Slight Excess Research Articles

A Titration Method for Standardization of Aqueous Sodium Chlorite Solutions Using Thiourea Dioxide.

Accurate and cost-effective methods for the analysis of oxychlorine compounds in water are critical to modern chlorine-based water treatment. With alternatives to elemental chlorine and hypochlorite bleaches growing in popularity, simple quantification methods for the disinfectant chlorine dioxide (ClO2) in water, as well as chlorite (ClO2-) and chlorate (ClO3-), which are commonly used precursors in ClO2 generation, are required. However, currently, regulated standard methods require specialized equipment and do not effectively discriminate between molecular and ionic species. In this contribution, we present a simple titration-based method for chlorite determination in water using commercially available and easy-to-handle reagents. Specifically, chlorite is reduced with a slight excess of thioureadioxide (TUD). The remaining reductant is then back-titrated against a known amount of potassium permanganate, affording calculatable chlorite concentrations through measured consumption of a reductant and a clear visual endpoint upon accumulation of excess KMnO4. Straightforward methods for chlorite standardization with reasonable error and accuracy for field and/or lab application have the potential to greatly enhance quality assurance and therefore assist in resource deployment in water treatment.

Ultralow-loss Sr1+xMgGe2O6+x ceramics: Sintering behavior, microstructure, covalence, lattice vibration, and dielectric properties

Sr1+xMgGe2O6+x ceramics were prepared by the solid-state reaction method (SSR). The effects of Sr2+ non-stoichiometry on phase composition, sintering characteristics, microstructure, and microwave properties were analyzed. XRD detected a slight excess of strontium to produce the secondary phase Sr2MgGe2O7. Rietveld refinement obtained the structural parameters, and the crystal structure was studied. SEM revealed that excessive strontium promoted grains' growth and increased ceramics' density. Raman spectrum indicates that the FWHM is closely related to microwave properties. The change of Q × f was explained by analyzing the packing fraction and average covalence. The distortion of the GeO4 tetrahedron and bond energy revealed the relationship between τf and crystal structure. Sr1.03MgGe2O6.03 ceramics sintered at 1250 °C have the best microwave properties of εr = 8.69, Q × f = 77660 GHz, τf = −74 ppm/°C.

An efficient site-selective, dual bioconjugation approach exploiting N-terminal cysteines as minimalistic handles to engineer tailored anti-HER2 affibody conjugates

Site-selective, dual-conjugation approaches for the incorporation of distinct payloads are key for the development of molecularly targeted biomolecules, such as antibody conjugates, endowed with better properties. Combinations of cytotoxic drugs, imaging probes, or pharmacokinetics modulators enabled for improved outcomes in both molecular imaging, and therapeutic settings. We have developed an efficacious dual-bioconjugation strategy to target the N-terminal cysteine of a chemically-synthesized, third-generation anti-HER2 affibody. Such two-step, one-purification approach can be carried out under mild conditions (without chaotropic agents, neutral pH) by means of a slight excess of commercially available N-hydroxysuccinimidyl esters and maleimido-functionalized payloads, to generate dual conjugates displaying drugs (DM1/MMAE) or probes (sulfo-Cy5/biotin) in high yields and purity. Remarkably, the double drug conjugate exhibited an exacerbated cytoxicity against HER2-expressing cell lines as compared to a combination of two monoconjugates, demonstrating a potent synergistic effect. Consistently, affibody-drug conjugates did not decrease the viability of HER2-negative cells, confirming their specificity for the target.

Correlation between Interfacial Structures and Device Performance: The Double-Edged Sword Effect of Lead Iodide in Perovskite Solar Cells.

The interfacial electronic structure of perovskite layers and transport layers is critical for the performance and stability of perovskite solar cells (PSCs). The device performance of PSCs can generally be improved by adding a slight excess of lead iodide (PbI2 ) to the precursor solution. However, its underlying working mechanism is controversial. Here, we performed a comprehensive study of the electronic structures at the interface between CH3 NH3 PbI3 and C60 with and without the modification of PbI2 using in situ photoemission spectroscopy measurements. The correlation between the interfacial structures and the device performance was explored based on performance and stability tests. We found that there is an interfacial dipole reversal, and the downward band bending is larger at the CH3 NH3 PbI3 /C60 interface with the modification of PbI2 as compared to that without PbI2 . Therefore, PSCs with PbI2 modification exhibit faster charge carrier transport and slower carrier recombination. Nevertheless, the modification of PbI2 undermines the device stability due to aggravated iodide migration. Our findings provide a fundamental understanding of the CH3 NH3 PbI3 /C60 interfacial structure from the perspective of the atomic layer and insight into the double-edged sword effect of PbI2 as an additive.

