Kinematic Support of a Regular Micro-Relief of a Spherical of a Workpiece By An Embracing Milling

The possibilities of modification of spherical surfaces by cutting and ion-plasma processing with the purpose of improving the quality of machine parts are considered. An analysis of the kinematic features of the treatment of spherical surfaces by a rotating tool at a high cutting speed and the formation of a cutting surface is given. The results of experimental studies of the physical characteristics of the shear layer, microrelief, and microhardness of the resulting surface of the component are presented, including after coating with TiN by an ion-plasma method on a vacuum installation, confirming a decrease in the height of irregularities to Ra 0,6 / 1,2 ?m and increasing microhardness in 1,5 / 3 times in comparison with the traditional methods of obtaining spherical surfaces

Tribological behavior of 316L stainless steel reinforced with CuCoBe + diamond composites by laser sintering and hot pressing: a comparative statistical study

The aim of this work was to perform a statistical analysis in order to assess how the tribological properties of a laser textured 316L stainless steel reinforced with CuCoBe - diamond composites are affected by diamond particles size, type of technology (laser sintering and hot pressing) and time of tribological test. The analysis started with the description of all response variables. Then, by using IBM® SPSS software, the Friedman’s test was used to compare how the coefficient of friction varied among samples in five-time points. From this test, results showed that there was no statistically significant difference in the coefficient of friction mean values over the selected time points. Then, the two-samples Kolmogorov-Smirnov (K-S) test was used to test the effect of the diamond particles size and the type of technology on the mean of the coefficient of friction over time. The results showed that, for both sintering techniques, the size of the diamond particles significantly affected the values of the coefficient of friction, whereas no statistical differences were found between the tested sintering techniques. Also, the two-way ANOVA test was used to evaluate how these factors influence the specific wear rate, which conducted to the same conclusions drawn for the previous test. The main conclusion was that the coefficient of friction and the specific wear rate were statistically affected by the diamond particles size, but not by the sintering techniques used in this work.This work was supported by FCT national funds, under the national support to R&D units grant, through the reference projects UIDB/04436/2020 and UIDP/04436/2020. Additionally, this work was supported by FCT with the reference projects UIDB/00319/2020 and PTDC/CTM-COM/30416/2017

Elliptic hypergeometry of supersymmetric dualities II. Orthogonal groups, knots, and vortices

We consider Seiberg electric-magnetic dualities for 4d $\mathcal{N}=1$ SYM theories with SO(N) gauge group. For all such known theories we construct superconformal indices (SCIs) in terms of elliptic hypergeometric integrals. Equalities of these indices for dual theories lead both to proven earlier special function identities and new conjectural relations for integrals. In particular, we describe a number of new elliptic beta integrals associated with the s-confining theories with the spinor matter fields. Reductions of some dualities from SP(2N) to SO(2N) or SO(2N+1) gauge groups are described. Interrelation of SCIs and the Witten anomaly is briefly discussed. Possible applications of the elliptic hypergeometric integrals to a two-parameter deformation of 2d conformal field theory and related matrix models are indicated. Connections of the reduced SCIs with the state integrals of the knot theory, generalized AGT duality for (3+3)d theories, and a 2d vortex partition function are described.Comment: Latex, 58 pages; paper shortened, to appear in Commun. Math. Phy