Blended Product Research Articles

An investigation of alkaline phosphatase enzymatic activity after electrospinning and electrospraying

The high target specificity and multifunctionality of proteins has led to great interest in their clinical use. To this end, the development of delivery systems capable of preserving their bioactivity and improving bioavailability is pivotal to achieve high effectiveness and satisfactory therapeutic outcomes. Electrohydrodynamic (EHD) techniques, namely electrospinning and electrospraying, have been widely explored for protein encapsulation and delivery. In this work, monoaxial and coaxial electrospinning and electrospraying were used to encapsulate alkaline phosphatase (ALP) into poly(ethylene oxide) fibres and particles, respectively, and the effects of the processing techniques on the integrity and bioactivity of the enzyme were assessed. A full morphological and physicochemical characterisation of the blend and core-shell products was performed. ALP was successfully encapsulated within monolithic and core-shell electrospun fibres and electrosprayed particles, with drug loadings and encapsulation efficiencies of up to 21% and 99%, respectively. Monoaxial and coaxial electrospinning were equally effective in preserving ALP function, leading to no activity loss compared to fresh aqueous solutions of the enzyme. While the same result was observed for monoaxial electrospraying, coaxial electrospraying of ALP caused a 40% reduction in its bioactivity, which was attributed to the high voltage (22.5 kV) used during processing. This demonstrates that choosing between blend and coaxial EHD processing for protein encapsulation is not always straightforward, being highly dependent on the chosen therapeutic agent and the effects of the processing conditions on its bioactivity.

Blending Noah, SMOS and In-Situ Soil Moisture Using Multiple Weighting and Sampling Schemes

AbstractSoil moisture can be obtained from in-situ measurements, satellite observations, and model simulations. This study evaluates the importance of in-situ observations in soil moisture blending, and compares different weighting and sampling methods for combining model, satellite, and in-situ soil moisture data to generate an accurate and spatially-continuous soil moisture product at 4-km resolution. Four different datasets are used: Antecedent Precipitation Index (API), KAPI, which incorporates in-situ soil moisture observations with the API using regression kriging, SMOS L3 soil moisture, and model-simulated soil moisture from the Noah model as part of the North American Land Data Assimilation System (NLDAS). Triple collocation, least square weighting, and equal weighting are used to generate blended soil moisture products. An enumerated weighting scheme is designed to investigate the impact of different weighting schemes. The sensitivity of the blended soil moisture products to sampling schemes, station density and data formats (absolute, anomalies and percentiles) are also investigated. The results reveal KAPI outperforms API. This indicates that incorporating in-situ soil moisture improves the accuracy of the blended soil moisture products. There are no statistically significant (p>0.05) differences between blended soil moisture using triple collocation and equal weighting approaches, and both methods provide sub-optimal weighting. Optimal weighting is achieved by assigning larger weights to KAPI and smaller weights to SMOS. Using multiple sources of soil moisture is helpful for reducing uncertainty and improving accuracy, especially when the sampling density is low, or the sampling stations are less representative. These results are consistent regardless of how soil moisture is represented (absolute, anomalies or percentiles).

An Experimental Study on the Performance Characteristics of a Diesel Engine Fueled with ULSD-Biodiesel Blends

As a rule, the highest permissible sulfur content in the marine fuel must drop below 0.5% from 1 January 2020 for global fleets. As such, ships operating in emission control areas must use low sulfur or non-sulfur fuel to limit sulfur emissions as a source of acid rain. However, that fact has revealed two challenges for the operating fleet: the very high cost of ultra-low sulfur diesel (ULSD) and the installation of the fuel conversion system and the ULSD cooling system. Therefore, a solution that blends ULSD and biodiesel (BO) into a homogeneous fuel with properties equivalent to that of mineral fuels is considered to be significantly effective. In the current work, an advanced ultrasonic energy blending technology has been applied to assist in the production of homogeneous ULSD-BO blends (ULSD, B10, B20, B30, and B50 with blends of coconut oil methyl ester with ULSD of 10%, 20%, 30% and 50% by volume) which is supplied to a small marine diesel engine on a dynamo test bench to evaluate the power and torque characteristics, also to consider the effect of BO fuel on specific fuel consumption exhaust gas temperature and brake thermal efficiency. The use of the ultrasonic mixing system has yielded impressive results for the homogeneous blend of ULSD and BO, which has contributed to improved combustion quality and thermal efficiency. The results have shown that the power, torque, and the exhaust gas temperature, decrease by approximately 9%, 2%, and 4% respectively with regarding the increase of the blended biodiesel rate while the specific fuel consumption and brake thermal efficiency tends to increase of around 6% and 11% with those blending ratios.