Organocatalyzed Mannich reaction: Electrochemically synthesized prolinated carbon dots vs. prolinated graphene oxide

Background L-Pro was previously used as an organocatalyst in the Mannich reaction under homogeneous conditions; a recoverable catalyst could be useful; this is the first report on the application of prolinated carbon dots to the Mannich reaction. Methods Prolinated carbon dots were synthesized electrochemically using a bottom-up approach; they were characterized and used in the Mannich reaction in water using only a slight excess of ketone; for a useful comparison, L-proline decorated graphene oxide was synthesized. Results The characterization of carbon dots and functionalized graphene oxide confirmed the presence of L-Pro on their surface; their use in the Mannich reaction gave good yields when carrying out the reaction in water; a possible recycle of the catalyst was demonstrated. Conclusions Both electrochemically synthesized prolinated carbon dots and prolinated graphene oxide acted as organocatalysts in the Mannich reaction. Higher yields were obtained using L-Pro-CDs obtained under galvanostatic conditions.

Growth Process, Structure and Electronic Properties of Cr2GeC and Cr2-xMnxGeC Thin Films Prepared by Magnetron Sputtering

The growth and phase formation features, along with the influence of structure and morphology on the electronic, optical, and transport properties of Cr2GeC and Cr2-xMnxGeC MAX phase thin films synthesized by magnetron sputtering technique, were studied. It was found that the Cr:Ge:C atomic ratios most likely play the main role in the formation of a thin film of the MAX phase. A slight excess of carbon and manganese doping significantly improved the phase composition of the films. Cr2GeC films with a thicknesses exceeding 40 nm consisted of crystallites with well-developed facets, exhibiting metallic optical and transport properties. The hopping conduction observed in the Cr2-xMnxGeC film could be attributed to the columnar form of crystallites. Calculations based on a two-band model indicated high carrier concentrations N, P and mobility μ in the best-synthesized Cr2GeC film, suggesting transport properties close to single crystal material. The findings of this study can be utilized to enhance the growth technology of MAX phase thin films.

Factors affecting productive longevity of cows of Red-and-White breed

The duration of economic use of cows is one of the important economic indicators in dairy cattle breeding, which determines the total amount of dairy products received from the cow and the speed of herd repair. A short period of use of cows causes economic damage to dairy cattle breeding and leads to the loss of valuable genotypes. Productive longevity of cows is the potential to increase the efficiency of dairy cattle breeding; therefore it can be a priority direction of breeding. There are quite a lot of reasons for the culling of animals from the herd, and they have their own specifi cs in each farm. The purpose of the research was to study the factors aff ecting the productive longevity of cows of Red-and-White breed in pedigree farms. The research was carried out under the conditions of breeding ferms in the Voronezh region, which Red-and-White breed of cattle bred such as JSC “Troitskoye” and JSC “Mayak” of Liskinsky district, LLC “Agrotech-Garant” Nashchekino of Anninsky district. It was found that the average milk yield of cows in all farms was 7497±532 kg (the best result was obtained in LLC “Mayak” – 8034 kg), which signifi cantly exceeds the requirements of the breed standard. The average percentage of fat in milk was 3,79 ± 0,11 %, protein – 3,22± 0,07 %, which meets the requirements of the breed standard. Analysis of the duration of productive use of cows in the herd showed that the average age at calving was 2,73 ± 0,26. A slight excess was observed in JSC “Troitskoe” (by 0,47 calving or 17,1 %). It was revealed as a result of the research that the best productive longevity and the highest productivity over the period of life in farms were found in cows calved at the age of 26–28 months, with a live weight of 480 – 520 kg, with milk yield for the fi rst lactation to 5000–6000 kg of milk, having an open days period of 60–90 days. It was found, farms have significant reserves to increase the productive longevity of cows by improving breeding work and veterinary activates.

