Near-Field Light-Bending Photonic Switch: Physics of Switching Based on Three-Dimensional Poynting Vector Analysis

Photonic hook is a high-intensity, bent light focus with a proportional curvature to the wavelength of the incident light. Based on this unique light-bending phenomenon, a novel near-field photonic switch by means of a right-trapezoid dielectric Janus particle-lens embedded in the core of a planar waveguide is proposed for switching the photonic signals at two common optical communication wavelengths, 1310 nm and 1550 nm, by using numerical simulations. The signals at these two wavelengths can be guided to different routes according to their oppositely bent photonic hooks to realise wavelength selective switching. The switching mechanism is analysed by an in-house developed three-dimensional (3D) Poynting vector visualisation technology. It demonstrates that the 3D distribution and number of Poynting vector vortexes produced by the particle highly affect the shapes and bending directions of the photonic hooks causing the near-field switching, and multiple independent high-magnitude areas matched by the regional Poynting vector streamlines can form these photonic hooks. The corresponding mechanism can only be represented by 3D Poynting vector distributions and is being reported for the first time

Developing of modern cultivation technology of organic potatoes

Medium term field experiment demonstrates the effectiveness of biological ways to increase potatoes yield on the sod-podzolic, light loamy soil. The effects of the following two groups of factors were studied: 1. The level of mineral nutrition provided by compost; 2. Microbiological pant protection product (bio preparations): Flavobacterin which has N fixer attribute and Vitaplan and Kartofen, which have bio fungicide features. Potatoes varieties ‘Nevsky’ and ‘Udacha’ were cultivated. The compost was applied in the dose range from 0 to 160 kg N ha-1 . Treatment with bio-preparations was carried out by potato tubers during planting and leaves during the growing season. Weeds were removed mechanically. Weather conditions had a significant impact on the formation of the crop. The average yield of standard potato tubers for 2017–2018 ranged from 14.1 to 29.3 t ha-1 . The use of both microbiological preparations and compost gave approximately the same effect and increased yields by 35–37% compared to the control. The use of compost together with bio-preparations provided an output of 27.6–29.3 t ha-1of potatoes. In 2019, the joint use of compost and biopreparations allowed to reach a yield of 40 tons ha-1 of marketable potatoes. On the basis of the obtained data, the mathematical dependences of the yield of potatoes on the dose of compost, the type of biological preparation and the complex indicator of the year conditions were determined

Exercise muscle damage: the role of ACTN3 gene polymorphism

Even the most experienced athletes are not safe from various types of muscle damage (cramp, contracture, sprain, tear and tear of the muscle). Nowadays, certain gene variations or polymorphisms associated with muscle damage caused by exercise are known. This review focuses on the polymorphism of the ACTN3 gene (Alpha-actinin-3 R577X, rs1815739), which plays an important role in the initial phase of muscle damage caused by exercises. Knowledge about how someone can respond to a specific type of exercises can help coaches individualize their athletes’ training exercises and thereby reduce the risk of injuries associated with overexertion. The purpose of this review is to provide a critical analysis of the literature on ACTN3 gene polymorphism associated with exercise-induced muscle damage both in young and old people, and the review highlights the potential mechanisms underlying these associations, which will provide a better understanding of exercise-induced muscle damage

Strategic and Tactical Tasks Development of the Arctic Zone of the Russian Federation

The article analyzes the geopolitical and military-strategic importance of the Arctic. External and internal threats to the development of this region are ascertained. The author notes the competencies of St. Petersburg in solving strategic management tasks during the socioeconomic development of the Arctic. The course of work on the substantiation of the external borders of the continental shelf of the Russian Federation in the Arctic Ocean is considered. The competencies that St. Petersburg has in developing the Arctic are substantiated