The Effect of Elemental Composition and Nanostructure of Multilayer Composite Coatings on Their Tribological Properties at Elevated Temperatures

The chapter discusses the tribological properties of samples with multilayer composite nanostructured Ti-TiN-(Ti,Cr,Al,Si)N, Zr-ZrN-(Nb,Zr,Cr,Al)N, and Zr-ZrN-(Zr,Al,Si)N coatings, as well as Ti-TiN-(Ti,Al,Cr)N, with different values of the nanolayer period λ. The relationship between tribological parameters, a temperature varying within a range of 20–1000°C, and λ was investigated. The studies have found that the adhesion component of the coefficient of friction (COF) varies nonlinearly with a pronounced extremum depending on temperature. The value of λ has a noticeable influence on the tribological properties of the coatings, and the nature of the mentioned influence depends on temperature. The tests found that for the coatings with all studied values of λ, an increase in temperature first caused an increase and then a decrease in COF

The effect of local immunity on gastric cancer prognosis

Aim. To study the state of local immunity in patients with gastric adenocarcinoma. Materials and methods. From 2017 to 2018, 45 previously untreated patients with gastric adenocarcinoma (25 with stage IIII, 20 with stage IV) received surgical/combined treatment or chemotherapy, respectively, at the Blokhin Scientific Research Center of Oncology. Tumor tissue was taken before treatment. By using flow cytometry there were evaluated the percentage of tumor tissue infiltration by lymphocytes (CD45+CD14-TIL); T cells (CD3+CD19-TIL); B cells (CD3-CD19+TIL); NK cell (CD3-CD16+CD56+TIL); effector cells CD16 (CD16+Perforin+TIL) and CD8 (CD8+Perforin+TIL) with their cytotoxic potential active CD16TIL and active CD8TIL; subpopulations of regulatory T cells NKT cells (CD3+CD16+CD56+TIL), regulatory cells CD4 (CD4+CD25+CD127-TIL) and CD8 (CD8+CD11b-CD28-TIL). The prognostic value of immune cells for overall survival (OS) and progression-free survival (PFS) was assessed. Results. A favorable prognosis factor for progression-free survival in patients with local and locally advanced forms of gastric cancer was an increase in the number of CD3-CD19+TIL (HR 0.862, 95% CI 0.7820.957, p=0.005), and an unfavorable prognosis was an increase in NK cells (CD3-CD16+CD56+TIL); HR 1.382, 95% CI 1.0871.758, p=0.008. The negative effect of the relative content of NK cells (CD3-CD16+CD56+TIL) and NKT cells (CD3+CD16+CD56+TIL) on OS of patients with metastatic gastric cancer noted (HR 1.249, 95% CI 0.9971.564, p=0.053; HR 1.127, 95% CI 1.0251.239, p=0.013). At the same time, an increase in the percentage of tumor tissue infiltration by lymphocytes (CD45+CD14-TIL) and an increase in the age of patients (HR 1.005, 95% CI 1.0021.008, p=0.003; HR 1.098, 95% CI 1.0311.170, p=0.004) reduce the incidence of PFS in patients with metastatic gastric carcinoma. Conclusion. Indices of local immunity can serve as additional prognostic factors for gastric carcinoma

Analysis of risk and threats to financial performance of enterprises in agro-industrial complex

The article discusses the risk assessment methods of financial performance of an enterprise. The essence of the main risks typical in enterprises of agro-industrial complex is described, sources of risk and factors affecting the financial performance are identified. A logical and probabilistic model of the risk of financial performance of an enterprise is suggested; factors and events that initiate the loss of profit, a decrease in sales revenues and an increase in the costs of enterprises in the agro-industrial complex are revealed. A method for calculating the significant values of risk probability and security areas for the formation of the financial performance of an enterprise is presented. An algorithm for calculating the dependencies was developed and it makes it possible to assess the critical values of indicators of financial and economic activity of an enterprise and the level of risk and threats to financial performance. The expediency of use of the authors’ algorithm in order to optimize the amount and structure of costs and capital. It was stated that the suggested approach allows to monitor continuously the magnitude of risk and threats, to evaluate the effectiveness of measures which reduce the risk of having undesirable financial performance in an enterprise

Multilayer composition coatings for cutting tools: formation and performance properties

The paper considers the concept of a multi-layer architecture of the coating in which each layer has a predetermined functionality. Latest generation of coatings with multi-layered architecture for cutting tools secure a dual nature of the coating, in which coatings should not only improve the mechanical and physical characteristics of the cutting tool material, but also reduce the thermo-mechanical effect on the cutting tool determining wear intensity. Here are presented the results of the development of combined methods of forming multi-layer coatings with improved properties. Combined method of forming coatings using a pulsed laser allowed reducing excessively high levels of compressive residual stress and increasing micro hardness of the multilayered coatings. The results in testing coated HSS tools showed that the use of additional pulse of laser processing increases tool life up to 3 times. Using filtered cathodic vacuum arc deposition for the generation of multilayer coatings based on TiAlN compound has increased the wear-resistance of carbide tools by 2 fold compared with tool life of cutting tool with commercial TiN coatings. The aim of this study was to develop an innovative methodological approach to the deposition of multilayer coatings for cutting tools with functional architectural selection, properties and parameters of the coating based on sound knowledge of coating failure in machining process