Salt Solution Research Articles

Ionic Strength-Induced Compartmentalization for Nanogel-in-Microgel Colloids.

Compartmentalization is crucial for control over complex biological cascade reactions. In microgels, the formation of discrete compartments allows for simultaneous uptake and orthogonal release of physicochemically distinct drugs, among others. However, many state-of-the-art approaches yielding compartmentalized microgels require the use of specific, though not always biocompatible, components and temperatures well above the physiological range, which may damage possible biological cargo. Therefore, a novel technique to fabricate compartmentalized microgels by exploiting ionic strength-induced precipitation as a mechanism for compartmentalization is developed. For this, a droplet-based microfluidic approach in which preformed nanogels are incorporated into poly(N-isopropylacrylamide)- or poly(acrylamide)-based microgels is employed. Allowing contact between the nanogel-monomer mixture and a salt solution only at the cross junction inhibits premature precipitation of the nanogels and aggregates form on the chip. It is demonstrated that this method is applicable to a variety of nanogel species in both stimuli-responsive and non-stimuli-responsive microgel networks. For temperature-responsive nanogel compartments in non-responsive microgels, anisotropic shape change is investigated by adjusting temperature or salt concentration or changing the solvent. Lastly, an exemplary uptake and release experiment demonstrates highly selective drug absorption, paving the way for more advanced biomimetic polymer structures.

Effects of Dexpanthenol on Corneal Neovascularization and Inflammation on Rat Model.

To evaluate the effect of subconjunctival injection of dexpanthenol on corneal neovascularization and inflammation in rats with induced chemical burns. This experimental study included 40 female albino Wistar rats. Chemical burns were induced in the right eye of all rats on the first day, and the left eye was used as a control. Rats were randomly divided into 5 groups. The no-treatment group (group 1) received no injections. Balanced salt solution injection in the sham group (group 2), dexpanthenol injection in the dexpanthenol group (group 3), bevacizumab injection in the bevacizumab group (group 4), and combined dexpanthenol and bevacizumab injection in the combined group (group 5) were administered subconjunctivally on day 7. The right corneas of all rats were photographed on days 7 and 14 to evaluate corneal neovascularization. The 2 corneal images were compared, and the differences were analyzed. All rats were euthanized, and the corneas were isolated. The levels of tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor-A, malondialdehyde (MDA), apoptosis, reduced glutathione (GSH), and total oxidant status were measured in rat corneas. Dexpanthenol reduced corneal neovascularization, and the difference was significant compared with the no-treatment and sham groups (P < 0.05). No significant difference in corneal neovascularization was observed between the dexpanthenol and bevacizumab groups. Dexpanthenol had a significant positive effect on vascular endothelial growth factor-A, TNF-α, total oxidant status, MDA, and GSH levels compared with the sham group (P < 0.05). Dexpanthenol may help control corneal neovascularization and inflammation after chemical burns.

Operational properties of cement-free concrete with porous aggregate

The article presents the results of technology development and research on the operational properties of porous aggregate and cement-free concretes based on it. The purpose of the work is to study lightweight concretes containing a liquid–glass porous aggregate for resistance to various aggressive influences. The porous granular aggregate was obtained by firing a mixture of liquid glass with the ash of thermal power plants and an ash aluminosilicate microsphere. Binders based on caustic magnesite and liquid glass with the addition of thermal energy waste were used to produce coarse-pored concretes. The choice of cement-free binders is due to the high adhesion to the filler. The behavior of the developed concretes in various aggressive environments, under the influence of low and elevated temperatures, has been studied. The resistance of magnesia concrete to the effects of water and salt solutions has been revealed. The technological and operational advantages of liquid-glazed concrete are shown, featuring increased thermal insulation ability, satisfactory resistance to aggressive media and resistance to low and high-temperature fluctuations. The developed concretes can be used in the enclosing structures of objects for various purposes.

