed particles of these metals leads to the spread of fire on the surface of the waste dump and beyond. Assessment of the dispersed composition of magnesium and aluminum particles, their flammability and the induction period allow to predict the fire hazard of rock dumps and the surrounding area. This contributes to ensuring the environmental safety of mining agglomerations. The most probable particle sizes of its oxide were established by sedimentation analysis of metallic magnesium scale. It was experimentally determined that the maximum temperature, at which magnesium particles of any fraction do not ignite, is 983 K. When the temperature reaches 1053 K, ignition of magnesium particles of all the rock dump fractions occurs, and at 1243 K, aluminum particles. The induction period for magnesium particles 1∙10–4 m in size at a temperature of 1053 K is 0,057 s. With increasing temperature, it decreases linearly. It is established that with an increase in temperature, the particles of the fraction 4,9∙10–5 m are the first to burn. The last to flash are the smallest particles of 6∙10–6 m. During research it was found that at the fixed particle sizes, an increase in temperature leads to a rapid reduction in the induction period. Its drop is observed at temperatures close to the flammability temperatures of the particles. An increase in the mass of magnesium particles leads to an increase in the induction period.

Синтез трехкомпонентного сплава на основе алюминия методом селективного лазерного плавления

Introduction. The technology of selective laser melting is one of the key technologies in Industry 4.0, which allows manufacturing products of any complex geometric shape, reducing significantly the amount of material used, reducing the lead time and obtaining a new alloy from elementary powders in the melting process. To understand the process of alloy formation under laser exposure, it is necessary to know the initial data of powders, which significantly affect the quality of the products obtained. The purpose of this study is to determine the requirements for the structural-phase state, elemental composition of aluminum, silicon and magnesium powders and further preparation of Al-Si-Mg (Al — 91 wt.%, Si — 8 wt.%, Mg — 1 wt.%) powder mixture for laser synthesis. The initial powders of aluminum PA-4 (GOST 6058-73), silicon (GOST 2169-69) and magnesium MPF-4 (GOST 6001-79) and powder composition Al-Si-Mg are studied using X-ray diffraction and X-ray phase analysis. The shape and sizes of particles are determined by the studies of raster electronic images. By the method of selective laser melting, samples are obtained from a powder composition under constant and pulsed laser exposure. The composition is prepared by mixing powders in a globe mill. Results and discussion. It is shown that the initial powders of aluminum, silicon and magnesium are single-phase. Particles with a size of 20–64 µm, recommended for selective laser melting, are used to obtain a powder composition. By mixing the powders for one hour, spherical particles are obtained, which is preferable for laser melting. The results of grinding the samples after laser melting showed that the samples obtained under constant laser exposure at the following mode parameters: P = 80 W, V = 300 mm/s, s = 90 μm, h = 25 μm have the greatest mechanical strength. Conclusions. The described study shows the possibility of synthesizing products from a powder composition of aluminum, silicon and magnesium by selective laser melting.

HARDNESS AND CORROSION BEHAVIOR OF Ti-20Cu-20Ni-20Mn- 20Zn AS HIGH ENTROPY ALLOY AND TI-13Cu-9Ni-5Mn-5Zn FOR MARINE STRUCTURE APPLICATION

An aneurysm clip is an implant tool for assisting the neurosurgeon in treating acute hemorrhagic stroke and cerebral aneurysm. This equipment stops the blood flow of a ruptured or enlarged blood vessel or aneurysm. In the development of aneurysm clip production, titanium alloy is the most used material selection. Several researchers reported that this metal leads to artifacts during MR (magnetic resonance) or CT (computed tomography) imaging. Since several pieces of evidence polyurethane could be a good material selection for aneurysm clips, this paper aims to investigate the material properties of the polyurethane foam with an additional combination of magnesium and zinc. This study conducts magnesium and zinc composition variations of 1 wt.%, 2 wt.%, and 3 wt.%, respectively. The materials were tested using a compression test, a FTIR (fourier-transform-infrared), SEM (scanning-electron-microscope), DSC (differential-scanning-calorimetry), and TGA (thermogravimetric-analyzer) to determine the material properties. From all examinations, adding magnesium and zinc to polyurethane foam affected the compressive strength and porosity of the polyurethane foam. Therefore, all test results concluded that adding magnesium with a composition of 3wt.%, which has a compressive strength of 0.84 MPa, is the best mixture. The idea of finding other compositions that are compatible with the polyurethane will significantly increase the possibility of new materials for aneurysm clip construction.