Empowering Women in the Agricultural Value Chain Via Islamic Blended Products to Attain the Agenda 2030 in The Gambia

The importance of gender equality and women empowerment has become the central piece in numerous development agenda around the globe. In the Gambia, as part of the national development agenda, the government has eye marked key priority areas to champion the course of women empowerment. In addition, the government has enacted laws and ratified several other international goals including the Agenda 2030 to support this course. However, women entrepreneurs especially those in the agriculture value chain have faced numerous financial management challenges in conducting business activities. On one hand bank loans are expensive for them, and other the other hand those with surplus got minimal returns on their savings and investments. Thus, this paper aims to deliver the intended outcome of Maqasid Al Shariah by harnessing Islamic social financing and utilizing funds from the surplus side to provide sustainable and impactful financing for women on the deficit side via Islamic Blended finance. In addition to de-risking investment towards women empowerment, our proposed model offers a better return for those on the supply side and cheaper rate for those on the demand side by minimizing intermediation and transaction cost. It is anticipated that this paper will contribute to the achievement of the 2030 Agenda in The Gambia and also has the potential to be replicated in other developing countries.

Northwest monsoon upwelling within the Indonesian seas

ABSTRACT The previous studies of upwelling within the Indonesian seas only focused on the Southeast Monsoon (SEM) season. The western coast of Sumatra Island; the southern coast of Java Island, Sunda Islands, and Sulawesi Island; the Banda Sea, the Maluku Sea, and the Arafura Sea are well-known SEM upwelling areas. However, the upwelling events during Northwest monsoon (NWM) have never been investigated. The investigation of NWM upwelling is challenging due to the broad cloud coverage, limiting the observation of infrared and visible sensors of the satellites. This study used the blended products of the satellite-based sea surface temperature (SST), chlorophyll-a (chl-a), sea level anomaly (SLA), surface wind, and rainfall to identify the NWM upwelling occurrences. Remote sensing reflectances 443 nm and 555 nm were also used to examine the influence of suspended sediment and organic matter which may bias the chl-a concentration. Along the northern coast of the Lesser Sunda Islands, the north coast of Papua Island and the Malacca Strait are the areas of NWM upwelling as denoted by the positive anomaly of chl-a, the negative anomaly of SST, and the negative anomaly of SLA. Focusing on the area along the northern coast of the Lesser Sunda Islands, the NWM upwelling is generated by offshore Ekman Mass Transport that reduces SST and increases chl-a. From 2010 onwards, El Niňo Southern Oscillation has a more consistent effect on the NWM upwelling than Indian Ocean Dipole. El Niňo (La Niňa) tends to weaken (strengthen) upwelling. The magnitude of NWM upwelling is weaker than SEM upwelling.

The response of citrus plants to the broad mitePolyphagotarsonemus latus(Banks) (Acari: Tarsonemidae)

Polyphagotarsonemus latus(Banks) (Acari: Tarsonemidae) is a common polyphagous mite in tropical and subtropical areas and is considered as an important citrus pest.To understand the response of citrus toP. latusinfestation, we have characterized the volatile profile and the molecular defence mechanisms of two citrus genotypes, namely sour orange (Citrus aurantium) and Cleopatra mandarin (Citrus reshni), toP. latusinfestation. These two species are important rootstocks for the citrus industry and display differential resistance toTetranychus urticaeKoch (Acari: Tetranychidae), with sour orange showing elevated levels of constitutive and induced resistance associated with the jasmonic acid (JA) pathway compared with Cleopatra mandarin.P. latusinfestation activated both the JA‐ and the salicylic acid‐dependent pathways in sour orange but not in Cleopatra mandarin. However, this differential activation resulted in the production of similar volatile blends (a mixture of green leaf volatiles and aromatic compounds).Contrary toT. urticaeinfestation, sour orange supported larger densities ofP. latusthan Cleopatra mandarin with similar injury levels.Therefore, sour orange may be more tolerant toP. latusthan Cleopatra mandarin.