The ER protein CANX (calnexin)-mediated autophagy protects against alzheimer disease

ABSTRACT Although the relationship between macroautophagy/autophagy and Alzheimer disease (AD) is widely studied, the underlying mechanisms are poorly understood, especially the regulatory role of the initiation signaling of autophagy on AD. Here, we find that the ER transmembrane protein CANX (calnexin) is a novel interaction partner of the autophagy-inducing kinase ULK1 and is required for ULK1 recruitment to the ER under basal or starved conditions. Loss of CANX results in the inactivity of ULK1 kinase and inhibits autophagy flux. In the brains of people with AD and APP-PSEN1 mice, the interaction of CANX and ULK1 declines. In mice, the lack of CANX in hippocampal neurons causes the accumulation of autophagy receptors and neuron damage, which affects the cognitive function of C57BL/6 mice. Conversely, overexpression of CANX in hippocampal neurons enhances autophagy flux and partially contributes to improving cognitive function of APP-PSEN1 mice, but not the CANX variant lacking the interaction domain with ULK1. These findings reveal a novel role of CANX in autophagy activity and cognitive function by cooperating with ULK1. Abbreviation: AD: Alzheimer disease; APEX: ascorbate peroxidase; APP: amyloid beta precursor protein; APP-PSEN1 mice: amyloid beta precursor protein-presenilin 1 transgenic mice; ATG: autophagy related; Aβ: amyloid-β; BiFC: bimolecular fluorescence complementation; CANX: calnexin; EBSS: Earle’s balanced salt solution; EM: electron microscopy; IP: immunopurification; KO: knockout; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MWM: Morris water maze; PLA: proximity ligation assay; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; SQSTM1/p62, sequestosome 1.

Phase Equilibrium of CO2 Hydrate with Rubidium Chloride Aqueous Solution

Salt lakes are a rich source of metals used in various fields. Rubidium is found in small amounts in salt lakes, but extraction technology on an industrial scale has not been developed completely. Clathrate hydrates are crystalline compounds formed by the encapsulation of guest molecules in cage-like structures made of water molecules. One of the most important properties for engineering practices of hydrate-based technologies is the comprehension of the phase equilibrium conditions. Phase equilibrium conditions of CO2 hydrate in rubidium chloride aqueous solution with mass fractions of 0.05, 0.10, 0.15 and 0.20 were experimentally investigated in the pressure range from 1.27 MPa to 3.53 MPa, and the temperature was from 268.7 K to 280.6 K. The measured equilibrium temperature in this study decreased roughly in proportion to the concentration of the RbCl solution from the pure water system. This depression is due to the lowering of the chemical potential of water in the liquid phase by the dissolution of RbCl. Experimental results compared with other salt solution + CO2 hydrate systems showed that the equilibrium temperatures decreased to a similar degree for similar mole fractions.

Evaporation Kinetics and Final Particle Morphology of Multicomponent Salt Solution Droplets.

In both nature and industry, aerosol droplets contain complex mixtures of solutes, which in many cases include multiple inorganic components. Understanding the drying kinetics of these droplets and the impact on resultant particle morphology is essential for a variety of applications including improving inhalable drugs, mitigating disease transmission, and developing more accurate climate models. However, the previous literature has only focused on the relationship between drying kinetics and particle morphology for aerosol droplets containing a single nonvolatile component. Here we investigate the drying kinetics of NaCl-(NH4)2SO4, NaCl-NH4NO3, and NaCl-CaCl2 mixed salt aqueous aerosol droplets (25-35 μm radius) and the resulting morphology and composition of the dried microparticles. A comparative kinetics electrodynamic balance was used to measure evaporation profiles for each mixed salt aerosol at a range of relative humidities (RH) (0-50% RH); measurements of the evaporation kinetics are shown to be consistent with predictions from the "Single Aerosol Drying Kinetics and Trajectories" model. Populations of the mixed salt droplets were dried in a falling droplet column under different RH conditions and imaged using scanning electron microscopy to observe the impact of the drying kinetics on the morphology. Energy dispersive spectroscopy was used in tandem to obtain atomic maps and view the impact of drying kinetics on the composition of the resultant particles. It has been shown that the relationship between drying kinetics and dry particle morphology in mixed salt solution droplets is compositionally dependent and determined by the predominant salts that crystallize (i.e., (NH4)2SO4, Na2SO4, or NaCl). The degree of homogeneity in composition throughout the particle microstructure is dependent on the drying rate.