Atomistic Understanding of the Coherent Interface Between Lead Iodide Perovskite and Lead Iodide

AbstractMetal halide perovskite semiconductors have shown great performance in solar cells, and including an excess of lead iodide (PbI2) in the thin films, either as mesoscopic particles or embedded domains, often leads to improved solar cell performance. Atomic resolution scanning transmission electron microscope micrographs of formamidinium lead iodide (FAPbI3) perovskite films reveal the FAPbI3:PbI2 interface to be remarkably coherent. It is demonstrated that such interface coherence is achieved by the PbI2 deviating from its common 2H hexagonal phase to form a trigonal 3R polytype through minor shifts in the stacking of the weakly van‐der‐Waals‐bonded layers containing the near‐octahedral units. The exact crystallographic interfacial relationship and lattice misfit are revealed. It is further shown that this 3R polytype of PbI2 has similar X‐ray diffraction (XRD) peaks to that of the perovskite, making XRD‐based quantification of the presence of PbI2 unreliable. Density functional theory demonstrates that this interface does not introduce additional electronic states in the bandgap, making it electronically benign. These findings explain why a slight PbI2 excess during perovskite film growth can help template perovskite crystal growth and passivate interfacial defects, improving solar cell performance.

Genetic structure of the herds of two bighead carp species in «Аgrofirm Кolos» PLC

The allelic and genotypic composition of herds of silver carp and bighead carp of Agrofirma Kolos PLC (Kyiv region) was studied. The method of electrophoresis in a polyacrylamide gel with histochemical staining and subsequent genotyping of samples according to the three most variable blood proteins: transferrin, albumin, and esterase is used to detect molecular genetic markers. The number of three-year-old fish that were used to take blood samples for genetic research was 20 specimens for each species of fishes. The frequency of alleles and genotypes, actual and expected heterozygosity, and fixation indices were calculated. According to the results of the study, the predominance of heterozygous genotypes over homozygous genotypes at all three studied loci was found in the herds of both types of fish. The highest level of heterozygosity was established at the transferrin locus (98% in silver carp and 66.2% in bighead carp), the lowest was at the albumin locus (65% in silver carp and 50.8% in bighead carp). A slight excess of heterozygous individuals was found for transferrin and esterase loci in the herd of silver carp. For the bighead carp, this was found only in the transferrin locus. The influence of inbreeding on the formation of the genetic structure of herds of both species of fishes was revealed. To prevent the negative impact of inbreeding, it is recommended to use the high genetic variability of herds for the heterogeneous selection of fish for breeding purposes and to carry out cyclic genetic monitoring of the stock.

Photoinduced Minisci Reaction with Diazines: An Approach Toward Original Fused Heterocycles.

Herein, we developed a photoinduced Minisci reaction on a large panel of diazines with good to excellent yields (28 examples, 44% to 89%). The reaction using 4CzIPN (1 mol%) as photoinitiator was carried out under white LED irradiation and required a slight excess of the acid reagent (1.2 equiv.). Cyclization reactions were then developed to access original N-heterocycles building blocks for drug discovery programs. An extension of the reaction to continuous flow was also reported. Finally, the mechanism of the transformation was studied suggesting a plausible radical chain mechanism.

Search for flavour-changing neutral current interactions of the top quark and the Higgs boson in events with a pair of τ-leptons in pp collisions at sqrt{s} = 13 TeV with the ATLAS detector

A search for flavour-changing neutral current (FCNC) tqH interactions involving a top quark, another up-type quark (q = u, c), and a Standard Model (SM) Higgs boson decaying into a τ-lepton pair (H → τ+τ−) is presented. The search is based on a dataset of pp collisions at sqrt{s} = 13 TeV that corresponds to an integrated luminosity of 139 fb−1 recorded with the ATLAS detector at the Large Hadron Collider. Two processes are considered: single top quark FCNC production in association with a Higgs boson (pp → tH), and top quark pair production in which one of top quarks decays into Wb and the other decays into qH through the FCNC interactions. The search selects events with two hadronically decaying τ-lepton candidates (τhad) or at least one τhad with an additional lepton (e, μ), as well as multiple jets. Event kinematics is used to separate signal from the background through a multivariate discriminant. A slight excess of data is observed with a significance of 2.3σ above the expected SM background, and 95% CL upper limits on the t → qH branching ratios are derived. The observed (expected) 95% CL upper limits set on the t → cH and t → uH branching ratios are 9.4times {10}^{-4}left({4.8}_{-1.4}^{+2.2}times {10}^{-4}right) and 6.9times {10}^{-4}left({3.5}_{-1.0}^{+1.5}times {10}^{-4}right) , respectively. The corresponding combined observed (expected) upper limits on the dimension-6 operator Wilson coefficients in the effective tqH couplings are Ccϕ< 1.35 (0.97) and Cuϕ< 1.16 (0.82).

