Abstract. The research of the structure formation process on a nanolevel of the samples of hydrated Portland cement compositions containing the modifying additives has been conducted with the help of small angle neutron scattering method. Carbonate and aluminum alkaline slimes as well as the complex additives containing surfactants were used as additives. The influence of slimes and surfactants on structural parameters change of Portland cement compositions of the average size of the disseminating objects, fractal dimension samples is considered. These Portland cement compositions are shown to be fractal clusters.
Abstract. Growing volumes of construction result in the rising demand for highquality wall materials and products, growing relevance of availability of resource and raw-material base of natural and industrial products for the construction industry. Structural, physical and mechanical qualities of these products can be improved through systematical selection of compositions based on natural and raw materials, including nano-scale products. The goal of this paper is to provide rationale for structure formation mechanisms of multicomponent materials (silica-lime, silicate, cement materials), with the possibility of using nano-scale products in their production. The primary mechanism of directed structure formation at the interface boundaries of binders are nano-and ultra-disperse particles with high absorption and adhesion properties, which are primarily intended to strengthen the contact area (one of the key structural units of multicomponent binders). The knowledge of genesis, chemical, mineralogical, and phase compositions, as well as specific features of formation of nano-technological raw materials, enables optimization of construction product properties. Using the small-angle neutron scattering method, we identified granulometric and surface properties of a series of nano-technological products (binary and sludge) and materials where such products are used, which enabled us to design optimal mixture compositions and parameters of pressing operations.
The results of studies to determine the optimal level of input of a complex of macronutrients in protein-vitamin-mineral supplements are given, their influence on digestibility, the use of feed nutrients, hematological parameters, growth and development of young pigs are studied. Feeding in the composition of grain-cereal rations of 12.5% protein-vitamin-mineral supplements with elevated levels of Fe, Cu, Zn, Mn, Co, J, Se contributes to an increase in pigs by 5.5-8.5% of daily gains, by 8-12 days of early maturity, by 0.28-3.35% slaughter yield, by 12.1-19.5% meat ratio. Bringing microelements to the optimum level in protein-vitamin-mineral supplements composition contributes to a significant increase in the digestibility of organic matter and raw fat. Reducing the level of trace elements by 30% hinders the process of digestion of feed. The use of 12.5% protein-vitamin-mineral supplements with a high content of trace elements in grain-cereal rations of pigs has a significant effect on the degree of utilization of nitrogen, calcium, phosphorus, iron, copper, zinc, manganese. When protein-vitamin-mineral supplements are fed with an optimal level of trace elements in the composition of diets of young pigs, it contributes to an increase in the number of erythrocytes, hemoglobin, total protein and its fractions. A 30% increase in the level of trace elements in protein-vitamin-mineral supplements provides for obtaining high-energy meat with a high content of dry matter, protein and fat. The inclusion in the composition of grain-cereal rations of protein-vitamin-mineral supplements with the optimal level of trace elements helps to reduce the cost of feed by 5.2-7.8%, to obtain 3.8 kg of additional growth.
The durability of cement-containing building materials, like the cement stone itself, depends on their moisture resistance, frost resistance, and corrosion resistance. All these properties are determined not only by the composition of the initial clinker, but also by the structural organization at the micro-and nanoscale of hydrated Portland cement. In this work, the structural parameters of hydrated Portland cement compositions at the nanoscale level were determined by the method of small-angle neutron scattering: the size distribution of nanoparticles of calcium silicate hydrate, the average radius of nanoparticles, and fractal dimension. It is shown that the introduction of modifying nanoadditives into Portland cement affects the structural parameters of the cement stone. The following nanoadditives were used: of artificial (alpha aluminium oxide, gamma aluminum oxide) and of technogenic (carbonate and alumo-alkaline sludges) origin, as well as complex nanoadditives containing surfactants. Changes in structural parameters of Portland cement with nanoadditives in the process of hydration are traced. It is shown that the use of nanoadditives makes it possible to control the process of formation of the structure of hydrated Portland cement on the nanoscale level, to directly influence the values of structural parameters and, ultimately, to the properties of cement stone.
The article discusses the use of the student's cumulative assessment system of academic progress as a valid element of e-learning in universities. Today, online learning is becoming mainstream. Training on online platforms is convenient and interesting, however, it is not acceptable for all students due to the need to conclude network contracts or lack of regulations on how to recalculate the results of online training at the university, etc. Using the cumulative system becomes the mechanism that solves the issue of e-learning at universities, including using distance learning technologies, without cooperating with the online platforms. The suggested approach is a new one. The purpose of the article is to study the electronic information and educational environment of the university to monitor the students’ progress. The recommended assessment means the cumulative assessment, which reflects the consistency of knowledge of the student as a participant in the training process. The recommended assessment is suggested by the information system and is calculated using a mathematical model that considers all types of student work. The assessment becomes the main one and should be considered during an interim assessment. The study of the recommended assessment formation uses the methods of mathematical statistics, data grouping, associative data sets, data verification, database manipulation. The authors also give an optimal strategy for storing large amounts of data based on minimizing their volume while maintaining the necessary access speed.
To date, there are not enough tools by which the high school would target a graduate to work in a particular company. Moreover, various bodies, even public ones, periodically request educational establishments to submit proposals for improving the staff selection and training practices. This is the relevance of our research. This article deals with a tool that allows an employer to reasonably select a university graduate who most fully meets the requirements of a particular company. Such a tool should be a mechanism for integrating the regional competence profile for the graduates. This mechanism can be implemented through the upload of students' academic project (term theses, projects, design graphics and research works, graduate thesis, etc.) in an electronic information system. In addition to the student’s study, the employer is offered access to abstracts, which contain a list of professional competences acquired by the student during the implementation of these studies. In addition, the employer is given the opportunity to write a comment regarding the relevance of the work and their final assessment, as well as suggest their own topic in the abstract. This will allow employers to track the professional growth of students they are interested in. In high school, this mechanism will affect the personal rating of the teacher - the head of the student’s academic work. Thus, the teacher motivated to increase their rating will be forced to make contact with employers through the online information environment to obtain relevant topics offered by them, and to improve the quality of students’ projects. The purpose of this study is to create a mechanism for integrating a regional competence profile of a graduate into a real educational process throughout the student’s entire learning path. The result of the study is a mechanism for the teacher to continuously have in mind the requirements of the regional labor market and design an in-demand competence profile throughout the student’s entire learning path. The study was carried out using the method of analysis, management in the chain "student-teacher-employer" on the basis of feedback, methods of observation and experiment.
The papers on contact-condensing (non-autoclave) curing of silicate materials point at the expediency of technology development. Non-autoclave silicate products of M 100 … 300 grades can be used in low-rise and individual housing construction. The complexity of practical implementation of the technology associated with the processes occurring in the field of highly dispersed phases requires research on micro capsulation of hydro silicate binder, in particular, the maintenance of its properties in technological redistribution. High surface energy of newgrowth causes particle clustering. It is desirable to obtain aggregates characterized by the lowest energy of their total intercrystallite interaction. Main mechanism of directed structure formation at the boundaries of the sections of the given binder is ultradisperse particles with a high adsorption capacity and adhesive ability, the main purpose of which is to strengthen the contact zone. The novelty of the proposed solutions lies in the fact that contact formation zone is presented as a multilayer system having different rheological characteristics. The study and description of contact-condensing processes occurring in unstable hydrosilicate systems as well as the sol-gel technologies are the important aspects in the foundations development of modern material science, the creation of materials and new generation products.
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