Nonreceptor tyrosine kinase ABL1 regulates lysosomal acidification by phosphorylating the ATP6V1B2 subunit of the vacuolar-type H+-ATPase

ABSTRACT The vacuolar-type H+-ATPase (V-ATPase) is a proton pump responsible for controlling the intracellular and extracellular pH of cells. Its activity and assembly are tightly controlled by multiple pathways, of which phosphorylation-mediated regulation is poorly understood. In this report, we show that in response to starvation stimuli, the nonreceptor tyrosine kinase ABL1 directly interacts with ATP6V1B2, a subunit of the V1 domain of the V-ATPase, and phosphorylates ATP6V1B2 at Y68. Y68 phosphorylation in ATP6V1B2 facilitates the recruitment of the ATP6V1D subunit into the V1 subcomplex of V-ATPase, therefore potentiating the assembly of the V1 subcomplex with the membrane-embedded V0 subcomplex to form the integrated functional V-ATPase. ABL1 inhibition or depletion impairs V-ATPase assembly and lysosomal acidification, resulting in an increased lysosomal pH, a decreased lysosomal hydrolase activity, and consequently, the suppressed degradation of lumenal cargo during macroautophagy/autophagy. Consistently, the efficient removal of damaged mitochondrial residues during mitophagy is also impeded by ABL1 deficiency. Our findings suggest that ABL1 is a crucial autophagy regulator that maintains the adequate lysosomal acidification required for both physiological conditions and stress responses. Abbreviation: ANOVA: analysis of variance; Baf A1: bafilomycin A1; CCCP: carbonyl cyanide 3-chlorophenylhydrazone; CRK: CRK proto-oncogene, adaptor protein; CTSD: cathepsin D; DMSO: dimethylsulfoxide; EBSS: Earle’s balanced salt solution; FITC: fluorescein isothiocyanate; GFP: green fluorescent protein; GST: glutathione S-transferase; LAMP2: lysosomal associated membrane protein 2; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTORC1: mechanistic target of rapamycin kinase complex 1; PD: Parkinson disease; PLA: proximity ligation assay; RFP: red fluorescent protein; WT: wild-type.

Use of a Novel Steerable Tip Suction Cannula in Large and Giant Pituitary Adenomas: A Cadaveric Feasibility Study.

The endoscopic transsphenoidal approach is commonly used for sellar and suprasellar pathologies. However, reaching above the diaphragma sella, especially for posterosuperior and retrocavernous orientation, still poses some challenges. We designed and developed a steerable tip suction cannula (STSC) that has distinct leverage for endoscopic resection of such pathologies. The entire suction cannula is made of stainless steel. The instrument consists of a handle, vacuum tube, suction tip bed, suction tip, finger knuckle, wire path, countersunk headpin, and isolated steel wire. The working principle of the product is to enable the surgeon to move the aspiration tip in the desired direction by steering the finger knuckle. Five cadaveric specimens fixed with the saturated salt solution were used to evaluate the instrument and obtain measurements. In the straight position, the STSC aspirated 2.67% slower than the control aspirator tip and 13.24% faster than that at 30° angulation. Based on the CT measurements, the mean angulation of the instrument from the frontobasal axis was 38.3°. The mean distance from the frontobasal axis was 1.3cm. The average angulation of the tip of the instrument in the cranium was 25.5°. The designed STSC might effectively resect large to giant pituitary adenomas, especially those with supradiaphragmatic extension. Its suction capability is comparable to that of conventional suction tubes.

Molecular Dynamics Simulation Study on Heterogeneous Structure, Rheology, and Dynamic Correlation of Concentrated Aqueous Solutions of a Lithium Salt.

Molecular dynamics simulation of an aqueous solution of lithium bis(trifluoromethanesulfonyl)amide, LiTFSA, was performed at various concentrations to relate its liquid structure with frequency-dependent shear viscosity. The structure factor exhibited a low-q peak that represents a heterogeneous structure composed of water and anion domains, and the lithium ion existed in the water domain due to its strong hydration. The frequency-dependent shear viscosity showed bimodal relaxation, and the relative contribution of the slower mode increased with an increase in the salt concentration. The cross-correlation between the shear stress and the two-body density revealed that the slower viscoelastic mode is assigned to the dynamics of the heterogeneous structure, and the assignment was also confirmed by the comparison between the viscoelastic and structural relaxations. The collective translational motions of the cation and the anion showed a strong negative correlation in a concentrated solution, reflecting the heterogeneous domain structure.