A generalizable strategy toward highly tough and heat-resistant stereocomplex-type polylactide/elastomer blends with substantially enhanced melt processability

Sustainable stereocomplex-type polylactide (SC-PLA) has been recognized as a potential substitute for some traditional engineering plastics, however its widespread application still faces several hurdles primarily related to poor melt processability (i.e., the unfavorable melt memory effect in SC crystallization as well as the low melt strength) and insufficient fracture toughness. To overcome these hurdles, an equimolar poly(l-lactide)/poly(d-lactide) (PLLA/PDLA) blend toughened with poly(ethylene-co-vinyl acetate) (EVA) has been chosen as a model system and a facile strategy has been devised by incorporating trace amounts (i.e., 0.5 wt%) of epoxy-functionalized oligo(styrene-acrylic) (ESA) into the PLLA/PDLA/elastomer blends through direct melt-blending at 200 °C. Such a one-pot blending not only facilitates the stereocomplexation between PLLA and PDLA chains but also permits the highly efficient reaction between terminal hydroxyl groups of some enantiomeric PLAs and epoxy groups of ESA before their stereocomplexation. This results in the in situ generation of large amounts of long-chain-branched PLA-graft-ESA copolymer in the SC-PLA matrix. Very impressively, the generation of this PLA-graft-ESA copolymer gives rise to a substantial improvement in the melt memory effect of the SC-PLA matrix. This copolymer behaves as a compatibilizer to stabilize regular PLLA/PDLA chain clusters in blend melts and hence to stimulate the exclusive formation of SC crystallites in melt-processed blend products. In addition, long PLA branches endow the matrix with a considerably enhanced melt viscosity owing to the increased interchain entanglement density. Consequently, highly stereocomplexed SC-PLA/EVA products with exceptional impact toughness and heat resistance as well as robust mechanical strength have been prepared by injection molding. More notably, this strategy can be generalized to various SC-PLA-based blends, irrespective of whether the elastomers have reactive groups. Overall, these exciting findings illustrate a promising avenue toward the design and applications of high-performance SC-PLA-based materials with excellent melt-processability via the generation of unique graft copolymers having long PLLA and PDLA branches.

Review on Spinning of Biopolymer Fibers from Starch.

Increasing interest in bio-based polymers and fibers has led to the development of several alternatives to conventional plastics and fibers made of these materials. Biopolymer fibers can be made from renewable, environmentally friendly resources and can be fully biodegradable. Biogenic resources with a high content of carbohydrates such as starch-containing plants have huge potentials to substitute conventional synthetic plastics in a number of applications. Much literature is available on the production and modification of starch-based fibers and blends of starch with other polymers. Chemistry and structure–property relationships of starch show that it can be used as an attractive source of raw material which can be exploited for conversion into a number of high-value bio-based products. In this review, possible spinning techniques for the development of virgin starch or starch/polymer blend fibers and their products are discussed. Beneficiation of starch for the development of bio-based fibers can result in the sustainable replacement of oil-based high-value materials with cost-effective, environmentally friendly, and abundant products.

Differences in Urinary Bacterial Anti-Adhesion Activity after Intake of Cranberry Dietary Supplements with Soluble versus Insoluble Proanthocyanidins

A number of clinical trials support the use of standardized cranberry supplement products for prevention of urinary tract infections; however, products that are not well-characterized for sufficient levels of bioactive components may contribute to negative clinical outcomes. Cranberry supplements for consumer use are not regulated and can be formulated different ways using cranberry juice, pomace or various combinations. This can lead to consumer confusion regarding effectiveness of individual products. The current study compared two commercial supplement products, one made from cranberry juice extract and the other from a blend of whole cranberry. The influence of formulation and proanthocyanidin (PAC) solubility on in vitro and ex vivo P-fimbriated Escherichia coli bacterial anti-adhesion activity (AAA) was determined. Both supplement products as well as whole, frozen cranberries were chromatographically separated into crude polyphenolic, sugar and acid fractions. In vitro AAA testing of all fractions confirmed that only those containing soluble PACs elicited activity. The cranberry juice extract product had higher soluble PAC content than the whole cranberry blended product, which contained mainly insoluble PACs. The influence of soluble and insoluble PAC levels in each product on the urinary (ex vivo) AAA was determined following ingestion. The juice extract product was associated with significantly higher urinary AAA than that of the whole berry blended product when consumed once daily over the 1-week intervention period.