Carbon-neutral synfuel production via continuous solar H2O and CO2 gasification of oil palm empty fruit bunch

Solar gasification offers a promising carbon-neutral pathway to thermochemically convert waste biomass and solar energy into synfuel. In this study, a thermodynamic analysis of solar gasification of oil palm empty fruit bunch (EFB) with H2O and CO2 gasifying agents was first performed to predict equilibrium product distribution. Subsequently, on-sun continuous solar gasification of EFB was experimentally carried out in a solar particle-fed gasifier to evaluate the influence of gasifying agent types (H2O and CO2), gasifying agent/EFB molar ratios (1.8–3.4), temperatures (1050–1350 °C), and to assess overall process feasibility and reliability. As a result, solar EFB gasification performed efficiently with both H2O and CO2 gasifying agents under continuous on-sun operation. Syngas product composition and gasification reaction rate strongly depended on gasifying agent type. Increasing temperature enhanced syngas yield and quality, and changed the CO/H2 mole ratio, especially in EFB + CO2 gasification. A gasifying agent/EFB molar ratio of 2.6 (slight excess of gasifying agents) and a temperature of 1300 °C were shown to be optimal for continuous solar EFB gasification. The maximum total syngas yield above 76 mmol/gdry_EFB, syngas lower heating value above 22 kJ/gdry_EFB, and energy upgrade factor above 1.37 were achieved from both EFB + H2O and EFB + CO2 gasification, which closely approached their theoretical equilibrium values. The maximum carbon conversion exceeding 93% and solar-to-fuel energy conversion efficiency up to 19.3% were achieved, demonstrating efficient EFB-to-synfuel conversion performance. Continuous solar EFB gasification with both H2O and CO2 was thus established to be a reliable process for EFB waste biomass valorization into high-quality and carbon-neutral synfuel.

The problem of quality and safety of alcohol products

This article considers the main problems of quality and safety of alcohol products, as well as possible ways to solve this problem. Alcohol is one of the most common psychoactive substances in the world. The quality and safety of alcohol products and ethyl alcohol are often threatened and cause serious concerns from consumers, government agencies, and the general public. Many alcohol producers are interested in creating products with the maximum amount of alcohol and the minimum cost. This leads to the use of low-grade ingredients, the mixing of different types of alcohol, and a significant increase in alcohol content to critical levels. This can cause even more serious consequences for people's health, especially for those who already have problems with alcohol addiction. One of the urgent problems of Russian consumer market is adulteration of alcohol products sold to population through retail trade network. Consumption of adulterated alcoholic beverages is dangerous to life due to high content of toxic impurities. Even a slight excess of impurities can cause intoxication of the human body, having toxic, allergenic, immunomodulatory, genotoxic effect that negatively affects the reproduction function, hormonal regulation. In order to solve the problem of quality and safety of alcohol products, it is necessary to carry out its qualitative control at each stage of production. This will help to exclude the use of low-quality raw materials, improper combination of components and violation of technological processes. To combat unlicensed production, it is necessary to toughen penalties for its implementation. It is also necessary to monitor the market and identify cases of sale of illegal products.

Adaptation of Zemplén's conditions for a simple and highly selective approach to methyl 1,2−trans glycosides

1,2-trans methyl glycosides can be readily obtained from peracetylated sugars through their initial conversion into glycosyl iodide donors and subsequent exposure of these latter to a slight excess of sodium methoxide in methanol. Under these conditions a varied set of mono- and disaccharide precursors afforded the corresponding 1,2-trans glycosides with concomitant de-O-acetylation in satisfying yields (in the range 59–81%). A similar approach also proved effective when using GlcNAc glycosyl chloride as the donor.