IDENTIFICATION OF COARSE AGGREGATES PRONE TO SURFACE DETERIORATION AND D-CRACKING IN CONCRETE PAVEMENTS

This study investigates the influence of coarse aggregates on the durability of concrete pavements exposed to freezing and thawing cycles, particularly focusing on the phenomena of surface deterioration and D-cracking. Argillaceous aggregates from Indiana pavements showed significant surface damage within one to two years of construction, despite being from approved sources and the concrete being air entrained for freeze-thaw protection. The deterioration was linked to the aggregates themselves, with no apparent damage to the surrounding cement paste. The research aimed to understand the role of osmotic effects in the aggregates' failure by conducting laboratory experiments to simulate the freezing conditions with and without salt solutions. The findings revealed that the argillaceous aggregates exhibited osmotic phenomena, leading to an additional detrimental mechanism during freezing and thawing when a salt concentration gradient exists. This study confirms the significant impact of osmotic pressure on aggregate failure and suggests a simple testing procedure to identify aggregates prone to such deterioration. The results have implications for the selection and testing of coarse aggregates used in concrete pavements, particularly in environments where deicing agents are applied. (Abstract generated by AI tool ChatGPT 4)

Investigation of Chloride Salt Erosion on Asphalt Binders and Mixtures: Performance Evaluation and Correlation Analysis.

Asphalt pavement, widely utilized in transportation infrastructure due to its favourable properties, faces significant degradation from chloride salt erosion in coastal areas and winter deicing regions. In this study, two commonly used asphalt binders, 70# base asphalt and SBS (Styrene-Butadiene-Styrene)-modified asphalt, were utilized to study the chloride salt erosion effect on asphalt pavement by immersing materials in laboratory-prepared chloride salt solutions. The conventional properties and adhesion of asphalt were assessed using penetration, softening point, ductility, and pull-off tests, while Fourier transform infrared spectroscopy (FTIR) elucidated the erosion mechanism. The Marshall stability test, freeze-thaw splitting test, and Cantabro test were applied to study the effects of chloride exposure on the strength, water stability, and structural integrity of the asphalt mixture. Finally, the grey correlation analysis was employed to assess the impact of chloride salt erosion on the performance of asphalt binders and mixtures. The findings highlight that chloride salt erosion reduces penetration and ductility in both types of asphalt binders, raises the softening point, and weakens asphalt-aggregate adhesion, confirmed as a primarily physical effect by FTIR analysis. Asphalt mixtures showed decreased strength and water stability, intensifying these impacts at higher chloride concentrations and longer erosion duration. SBS-modified asphalt binders and mixtures exhibited greater resistance to chloride salt erosion, particularly in adhesion, as demonstrated by the Cantabro and pull-out tests. Grey relational analysis revealed that erosion duration is the most influential factor, with TSR and softening point emerging as the most responsive indicators of chloride-induced changes. These findings offer critical insights for practice, providing evidence-based guidance for designing and constructing asphalt pavements in environments with high chloride levels.

Quantification of vehicular versus uncorrelated Li+-solvent transport in highly concentrated electrolytes via solvent-related Onsager coefficients.

Highly concentrated salt solutions are promising electrolytes for battery applications due to their low flammability, their high thermal stability, and their good compatibility with electrode materials. Understanding transport processes in highly concentrated electrolytes is a challenging task, since strong ion-ion and ion-solvent interactions lead to highly correlated movements on the microscopic scale. Here, we use an experimental overdetermination method to obtain accurate Onsager transport coefficients for concentrated binary electrolytes composed of either sulfolane (SL) or dimethyl carbonate (DMC) as solvent and either LiTFSI or LiFSI as salt. NMR-based electrophoretic mobilities demonstrate that volume conservation applies as a governing constraint for the transport. This fact allows to calculate the Onsager coefficients σ+0, σ-0 and σ00 related to the solvent. A parameter γ is then defined, which is a measure for the relevance of a vehicular Li+-solvent transport mechanism. We analyze the influence of the salt anion and of the solvent on dynamic correlations and transport mechanisms. In the case of the sulfolane-based electrolytes, the γ parameter reaches values up to 0.38, indicating that Li+-sulfolane interactions are stronger than Li+-anion interactions and that vehicular Li+-sulfolane transport plays a significant role. In the case of DMC-based electrolytes, the γ parameter is close to zero, suggesting balanced Li+-DMC vs. Li+-anion interactions and virtually uncorrelated movements of Li+ ions and DMC molecules.

