PRECISION, STABILITY ANALYSIS OF THE CRANKSHAFT GRINDING TECHNOLOGICAL PROCESS

Introduction. The article is devoted to the problem of the crankshafts quality of automotive tractor engines on the example of YaMZ - 238NB engines. Despite years of experience in the repair industry to implement the technological process of the crankshafts grinding during their restoration, the quality of its implementation is not sufficient. Therefore, for reducing errors in restoring crankshafts, as well as in any other parts, it is possible only if the reasons for their occurrence are promptly identified. The purpose of the research is to identify the reasons of the errors in the process of grinding crankshafts for repair dimensions according to the results of technical control and observation of the technological process.Materials and methods. The methodological basis for experimental and theoretical research is a system analysis. The structural and functional representation of the object is also used for research, and the model for the analysis of the grinding process serves as the basis for the  decomposition.Results. While analyzing the measurements results of the rod necks connection and polishing for repair dimensions, the transformed experimental-statistical method is applied. The peculiarity of the method consists in the algebraic transformation of the calculation algorithm, which is reduced to simple formulas for semi-finished products and which makes it easy to program calculations on the  computer. In addition, the order of processing the number of obtained numerical values and construction of distribution curves is stated for estimating the correspondence between the probability of the experimental distribution and the theoretical distribution.Discussion and conclusions. The implementation of the algorithm for calculating the accuracy and stability for the technological process of grinding the crankshafts during their restoration would reduce the error value. Moreover, the reduction of errors during the process of crankshafts restoration would improve the quality of repair, thus prolonging the crankshaft serviceability

Complexation and Sorption of Europium(III) Ions onto Clay Minerals in the Presence of Fulvic Acids

The effect of fulvic acids (FA) on the sorption of europium(III) ions from aqueous solution onto Gluhovsky kaolinite and Cherkasky montmorillonite was studied. Sorption of Eu(III) ions onto the mineral surface increased as the pH value of the aqueous solution increased from 1 to 8, but decreased when fulvic acids were present in solution. Over the concentration range studied, Eu(III) ion sorption occurred as free europium ions which were not bound as fulvate complexes. At pH ≥ 6 and at high Eu(III) ion concentrations (> 200 μmol/dm 3 ), the increase in europium ion adsorption in the presence of fulvic acids was twice that observed in their absence. This demonstrated the formation, under these conditions, of a two-nucleus complex with a chain of the type sorbent-Eu-FA-Eu. In natural waters at pH > 6, Eu(III) exists mainly in the form of soluble complexes where binding occurs via the oxygen atoms of the phenol groups in FA

Influence of Humic Substances on the Sorption Interactions between Lanthanide and Actinide Ions and Clay Minerals

Lanthanide (Eu, Nd, Gd) and actinide (Th, U) adsorption in a system consisting of fulvic acid, metal ions and clay minerals (montmorillonite, kaolinite, illite) was studied as a function of pH, metal ion concentration and fulvic acid concentration using spectrophotometric analysis and 152 Eu tracer methods. Increasing metal ion adsorption on to the clay minerals was observed when humic substances were present in the system. The bridging of polyvalent metal ions between clay minerals and humic substance complexes was proposed as the possible adsorption mechanism