A highly efficient and specific “grafting to” route for stable protein-polymer conjugates based on Spy chemistry

The coupling of protein and polymer utilizing grafting to method has always suffered from poor efficiency and specificity. In this work, we developed a highly efficient and specific approach for the grafting to synthesis of stable protein-polymer conjugates based on Spy chemistry. The conjugation of Spytag-terminated polymers (∼24 kDa) and genetically engineered model protein SpyCatcher-sf GFP (∼40 kDa) was completed with a slight excess of polymers (1.5 eq.) in aqueous solution within 30 min at room temperature. Furthermore, the conjugation reaction was independent of interferents and the covalent binding was shown to be resistant to boiling and remained intact for at least 3 months at 4 °C, exhibiting favorable specificity and stability. Specifically, oxidative tolerance of protein (A1AT) was highly enhanced after conjugation with Se containing polymers. This novel protein-polymer conjugation strategy is expected to develop abundant hybrid platforms for fields like diseases treatment, and provides a new view for the exploration of conjugation methods.

Reciprocal irreversibility compensation of LiNi0.2Co0.2Al0.1Mn0.45O2 cathode and silicon oxide anode in new Li-ion battery

A layered LiNi0.2Co0.2Al0.1Mn0.45O2 cathode is herein synthetized and investigated. Scanning electron microscopy (SEM) shows the layered morphology of the composite powder, while energy dispersive X-ray spectroscopy (EDS) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) confirm the achieved stoichiometry. X-ray diffraction (XRD) well identifies the layered structure unit cell, and Raman spectroscopy displays the corresponding M-O bonds motions. The cycling voltammetry (CV) of LiNi0.2Co0.2Al0.1Mn0.45O2 in lithium half-cell reveals an electrochemical process characterized by a remarkable irreversible oxidation taking place at 4.6 V vs. Li+/Li during the first scan, and subsequent reversible Li (de)intercalation centered at 3.8 V vs. Li+/Li with interphase resistance limited to 16 Ω upon activation as indicated by electrochemical impedance spectroscopy (EIS). The relevant irreversibility during first charge is also detected by galvanostatic cycling in a lithium half-cell subsequently operating at an average voltage of 3.8 V with a stable trend, and a maximum specific capacity of 130 mAh g−1. The initial irreversible capacity of the layered cathode is advantageously exploited for compensating the pristine inefficiency of the Li-alloying composite anode in a proof-of-concept Li-ion battery achieved by combining the LiNi0.2Co0.2Al0.1Mn0.45O2 with a silicon oxide composite (SiOx-C) without any preliminary pre-treatment of the electrodes. The full-cell displays a cycling behavior strongly influenced by the anode/cathode ratio, and the corresponding EIS performed both on the single electrodes and on the Li-ion cell by using an additional lithium reference suggests a controlling role of the anode interphase and possible enhancements through a slight excess of cathode material.

Surface Defects Management by In Situ Etching with Methanol for Efficient Inverted Inorganic Perovskite Solar Cells

AbstractInorganic perovskite solar cells (IPSCs) have developed rapidly due to their good thermal stability and the bandgap suitable for perovskite/silicon tandem solar cells. However, the large open‐circuit voltage (VOC) deficit derived from the surface defects and the energy level structure mismatch impede the development of device performance, especially in the P‐I‐N structure IPSCs. Herein, an innovative in situ etching (ISE) treatment method is proposed to reduce surface defects through methanol without additional passivator. It is found that the perovskite films treated with methanol result in a slight excess of PbI2 on the surface and inserted into the grain boundaries. Therefore, the successful decrease of surface defects by methanol and the passivation of grain boundary defects by PbI2 greatly reduce the trap density of perovskite films. And the larger work function of PbI2 contributes to the energy band of perovskite surface bending downward and forms gradient energy level alignment at the I/N interface, which accelerates extraction of charge carriers. As a result, the efficiency of CsPbI2.85Br0.15 inverted IPSC is enhanced from 16.00% to 19.34%, which is one of the mostly efficient IPSCs. This work provides an original idea without additional passivator to manage the defects of inorganic perovskite.

Synthesis of Ni-B Compounds by High-Pressure and High-Temperature Method.

