The use of the correlation method in evaluating the accuracy characteristics of precision instruments

Evaluations of the accuracy characteristics of precision instruments obtained by the correlation method and the three-cornered hat method are compared. It is shown that the resulting evaluations are the same, and the correlation method is easier to implement and provides a more accurate assessment. A technique is proposed for evaluating the impact of the correlation of meter errors in the implementation of the correlation method. The results of natural and computational experiments (in relation to the measurement of the pulse sequence period) have shown that there is almost no correlation of the meter errors.     

Two-level calculation method for tribojoints made of dispersion-reinforced composites: Part 2

Meshing of a straight spur gear made of a low-modular dispersion-reinforced material with a metal pinion has been simulated using a two-level calculation method for tribojonts. The values of the elastic displacements and the face contact ratio in the tooth pitch and top points were compared. A nonlinear dependence has been established of the contact and flexural stiffness values ν. Poisson’s ratio ν. The stiffness was found to increase in the region of negative v values, which is characteristic of auxetic materials.     

Soft sensor for continuous product quality estimation (in crude distillation unit)

Due to the strict norm requirements of keeping products in crude refining units within specifications, laboratory testing and quality control of the products are necessary. Given this reason, virtual soft sensor for continuous quality estimation of light naphtha as the crude distillation unit (CDU) product was developed. Experimental data included available continuous measurements of CDU process streams (temperatures, pressures and flowrate) and laboratory analyses undertaken twice a day. The results are soft sensor models for light naphtha vapor pressure (RVP) estimation.Soft sensor models have been developed conducting multiple linear regression analysis and using neural network-based models such as LNN, MLP and RBF. Considering statistical and sensitivity analysis, the best results for both oils were obtained with MLP and RBF neural networks. The results show possible application of the soft sensor models for estimating light naphtha RVP as an alternative for laboratory testing.     

Interaction of humic acid salts with drug preparations

The use of natural polymers that form complexes with drug preparations is promising in the development of drugs of new generation. The possibility of complex formation on the interaction of humic acid salts with papaverine, benzohexonium, and B-group vitamins was demonstrated by calorimetric and potentiometric titration. These interactions can occur between the charged groups of a humic acid macroanion and the positively charged centers of drug molecules. The degree of binding of drug preparations by a natural polymer macromolecule can be determined by the charge and the structure of their molecules.     

Modification of the surface of sheet glass (A Review)

The paper contains an analysis of the literature data on modification of the surface of sheet glass in order to impart heat-shielding, conducting, hydrophobic, x-ray-shielding, decorative, and other properties to glass. Various industrial and scientific entities engaged in production and development of modifying coatings are described. A classification of film coatings is offered, and the main production methods are considered. The effect of various factors on film coatings is analyzed. Translated from Steklo i Keramika, No. 4, pp. 3–7, April, 2000.     

Construction materials based on cullet

The results of the development of decorative, heat-insulating and soundproof construction materials based on glass cullet are discussed. The service parameters of the samples are determined and the optimum technological production schemes are developed. Translated from Steklo i Keramika, No. 1, pp. 4–6, January, 1999.