Thermoplastic Blends Based on Poly(Butylene Succinate-co-Adipate) and Different Collagen Hydrolysates from Tanning Industry\u2014II: Aerobic Biodegradation in Composting Medium

Two different raw hydrolyzed collagens (HCs), by-products of the Tannery industry, were investigated in blends with a bioplastic, as poly(butylene succinate-co-adipate) (PBSA), for the production of thermoplastic items for possible applications in agriculture. Chemical characterization of selected PBSA/HC blends and phytotoxicity assays on garden cress seeds (Lepidium sativum L.), used as spy species, were carried out; in addition, biodegradation and disintegration of specimens were assessed under controlled composting conditions at different temperature (58 and 25 °C). Although one of the HC investigated released sodium chloride in the aqueous extract, all PBSA/HC blends, up to 20 wt.% HC, resulted no-phytotoxic and showed considerable amounts of macro- and micro- nutrients for plants (mainly nitrogen). Regardless the amount added, HCs enhanced the biodegradation rate of PBSA/HC blends in compost at 58 °C compared to pure PBSA; lowering the temperature at 25 °C, as expected, biodegradation rate slightly lowered using the same compost. Most disintegration tests, performed on dog bone samples, corroborated the results of the biodegradation tests, thus suggesting that plastic mixtures could reasonably end their life cycle in a composting facility without decreasing the quality and the safety of the resulting compost. The outcomes achieved encourage the use of raw collagen hydrolysates from tanning industry in the production of PBSA-based thermoplastic blends to produce compostable items (mulching films and/or plant pots) for more sustainable uses in agriculture and/or plant nurseries. In addition, the use of these low-cost by-products can lower the cost of final product and give it fertilizing properties for plants given the presence of organic nitrogen in the hydrolysates.

Development and evaluation of pre and post integration techniques for enhancing drought predictions over India

AbstractAccurate estimation and prediction of drought events are highly essential for implementing effective planning and management strategies to handle this complex natural phenomenon. Application of machine learning algorithms (MLAs) for integrating satellite precipitation products (SPPs), unlike gauge observations, can furnish precise drought estimations. In this study, we have proposed and tested two approaches (pre and post‐integration of SPPs) that deal with the prediction of drought employing 13 MLAs. Three SPPs are integrated under four combinations (involves two and three datasets integration) employing pre and post integration approaches to predict Standardized Precipitation Index and Standardized Precipitation Evapotranspiration Index at various temporal scales (1, 3, 6 and 12‐month). From the overall results, Approach‐2 that involves estimation of drought before integration using MLAs proved effective than Approach‐1 (prediction of drought post‐integration). Neural Networks based Bayesian Regularization (NBR) under three dataset integration outperformed at all temporal scales and climatic zones of India when compared to the other 12 MLAs and two dataset integration combinations. The blended product (NBR) manifested enhancements in statistical results at all temporal scales and climatic zones. European Centre for Medium‐Range Weather Forecasts ReAnalysis (ERA‐5) dataset performed better in predicting drought events in more climatic zones compared to Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks‐Climate Data Record (PERSIANN‐CDR) and Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) when compared against Indian Meteorological Department (IMD) dataset. In contrast, PERSIANN‐CDR proved effective in predicting drought at the country scale. ERA‐5 could be suitable for real‐time drought monitoring and prediction, whereas PERSIANN‐CDR can be used for retrospective drought analysis. The proposed approach and the best‐performed algorithm (NBR) can be extended and applied in any climatic region for enhancing the drought predictions where remotely sensed information are accessible even in regions with finite ground data availability.