Nickel borides are promising multifunctional materials for high hardness and excellent properties in catalysis and magnetism. However, it is still a blank of intrinsic properties in Ni-B compounds, because crystallization of the single phases of Ni-B compounds with micro-size is a challenge. In this work, single phases of Ni2B (I4/mcm), α-Ni4B3 (Pnma), β-Ni4B3 (C2/c), and NiB (Cmcm) are synthesized by high pressure and high temperature (HPHT). The results indicate that synthesizing α-Ni4B3 and β-Ni4B3 requires more energy than Ni2B and NiB. The growth process of Ni-B compounds is that Ni covers B to form Ni-B compounds under HPHT, which also makes the slight excess of B necessary. So, generating homogeneous distribution of starting materials and increasing the interdiffusion between Ni and B are two keys to synthesize well crystallized and purer samples by HPHT. This work uncovers the growth process of Ni-B compounds, which is significant to guide the synthesis of highly crystalline transition metal borides (TMBs) in the future.

Raised in changing climatic conditions arid conditions of the Volga region

The author proved the high adaptive abilities of sheep of the Stavropol breed, indicators of meat productivity and meat quality, as well as the possibility of further breeding of this breed in arid conditions. The research was conducted in CJSC "New Life" of the Novouzensky district of the Saratov region. The object of research was purebred rams of the Stavropol breed of different intrabreed productivity types. It was found that sheep of wool and wool-meat types grew equally from birth to weaning from mothers, but at 7.5 months the wool-meat type had a live weight of 4.83% higher compared to wool. Morphobiochemical parameters in young animals of both groups were within acceptable norms, but a slight excess was found in the wool-meat type. Sheep of the wool-meat type were superior to wool in pre–slaughter live weight by 4.83%, the mass of the paired carcass – 9.22%, in slaughter yield - 1.73%. The young animals of the wool-meat type had more protein by 0.60%, the wool-fat by 0.70%, so their meat is more complete.

Problems of the safe use of modern cement materials in the practice of drinking water supply

Introduction. Recently, there have been increasing changes in the technology of preparation of cement mixtures and concrete, the use of new components in their composition, since traditional materials are not quite suitable for the construction of hydraulic structures, including the internal coating of pipes and drinking water tanks. However, in addition to improving the characteristics of cement mixtures, additives can have a negative impact on the environment and human health by leaching out of cement into drinking water. The definition of only the main components specified in the “Universal sanitary-epidemiological and hygienic requirements for goods subject to sanitary-epidemiological supervision (control)” (hereinafter - the Universal Requirements) does not provide complete information about the chemical safety of cement materials during the hygienic assessment. Materials and methods. There were studied eleven samples of cement mixtures from various manufacturers repaired of reinforced concrete products and structures of general and special purpose, including those in contact with drinking water, and used for the sanitation of the internal surfaces of steel pipelines (including hot water supply systems) and repair and restoration work. The evaluation of samples was carried out taking into account Universal requirements, and indicators that are not mandatory for the evaluation of these materials were investigated. Results. Hygienic assessment of cement mixtures showed lithium to be detected in some extracts in concentrations from 20 mg/L to 0.18 mg/L, which is 666 times higher than its maximum permissible concentration - 0.03 mg/L. Also, two samples showed a slight excess of the permissible chromium concentration - 0.065 mg/L and 0.09 mg/L (MPC &lt; 0.05). Iron and zinc in insignificant concentrations were found in aqueous extracts; in one of the samples a 2-fold excess of the manganese concentration was observed. One water extract contains silicates at a concentration of 34.24 mg/L, which exceeds their permissible levels in drinking water. The analysis also identified a number of organic compounds related to oxygen-containing compounds (alcohols, phenol derivatives, ketones, esters, phthalates), for most of which no MPC has been established. Limitations. The study was carried out on eleven samples of cement mixtures under standard conditions: infusion in model media for 30 days at room temperature in the ratio: 1 cm2 of the sample surface to 1 cm3 of water. Sampling was carried out on the Days 1, 3, 5, 10, 20 and 30 of research, without changing the test water. It is necessary to conduct similar studies under experimental conditions close to the operating conditions of these materials. Conclusion. Assessing the efficiency of migration from cement-bound materials, it is necessary to take into account their capillary-porous structure on the one hand and the ability to improve the coating properties over time by converting calcium hydroxide present in freshly applied cladding into denser calcium bicarbonate. The migration of chemicals from cement-bound material is to be evaluated by taking into account the specific conditions of their use in the practice of drinking water supply, and the assessment of the additives introduced should be carried out on test cement samples, since it is impossible to theoretically calculate the migration rate of the components from the finished material.