33S and 13C hyperfine interactions in the single-crystal EPR spectra of 63Cu(II) bis(diethyl-dithiocarbamate)

A detailed analysis of the 33S and 13C ligand hyperfine interactions observed in the single-crystal EPR spectra of 63Cu-labelled copper(II)bis(diethyl-dithiocarbamate), diamagnetically diluted by the corresponding Ni(II)-complex, is reported. The 33S hyperfine tensors are nearly axial symmetric; the unique axes are found to lie along the CuS bond directions. The observation of two different sets of 33S splitting parameters is in agreement with the presence of a rhombic distortion of the planar ligand field. The 13C hyperfine tensor is isotropic within experimental error. The bonding situation of the electronic ground state is discussed. In order to explain the unusually small linewidths observed the electron spin-lattice relaxation time was measured in the temperature-range 2 ≤ T ≤ 77 K. © 1977

Plasma technology for increase of operating high pressure fuel pump diesel engines

This paper presents the results of a change in the service life of high pressure fuel pumps of diesel engines on the working surface of the plunger which a wear resistant dielectric plasma coatings based on silicon oxycarbonitride. Such coatings possess high wear resistance, chemical inertness and low friction

Assessing the Impact of RPA on the Modern Economic System

The study examines the iss ues of assessing the impact of the technology of robotization and automation of business processes on the modern economic system and on enterprises in the field of high information technologies. The hypothesis is put forward, according to which the introduction of RPA technologies can significantly reduce the costs of companies for the organization and implementation of manual labor by delegating such labor to the described technologies. The relevance of the research is due to the growing influence of RPA technologies on the business processes of companies, the structure of their costs and revenues, as well as the outstanding financial results of companies that have implemented business process automation technologies. The purpose of the study is to evaluate the effectiveness and expediency of the use of robotization of business processes by domestic companies. During the analytical activity, a strong relationship was revealed between the growth of the RPA technology market and the dynamics of the financial assessment of companies related to the field of business process automation. A sociological survey was also conducted, the purpose of which was to find out the level of popularity of RPA among people, their opinions about automation technologies, confidence in such services and the desire to use the technologies under study in their own lives. The research uses general scientific methods: analysis, synthesis, sociological survey, correlation analysis, as well as a systematic approach. As a result of the study, the hypothesis was confirmed, proving that modern companies should implement RPA technologies in order to withstand competition by reducing costs. The sociological survey showed that the vast majority of respondents are familiar with RPA technologies and trust them to a certain extent. A large percentage of respondents stated their readiness to use automation, which gives companies access to new horizons of opportunities due to the likely increase in people’s confidence in automation tools. Recommendations were given to domestic companies on the introduction of robotics into the business structure and the prospects for improving labor productivity at all levels of the company were described. The above measures may also be the result of changes in the company’s recruitment policy and the system of training and introduction of new personnel

Electron spin-lattice relaxation of Cu(II) in Zn(II)-bis(diethyl-diselenocarbamate) single crystals

Using the pulse saturation method the spin-lattice relaxation rate T1 -1 for Cu(II) in Zn(II)-bis(diethyl-diselenocarbamate) was measured in the temperature range 1.5 < T < 33 K. From the T-dependence of T1 -1 the Debye temperature of the host crystal was obtained. The angular dependence of T1 -1 as well as the influence of the hyperfine interaction on T1 -1 are discussed. © 1974

Surface hardening of cutting elements agricultural machinery vibro arc plasma

At present, the state technical policy aimed at the modernization of worn equipment, including agriculture, based on the use of high-performance technology called nanotechnology. By upgrading worn-out equipment meant restoring it with the achievement of the above parameters passport. The existing traditional technologies are not suitable for the repair of worn-out equipment modernization. This is especially true of imported equipment. Out here alone - is the use of high-performance technologies. In this paper, we consider the use of vibro arc plasma for surface hardening of cutting elements of agricultural machinery