Increasing (quantitative) precision: blend production, contexts of alternations, and corpus-linguistic association

This is the video of the talk that was given by Stefan Th. Gries on Tuesday, December 15, 2020

Performance evaluation of NCEP/NCAR reanalysis blended with observation-based datasets for estimating reference evapotranspiration across Iran

Computing crop reference evapotranspiration (ETo) with the FAO Penman-Monteith method (PM-ETo) requires maximum and minimum air temperature, shortwave radiation, relative air humidity, and wind speed that are often unavailable in many places. The use of reanalysis data, which is common in climate studies, represents an alternative to observation data for the mentioned weather variables when are not available. This study focuses on the use of the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR)reanalysis blended with gridded data sets for computing monthly PM-ETo at 43 synoptic stations distributed across Iran. First, with a set of statistical indicators, the reanalysis weather variables required for computing ETo were compared with observation data, where a good match was obtained for solar radiation, maximum temperature, and minimum temperature. In contrast, at most of the studied stations, the reanalysis wind speed and relative humidity showed large errors when compared with observations. The PM-ETo computed with the blended reanalysis data were also compared with those obtained using observations. The results show that the PM-ETo computed from blended reanalysis compares relatively well with the ETo computedfrom observation at most of the studied stations. However, the spatial pattern of performance indicators reveal extremely poor results for the coastal locations of the Caspian Sea in the north and the Persian Gulf and Oman Sea in the south of Iran. Results suggest that, except for wind speed and relative humidity, the blended reanalysis products are suitable forestimatingETo in inland areas of Iran despitesome degree of overestimationat most of the studied stations.

Investigation on Slagging Fouling Potential in Coal Blending for PLTU with PC Boiler with Droptube Furnace Method

The majority of power plants in Indonesia are Coal-Fired Power Plants (PLTU) which using coal as the main fuel. The coal used in the PLTU is coal that has been adjusted to the existing PLTU design. However, coal availability according to the initial design of the PLTU is running low and even almost non-existent. If the coal does not meet the PLTU design specifications is forced to be used as fuel, various problems will arise regarding to the capability and reliability of the power plant itself. Therefore, looking for coal alternatives that have similar specifications to the PLTU design is very important, to get these alternatives can be done by Blending coal from various specifications. The Blending product must be evaluated from various aspects, one of which is slagging and fouling. This research will focus on the aspects of slagging fouling resulting from the Blending of two different coals in terms of characteristics and specifications. Evaluation is carried out by taking samples and tested to make predictions based on AAS and AFT, burning in the Drop Tube Furnace (DTF), and performing SEM and XRD analysis of two coal Blending products. The results obtained are that the A and B Blending products are in an acceptable risk for direct testing on a larger scale (PLTU) or boiler simulator. However, Blending A has a greater potential for further research than Blending product B.

Production of blends of edible oil and carrot carotenoids using compressed propane: Enhancement of stability and nutritional characteristics

This study reports a new procedure to enhance nutritional characteristics of vegetable oils using compressed propane (2 MPa/40 °C). Carotenoids from carrot pulp and peel were incorporated into chia and sesame oils and results were compared to those obtained by Soxhlet extraction. Yields of chia (28.6%), sesame (41.3%), blends of chia oil with extracts of carrot pulp (30.4%) or carrot peel (29.9%), blends of sesame oil with extracts of carrot pulp (42.9%) or carrot peel (43.4%) were satisfactory and similar to those determined by Soxhlet extraction. Carotenoids content in blends varied from 13.8 to 70.9 mg.100 g−1 and β-carotene concentration increased when pressurized propane extraction was employed with grains and carrots. Chia or sesame oils blended with carrot extracts achieved high induction periods. Relevant levels of tocopherols and phytosterols were quantified. The use of structured bed in simultaneous extraction of oilseeds and carrots was effective, resulting in a high value-added product.

The study of the fatty acid composition of camelina oil obtained by cold pressing

Non-traditional oilseeds include camelina seeds, which are widely known in the global production of oils and blends. The seeds of this plant are a source of polyunsaturated fatty acids, including linoleic and linolenic acids. A distinctive feature of the seeds of this culture is the oil content–40% and crude protein–30%. The object of the study was oil obtained by cold pressing and the seeds of camelina of the Penzyak variety. Samples were obtained in an experimental installation under the following conditions: a pressing chamber annular clearance was 0.3 mm; the screw rotational speed was 160 rpm at a temperature of 336 K. The fatty acid composition of the camelina oil sample was determined by gas-liquid chromatography on a Chromotech 5000. The presented results of camelina oil studies by fatty acid composition show that unsaturated fatty acids ☐-9 prevail in the test oil. It was determined that fatty acids of groups 18 and 16, 20 predominate in camelina oil. At the next work stage, studies were carried out on the chemical composition of the sample, as a result of which it was found that camelina oil contains 4 vitamins (vitamins A, K, ☐, ☐ + ☐ and ☐-tocopherols) and traces of vitamin K, the purpose of which is to provide increased biological and nutritional value of the product.

