INCREASING THE PERFORMANCE OF STEEL PARTS BY COMPLEX SATURATION OF THE SURFACE WITH ALLOYING ELEMENTS

The change in the microstructure, hardness and thickness of diffusion coatings with varying content of boron carbide salts in the melt is studied. For samples made of U10 steel, the highest saturation capacity with the formation of a carbide layer is characteristic of a composition containing 2% BC, 5-6% alloying elements (Cr, V, Ti), 10% NaCl, the rest is borax NaBO. The addition of 3-5% aluminum oxide significantly increases the stability of the melt and contributes to the preservation of the saturating capacity. The technology of complex saturation of steel with alloying elements can be used to harden parts of stamping equipment and a wide range of tractor parts.

Relationships between hyperinsulinaemia, magnesium, vitamin D, thrombosis and COVID-19: rationale for clinical management

Risk factors for COVID-19 patients with poorer outcomes include pre-existing conditions: obesity, type 2 diabetes mellitus, cardiovascular disease (CVD), heart failure, hypertension, low oxygen saturation capacity, cancer, elevated: ferritin, C reactive protein (CRP) and D-dimer. A common denominator, hyperinsulinaemia, provides a plausible mechanism of action, underlying CVD, hypertension and strokes, all conditions typified with thrombi. The underlying science provides a theoretical management algorithm for the frontline practitioners.Vitamin D activation requires magnesium. Hyperinsulinaemia promotes: magnesium depletion via increased renal excretion, reduced intracellular levels, lowers vitamin D status via sequestration into adipocytes and hydroxylation activation inhibition. Hyperinsulinaemia mediates thrombi development via: fibrinolysis inhibition, anticoagulation production dysregulation, increasing reactive oxygen species, decreased antioxidant capacity via nicotinamide adenine dinucleotide depletion, haem oxidation and catabolism, producing carbon monoxide, increasing deep vein thrombosis risk and pulmonary emboli. Increased haem-synthesis demand upregulates carbon dioxide production, decreasing oxygen saturation capacity. Hyperinsulinaemia decreases cholesterol sulfurylation to cholesterol sulfate, as low vitamin D regulation due to magnesium depletion and/or vitamin D sequestration and/or diminished activation capacity decreases sulfotransferase enzyme SULT2B1b activity, consequently decreasing plasma membrane negative charge between red blood cells, platelets and endothelial cells, thus increasing agglutination and thrombosis.Patients with COVID-19 admitted with hyperglycaemia and/or hyperinsulinaemia should be placed on a restricted refined carbohydrate diet, with limited use of intravenous dextrose solutions. Degree/level of restriction is determined by serial testing of blood glucose, insulin and ketones. Supplemental magnesium, vitamin D and zinc should be administered. By implementing refined carbohydrate restriction, three primary risk factors, hyperinsulinaemia, hyperglycaemia and hypertension, that increase inflammation, coagulation and thrombosis risk are rapidly managed.

Selective Uptake of Ag(I) from Aqueous Solutions Using Ionic Liquid Modified Iron Oxide Nanoparticles

<a>Surface functionalized magnetic nanoparticles represent a potentially highly valuable tool for the selective recovery of metals from the aqueous phase, due to their ability to be manipulated and then recovered using an externally applied magnetic field. Ionic liquids are ideal candidates for such surface functionalization for a range of reasons, including their enhanced selectivity, low water consumption and high chemical stability. Herein the removal of Ag⁺ onto </a><a>[MTESPIm]⁺[Cl]⁻ on Fe₃O₄@SiO₂</a>as a function of pH, exposure time, nanosorbent concentration and type of stripping agent has been investigated. Ag⁺ removal was recorded to fit the Langmuir isotherm indicating monolayer formation, with a saturation capacity of 23.69 mg/g. Moreover, optimum conditions for the selective removal of Ag⁺ in preference to Cu²⁺ and Pb²⁺, were recorded at pH 3, exposure time ranging between 0-15 min and with the highest nanosorbent concentration tested (80 mg/10ml of adsorbate solution). In addition, the most efficient stripping agent for the sorbed Ag⁺ was determined to be thiourea at 0.6 M. Overall the results indicate that [MTESPIm]⁺[Cl]⁻ on Fe₃O₄@SiO₂is a highly adaptable and efficient agent for the selective recovery of Ag from the aqueous phase.

Selective Uptake of Ag(I) from Aqueous Solutions Using Ionic Liquid Modified Iron Oxide Nanoparticles

<a>Surface functionalized magnetic nanoparticles represent a potentially highly valuable tool for the selective recovery of metals from the aqueous phase, due to their ability to be manipulated and then recovered using an externally applied magnetic field. Ionic liquids are ideal candidates for such surface functionalization for a range of reasons, including their enhanced selectivity, low water consumption and high chemical stability. Herein the removal of Ag⁺ onto </a><a>[MTESPIm]⁺[Cl]⁻ on Fe₃O₄@SiO₂</a>as a function of pH, exposure time, nanosorbent concentration and type of stripping agent has been investigated. Ag⁺ removal was recorded to fit the Langmuir isotherm indicating monolayer formation, with a saturation capacity of 23.69 mg/g. Moreover, optimum conditions for the selective removal of Ag⁺ in preference to Cu²⁺ and Pb²⁺, were recorded at pH 3, exposure time ranging between 0-15 min and with the highest nanosorbent concentration tested (80 mg/10ml of adsorbate solution). In addition, the most efficient stripping agent for the sorbed Ag⁺ was determined to be thiourea at 0.6 M. Overall the results indicate that [MTESPIm]⁺[Cl]⁻ on Fe₃O₄@SiO₂is a highly adaptable and efficient agent for the selective recovery of Ag from the aqueous phase.

High-performance magnetic chicken bone-based biochar for efficient removal of rhodamine-B dye and tetracycline: competitive sorption analysis

Magnetic chicken bone-based biochar (MCBB) was successfully prepared and efficiently adsorbed rhodamine-B (RB) dye and tetracycline (TC) in multi-component systems. The magnetisation value, surface area, and pHpzc of the MCBB were found to be 66.5 emu/g, 328 m2/g, and 8.3, respectively. RB has higher saturation capacity (96.5 mg/g) and occupies more active sites on MCBB, thus limiting the sorption of TC with lower saturation capacity (63.3 mg/g). Langmuir isotherm suitably describes the sorption process in a single-component system; however, the multi-component system was well fitted to the Sheindorf–Rebhun–Sheintuch model. The selectivity factor values confirmed that MCBB had higher adsorption affinity toward RB than TC. The intraparticle diffusion model played a significant role in the sorption process. The MCBB can be easily desorbed with base-spiked H2O and reused without loss in stability or structural integrity.