On the roots of the Poincare structure of asymptotically flat spacetimes

The analysis of vacuum general relativity by R. Beig and N. O Murchadha (Ann. Phys. vol 174, 463 (1987)) is extended in numerous ways. The weakest possible power-type fall-off conditions for the energy-momentum tensor, the metric, the extrinsic curvature, the lapse and the shift are determined, which, together with the parity conditions, are preserved by the energy-momentum conservation and the evolution equations. The algebra of the asymptotic Killing vectors, defined with respect to a foliation of the spacetime, is shown to be the Lorentz Lie algebra for slow fall-off of the metric, but it is the Poincare algebra for 1/r or faster fall-off. It is shown that the applicability of the symplectic formalism already requires the 1/r (or faster) fall-off of the metric. The connection between the Poisson algebra of the Beig-O Murchadha Hamiltonians and the asymptotic Killing vectors is clarified. The value H[K^a] of their Hamiltonian is shown to be conserved in time if K^a is an asymptotic Killing vector defined with respect to the constant time slices. The angular momentum and centre-of-mass, defined by the value of H[K^a] for asymptotic rotation-boost Killing vectors K^a, are shown to be finite only for 1/r or faster fall-off of the metric. Our center-of-mass expression is the difference of that of Beig and O Murchadha and the spatial momentum times the coordinate time. The spatial angular momentum and this centre-of-mass form a Lorentz tensor, which transforms in the correct way under Poincare transformations.Comment: 34 pages, plain TEX, misleading notations changed, discussion improved and corrected, appearing in Class. Quantum Gra

Aerosol fluxing in electro arc metallization

© Published under licence by IOP Publishing Ltd. The main structural and technological factors of electric arc metallizers, which significantly affect the quality of their operation, are considered. The results of experimental studies on the adhesion strength, porosity, microhardness and comparative wear resistance of coatings obtained by electroarc metallization are presented. Optimal modes of coating with electroarc metallization are determined. It is established that the use of aerosol fluxing during electric arc metallization provides an increase in adhesion-cohesive strength by 25 ⋯ 30%, an increase in microhardness to 40%, a decrease in porosity by 20 ⋯ 25%

On Nonperturbative Calculations in Quantum Electrodynamics

A new approach to nonperturbative calculations in quantum electrodynamics is proposed. The approach is based on a regular iteration scheme for solution of Schwinger-Dyson equations for generating functional of Green functions. The approach allows one to take into account the gauge invariance conditions (Ward identities) and to perform the renormalization program. The iteration scheme can be realized in two versions. The first one ("perturbative vacuum") corresponds to chain summation in the diagram language. In this version in four-dimensional theory the non-physical singularity (Landau pole) arises which leads to the triviality of the renormalized theory. The second version ("nonperturbative vacuum") corresponds to ladder summation and permits one to make non-perturbative calculations of physical quantities in spite of the triviality problem. For chiral-symmetrical leading approximation two terms of the expansion of the first-step vertex function over photon momentum are calculated. A formula for anomalous magnetic moment is obtained. A problem of dynamical chiral symmetry breaking (DCSB) is considered, the calculations are performed for renormalized theory in Minkowsky space. In the strong coupling region DCSB-solutions arise. For the renormalized theory a DCSB-solution is also possible in the weak coupling region but with a subsidiary condition on the value of $\alpha$.Comment: 31 pages, Plain LaTex, no figures. Journal version: some discussion and refs. are adde

USp(2k) Matrix Model: Nonperturbative Approach to Orientifolds

We discuss theoretical implications of the large k USp(2k) matrix model in zero dimension. The model appears as the matrix model of type IIB superstrings on a large $T^{6}/Z^{2}$ orientifold via the matrix twist operation. In the small volume limit, the model behaves four dimensional and its T dual is six-dimensional worldvolume theory of type I superstrings in ten spacetime dimensions. Several theoretical considerations including the analysis on planar diagrams, the commutativity of the projectors with supersymmetries and the cancellation of gauge anomalies are given, providing us with the rationales for the choice of the Lie algebra and the field content. A few classical solutions are constructed which correspond to Dirichlet p-branes and some fluctuations are evaluated. The particular scaling limit with matrix T duality transformation is discussed which derives the F theory compactification on an elliptic fibered K3.Comment: LaTeX, 29 pages, 3 figures. PostScript problems are fixe