The Development of Blended Learning Courses Development of Education and Training Programs State University of Jakarta

This research aims to develop a blended learning products to facilitate students in the course of the Development of Education and Training Programs in the environment of Educational Technology study programs, Jakarta State University. The research methods carried out are included in the Research and Development method. The research and development method adapted using the Dick and Carey system-based model and adding the ILDF (Integrated Learning Design Framework) model in step 7th of the Dick and Carey model. While the ILDF (Integrated Learning Design Framework) model is used as a product development model with steps, namely 1) Exploration, 2) Compilation, 3) Evaluation. Evaluations were carried out by expert reviews and one-to-one and small group user trials. The results of the three experts assessment showed 3,1 and the user trial showed 3,5. The development of blended learning courses The Development of the Training Program can be accessed on the moodle portal of Educational Technology and is expected to be able to facilitate the learning needs of students in the blended learning process especially in online learning (asynchronous).

Benefits of Disposing Polyhydroxybutyrate-Co-Hydroxyvalerate (PHBV) Blends in Soil, as Alternative for Low Density Polyethylene

The use of synthetic plastics generates environmental impacts due to their low biodegradability and inadequate disposal. One of the alternatives to minimize this problem is the use of biodegradable polymers and/or the production of blends with desired industrial and eco-friendly characteristics. The biodegradation of PHBV (Poly (Hydroxybutyrate-co-Hydroxyvalerate)), LDPE (Low Density Polyethylene) and LDPE / PHBV (70/30) blends in soil column was evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), and mass loss. Through SEM it was possible to observe micro morphological changes on the surface of the PHBV and the blends, in accordance with the mass loss variation. PHBV samples showed a reduction of 43.9 % and the blend had a reduction of 15.7 %, during their biodegradation process. FTIR analysis revealed that the crystallinity of the polymeric materials changed, suggesting the biodegradation of these films. Soil samples were characterized by determination of pH, organic matter (%), moisture (%), and CFU of the microbial community. The blend was susceptible to soil microbial activity, with significant changes in its micro morphology. The used 70/30 ratio (LDPE/ PHBV) showed susceptibility to soil microorganisms, favoring the increase of its microbial community. The use of polymeric blends also favors the reduction of the amount of polymers present in the environment because some of them are biodegradable.

The influence of complex additives based on calcined clays and carbonate fillers on hydration products composition of blended cement stone

One of the most effective and recognizable way to solve energy and resource consumption problems in cement industry is the development of blended Portland cement with different combinations of mineral additives. The development of complex additives based on combination of calcined clays and limestone is one of the promising directions. The aim of this work was to study the influence of complex additives based on calcined kaolinitic clay with kaolinite content of 80 % and limestone with calcite content of 99 % on the blended cement stone hydration products at the age of 28 days. Using X-ray diffraction and differential scanning calorimetry the composition of blended cement stone hydration products was studied. It is established that the introduction of 20 % of the complex additive based on calcined clay and limestone leads to a significant decrease of the portlandite content, increase in the number of new growths in form of low-calcium hydrosilicates and calcium hidrocarboalumosilicates, stabilization of ettringiteand calcium hydrocarbosilicates in amorphous phase, that significantly increases the compressive strength. This effect was amplified due to the additional alumina provided by calcined clay reaction.

Operational Control Method for Managing Homogeneity of Multicomponent Mixtures Based on Optoleptic Photosensitive Scanning of their Surface during Mixing

To control and manage the degree of homogeneity of the mixture, an optoleptic method of photosensitive scanning of the mixture surface has been developed, which makes it possible to efficiently control and manage the homogenization of the mixture during its production. To improve the accuracy of the method in order to increase the contrast during photosensitive scanning of the surface, it is proposed to introduce a lumogen indicator into the mixture. An example of the application of the proposed method in the production of magnesial cement blends for the preparation of solutions for cementing casing strings of oil and gas wells is considered.