4 research outputs found
Analysis of the Interaction Between Properties and Microstructure of Construction Ceramics
We have defined the basic properties of ceramic bricks for various purposes. The microstructure and phase composition of ordinary, facing and clinker bricks were investigated. We have established the interrelation between the microstructure and phase composition of the examined materials and water absorption, mechanical strength at compression, and frost resistance. The research results allowed us to identify patterns in the formation of a ceramic sherd and explain the physical-chemical processes during sintering.It was established that ordinary brick mostly contains the thermally altered clay substance with a low amount of the glass-phase. Given the above, due to the incomplete liquid-phase sintering, the ordinary brick has high water absorption values (10‒14 %) at low strength (7.5‒12.5 MPa).Facing brick has the more developed glass-phase, which firmly binds the crystalline phase. The latter is represented by such minerals as β-quartz, microcline, albite, mullite, etc. The main task in the facing brick production is to ensure the optimal dispersion of starting raw materials and to achieve even distribution of minerals throughout the entire volume of the product.Clinker brick has a more complex mechanism of sintering because when using the starting particulate mass, it is required to obtain a dense homogeneous structure of products. The main features of the ceramic mass are the introduction to its composition of emaciated additives that would ensure the resistance of products against deformation during annealing, and marshes, which should ensure the intensive liquid-phase sintering at annealing. When annealing such articles, it is necessary to select the proper temperature-time mode, which would match the sintering interval of the basic clay material. This is required to ensure that, on the one hand, a strong dense structure of the product is obtained, with a water absorption of 4‒5 %, and, on the other hand, that such kinds of defects as deformation, cracking, «over-annealing», swelling, etc. are avoided.Research results could be applied under industrial conditions at enterprises in order to control product quality and eliminate possible causes of defects related to violation of the technological production mode
Absorption- and Excitation-Modulated Luminescence of Pr3+, Nd3+, and Lu3+ Compounds with Dianions of Tetrafluoroterephthalic and Camphoric Acids
Development of Object State Evaluation Method in Intelligent Decision Support Systems
Accurate and objective object analysis requires multi-parameter estimation with significant computational costs. A methodological approach to improve the accuracy of assessing the state of the monitored object is proposed. This methodological approach is based on a combination of fuzzy cognitive models, advanced genetic algorithm and evolving artificial neural networks. The methodological approach has the following sequence of actions: building a fuzzy cognitive model; correcting the fuzzy cognitive model and training knowledge bases. The distinctive features of the methodological approach are that the type of data uncertainty and noise is taken into account while constructing the state of the monitored object using fuzzy cognitive models. The novelties while correcting fuzzy cognitive models using a genetic algorithm are taking into account the type of data uncertainty, taking into account the adaptability of individuals to iteration, duration of the existence of individuals and topology of the fuzzy cognitive model. The advanced genetic algorithm increases the efficiency of correcting factors and the relationships between them in the fuzzy cognitive model. This is achieved by finding solutions in different directions by several individuals in the population. The training procedure consists in learning the synaptic weights of the artificial neural network, the type and parameters of the membership function and the architecture of individual elements and the architecture of the artificial neural network as a whole. The use of the method allows increasing the efficiency of data processing at the level of 16–24 % using additional advanced procedures. The proposed methodological approach should be used to solve the problems of assessing complex and dynamic processes characterized by a high degree of complexity
Facile One-Pot Parallel Synthesis of 3‑Amino-1,2,4-triazoles
A 1,2,4-triazole
motif is present in numerous commercialized and
investigational bioactive molecules. Despite its importance for medicinal
chemistry, there is a lack of convenient combinatorial approaches
toward this molecular core. Herein, we present a synthetic strategy
suitable for the quick preparation of a library of structurally diverse
1,2,4-triazoles in a one-pot setting. The key steps include the formation
of thioureas followed by <i>S</i>-alkylation using 1,3-propane
sultone and consecutive ring closure leading to the desired 1,2,4-triazoles.
Parallel synthesis yields thousands of 1,2,4-triazoles in a cost-
and time-efficient manner from commercially available chemicals