Electron-based crystalline undulator

We discuss the features of a crystalline undulator of the novel type based on the effect of a planar channeling of ultra-relativistic electrons in a periodically bent crystals. It is demonstrated that an electron-based undulator is feasible in the tens of GeV range of the beam energies, which is noticeably higher than the energy interval allowed in a positron-based undulator. Numerical analysis of the main parameters of the undulator as well as the characteristics of the emitted undulator radiation is carried out for 20 and 50 GeV electrons channeling in diamond and silicon crystals along the (111) crystallographic planes.Comment: 16 pages, 8 figures, Latex, IOP styl

Angular distribution of positrons in coherent pair production in deformed crystals

We investigate the angular distribution of positrons in the coherent process electronpositron pair creation process by high-energy photons in a periodically deformed single crystal with a complex base. The formula for the corresponding differential cross-section is derived for an arbitrary deformation field. The case is considered in detail when the photon enters into the crystal at small angles with respect to a crystallographic axis. The results of the numerical calculations are presented for${\mathrm{SiO}}_{2}$ and diamond single crystals and Moliere parameterization of the screened atomic potentials in the case of the deformation field generated by the acoustic wave of S-type.Comment: 11 pages, 4 figures, figures and references adde

Some Aspects of Harmonisation of Ukraine’s Competition Legislation to EU Standards

In modern conditions, obtaining information about market dynamics, trends in demand, and alternative offers from competitors is vital to support the effective operation of enterprises. It is also common business practice to discuss legislative initiatives, non-confidential technical information, quality and safety standards, and various aspects of the industry. However, the direct or indirect exchange of information may be accompanied by various wrongful intentions of economic entities (for example, elimination of competitors, creation of entry barriers, agreement on price levels, certain discounts, sales volumes, and the market's geographical distribution, etc.). In Ukraine, there are currently no analogues of a full-fledged guide to information exchange between competitors, which determined the relevance of this study. The purpose of the study is to establish regulatory, economic principles for assessing the exchange of information between enterprises operating in the relevant market, in the context of compliance with legislation on protection of economic competition; analysis of the progressive international practice of cessation of violations in the form of information exchange, which leads to distortion of economic competition. In Ukraine, it is necessary to adopt the Guidelines for the Exchange of Information between Competitors (from now on referred to as "the Guidelines"), raising awareness of the business community (including associations and chambers of commerce), lawyers, and society in general regarding the main aspects of the competition compliance with competition law in order to promote fair business activities, protect the competitive environment and, as a consequence, improve consumer welfare. Keywords: Antimonopoly Committee of Ukraine, anti-competitive consequences, competition legislation, oligopolistic market, conspiracy

Stable propagation of a modulated positron beam in a bent crystal channel

The propagation of a modulated positron beam in a planar crystal channel is investigated. It is demonstrated that the beam preserves its modulation at sufficiently large penetration depths which opens the prospect of using a crystalline undulator as a coherent source of hard x-rays. This finding is a crucial milestone in developing a new type of lasers radiating in the hard x-ray and gamma-ray range.Comment: 11 pages, 4 figures, iopar

The myogymnastics complex as an element of rehabilitation in the process of adaptation to orthopedic appliances in patients after stroke

Introduction. Stroke has become the second leading cause of long-term disability and cognitive impairment. The disease can cause debilitating neurological disorders that lead to motor, sensory and cognitive deficits and impaired psychosocial functioning. Many researchers have established an association between dental status, infections, and systemic diseases such as acute cerebrovascular disorder.The aim of the research was to determine the impact of dental health on the quality of life in patients with cerebral circulatory disorders complicated with neurological deficits by hemitype before and 30 days after orthopedic treatment by questionnaire survey.Materials and methods. The study involved 25 people with the course of ACVD complicated with neurological deficiency by hemitype, aged from 40 to 65 years, who underwent prosthetics with partial removable laminar dentures with acrylic base and retaining bent, metal clasps according to clinical indications. The first group, where the process of adaptation to the orthopedic appliance was normal, consisted of 13 people, including 7 women and 6 men. In the second group, the adaptation process took place using the proposed rehabilitation complex, and it comprised 12 patients, including 7 women and 5 men.The changes that occurred 30 days after applying a partial removable laminar denture were as follows:The value of the indicator of restricted masticatory function in subjects of the first study group was worse by 1.375 points as compared to the second group. The value of the indicator of physical pain in the process of adaptation to the orthopedic appliance was noteworthy, since it decreased significantly in the second group and amounted to 14.404 points, which was by 1.335 points higher than in patients of the first group.The level of psychological discomfort in patients of the first group was 32.412 points, which was 1.183 points different from that of patients in the second group, in favor of the latter. At the same time, a comparison of the level of psychological inferiority showed that this indicator was higher in the first group than in the second study group by 0.988 points, i.e., the dynamics of changes in this indicator was better in the second one.Comparison of the level of social inferiority showed that in the first study group it was higher by 2.106 points than in the third group. Comparison of the level of disability showed a difference of this indicator by 1.226 points in favor of patients of the second groupThe above data suggest a general trend of improving the basic health indicators of patients in the process of orthopedic rehabilitation. At the same time, there was a clear difference between the results of the questionnaire survey between patients of the first and second groups, and these indicators were better in the latter.Conclusions. The effectiveness of the proposed rehabilitation complex for patients with cerebral circulatory disorders complicated with neurological deficiency by hemitype after prosthetics with partial removable laminar appliances was confirmed by a decrease in numerical data from the questionnaire survey by 15%, indicating an improvement in quality of life in this category of patients