Changes in charge characteristics of nanoparticles modified by roughness brush layer

Nanoparticles modified with polyelectrolyte brushes have gained prominence as versatile tools in medical and biological contexts owing to their capacity to fulfill diverse functional roles. Therefore, it is crucial to conduct further research to understand the underlying mechanisms of polyelectrolyte brush-modified nanoparticles, in order to fully utilize their potential in medical and biological applications. When investigating the polyelectrolyte brush layer in the past, it was commonly thought to be a smooth circular structure. We created a mathematical model of brush-modified nanoparticles with various levels of roughness, which is inspired by the irregular protein structure of the virus surface. The charge characteristics of nanoparticles modified with roughness brush layers are investigated by manipulating parameters such as the pH value, salt solution content, and nanoparticle size. Our results demonstrate that the charge density of the surface of the brush layer will change periodically with the surface roughness pattern. Our findings reveal that the charge density at the top of the brush layer is highest, while the charge density at the bottom of the layer is the lowest. The influence of solution parameters on charge density is diminished under conditions in which the pH aligns with the isoelectric point of the layer and the solution concentration is high. During this period, the charge density is predominantly influenced by the roughness radius, leading to substantial variations in the charge density among brush layers with distinct roughness characteristics. As the particle radius increases, there is a concomitant decrease in charge density. These research findings establish a theoretical foundation for the practical utilization of nanoparticles.

Effect of glucose concentration on the corrosion behaviour of WE43 alloy in Hank’s balanced salt solution

Effect of glucose concentration on the corrosion behaviour of WE43 alloy in Hank’s balanced salt solution

Density gradients in aqueous salt solutions: A challenging calculation for electrolyte equations of state

Density gradients in aqueous salt solutions: A challenging calculation for electrolyte equations of state

Significantly improves the mechanical strength of aluminum alloy adhesive joint through electrochemical pretreatment in environmentally friendly medium

Adhesive bonding of aluminum alloys is extensively practiced to achieve optimum lightweight and reliable structures in the aerospace, automobile, and maritime industries. This paper represents the inaugural attempt to use neutral salt solutions as electrolytes for the electrochemical pretreatment of aluminum alloy bonding surfaces, with the aim of achieving high-performance bonding. The NaNO3 and NaCl solutions were selected carefully due to their non-toxic, easy to obtain, and inexpensive. Comprehensive experiments were conducted, and the specimen surfaces were characterized by advanced characterization methods before and after electrochemical treatment. The results demonstrated that the surface morphology of the treated aluminum alloy exhibited notable alterations, and the wettability, roughness, and chemical composition were effectively improved. Subsequently, aluminum alloy single lap joints were subjected to detailed examination in order to evaluate the effectiveness of the pretreatments on the bonding strength and fracture resistance. The results showed that under the condition of 5 A and 1 min, the specimen treated with NaCl solution demonstrated a notable enhancement in bonding performance, and its bonding strength increased by more than 200 % that of the untreated specimen joints. Moreover, this study integrates the characterization and experimental findings to provide a comprehensive analysis of the mechanisms underlying the deterioration or improvement of the bonding performances under different pretreatment conditions. This study demonstrates not only the extremely friendly characteristics to operators and environment, but also the technical advantages of low cost, high efficiency and good bonding performance.

Constructing a dual-layer PTFE nanofiltration membrane for enhanced salt solution permeability

Constructing a dual-layer PTFE nanofiltration membrane for enhanced salt solution permeability

Surface Doping to Suppress Iodine Ion Migration for Stable FAPbI3 Perovskite Quantum Dot Solar Cells

AbstractFormamidine lead iodide (FAPbI3) quantum dots (QDs) have attracted great attention as a new generation of photovoltaic material due to their long carrier diffusion length, benign ambient stability, and light‐harvesting ability. However, its large surface area with inherent thermodynamic instability and highly defective ionic termination are still major obstacles to fabricating high‐performance devices. Herein, a metallic ion dopant is developed to post‐treat FAPbI3 QDs immediately after their fabrication by using a metal‐glutamate salt solution. Both experimental and theoretical results show that alkaline (earth) metal ions (Mg2+, Na+, and K+) in their glutamate salt can not only successfully substitute insulating long‐chain ligands to form thinner ligand shells but inhibit the formation of iodine vacancies on the surface of QDs. As a result, the glutamate‐Mg based solar cell exhibits a champion efficiency of 13.48%, and the other two solar cells treated by glutamate alkaline metal salts (Na+ and K+) achieve photoelectrical conversion efficiencies of 13.26% and 11.88%, respectively, all of which are higher than of control cell with an efficiency of 11.58%. Therefore, this substantial progress provides intuitive cognition and guidance for the improvement of photoelectric performance and the commercial application of quantum dot solar cells.

БАКТЕРИАЛЬНОЕ ИЗВЛЕЧЕНИЕ ИОНОВ ТЯЖЕЛЫХ МЕТАЛЛОВ ИЗ ВОДНЫХ РАСТВОРОВ ИХ СОЛЕВЫХ СМЕСЕЙ

Bacteria isolated from industrial ecotopes of Ufa were studied for the uptake of metal ions from aqueous solutions of salts simulating the composition of wastewater. The study found that Pb(II) and Cr(VI) ions were the most accessible to the studied strains ‒ they were removed from solutions by three strains each: Bacillus megaterium 32T, Raoultella planticola 36D, Raoultella planticola 33-4CPA and Pseudomonas sp. 34DCP, B. megaterium 32T, R. planticola 36D, respectively. The ability to remove Fe(III) ions was revealed in two cultures ‒ Bacillus subtilis 19S and B. megaterium 32T, Cd(II) and Cu(II) ions were removed only by the Pseudomonas sp. 34DCP strain. The most difficult for heavy metals ions removing by bacteria were Co(II) ions; not a single strain could interact with them. With the highest efficiency, over 70%, Pb(II) ions were removed from aqueous solutions of salts by cells of the strains B. megaterium 32T and R. planticola 33 4CPA, as well as Cr(VI) ions by B. megaterium 32T and R. planticola 36D cultures. With an efficiency of over 50%, Cd(II) and Cu(II) ions were removed by the Pseudomonas sp. 34DCP culture, Pb(II) ions by the R. planticola 36D culture, and Fe(III) ions by the B. subtilis 19S culture, respectively. In other cases, the efficiency of heavy metals ions removing from aqueous solutions of salts by bacteria was lower (from 37% to 41%).

ИССЛЕДОВАНИЕ НАБОРА ПРОЧНОСТИ ТЯЖЕЛОГО БЕТОНА В АГРЕССИВНОЙ СРЕДЕ. С ИСПОЛЬЗОВАНИЕМ СУЛЬФАТОСТОЙКОГО ЦЕМЕНТА

Experimental data are presented on changes in the compressive strength of heavy concrete using sulfate-resistant cement, Crimean aggregates and additives based on polycarboxylate ethers when kept in an aggressive environment - liquid from water treatment facilities in an urban-type settlement Gvardeiskoe, Simferopol district, Republic of Crimea. Compositions of heavy concrete have been developed using hyperplasticizing (polycarboxylate) additives that are capable of increasing their physical and mechanical characteristics over time when operating in aggressive environments. It is relevant to further develop the theoretical and experimental foundations for the production of cement concrete using the latest generation of superplasticizing additives based on polycarboxylates for wastewater treatment and recreational facilities. The durability of cement concrete is a key issue when using it in wastewater treatment and recreational facilities. Cement concrete can be susceptible to sulfate corrosion. Sulfates have a complex mechanism of action on the chemically active component of concrete - cement stone. Sulfates have a complex mechanism of action on the chemically active component of concrete - cement stone. The corrosive effect can increase or decrease depending on the concentration of aggressive components, with varying levels of exposure to salt solutions on the concrete structure, periodic drying, and partial immersion. This is due to the fact that the chemical processes of interaction between an aggressive environment and cement stone in concrete are influenced by physical processes of mass transfer of soluble components and crystallization of corrosion products or soluble components, which can accelerate or inhibit chemical processes. The parameters of the strength characteristics of the optimized compositions at different periods of strength gain have been established, and the average density and water resistance of the optimized concrete compositions have been established.