A numerical study of combustion in bidirectional swirling jets arrays is performed for the first time. A choice of bidirectional flow for designing burner arrays is caused by their advanced properties in terms of combustion stability, long fuel residence time, pollutants emission, etc. The simplest array studied in the paper is of square shape (3 × 3) and consists of the central toroidal bidirectional chamber and 8 peripheral cylindrical chambers. Such a decision is made to improve the stability of combustion due to the advantages of the toroidal shape known from the previous studies. The main result for the square array is that the flame surface area increases significantly, and the fuel burning rate is 1.68 times more compared to a single bidirectional chamber. Additionally, the simulations show that the key factor in array combustion stability is related to the formation of central recirculation zones in each bidirectional jet. Based on these results, the multipoint gas turbine combustor is designed. Its primary combustion zone is formed using the multiplied 3 × 3 array of bidirectional jets over the annulus. Thus, the overall number of simple vortex chambers in the annular array is 90. A numerical simulation of the new multipoint combustor operation shows a very intense jets interaction in its first half and its efficiency is more than 99%. Moreover, the calculated emission properties at an overall pressure ratio OPR = 40 suit the modern environmental requirements: CO = 12 ppm, NO = 22 ppm.

Ant-decapitating flies (lat. Megaselia scalaris (Loew)) is a quarantine object in the Russian Federation and is included in the Single list of quarantine objects of the Eurasian Economic Union, approved by the of the Council of the Eurasian Economic Commission dated 30.11.2016 No. 158, because it is a vector of dangerous diseases that cause great economic damage. The range covers large areas of North America, Africa, southern Europe, Australia, Southeast Asia, as well as the European part of Russia, namely the Southern Federal District and the Republic of Crimea. The list of regulated products subject to research to identify M. scalaris (Loew) is very extensive, and accurate identification to species of the received samples by entomological method by morphological features of copulatory organs is very labor-intensive and not accurate. Therefore, methods of molecular diagnostics were developed for identification, namely, comparison of the studied nucleotide sequence with the reference one using NCBI database and determination of genetic distances. The studies were carried out on the basis of the Department of Molecular Research of the North-West Testing Laboratory of FGBU «ARRIAH». Six samples of the genus Megaselia were used in this work. At the first stage, DNA was isolated using DNA-Extran 2 kits. Then genetic markers were obtained by classical PCR with subsequent detection by electrophoresis using the T100 Thermal Cycler, sequenced on a 3500 Genetic Analyzer. Identification was performed by comparing the obtained sequence in BioEdit program using NCBI database and by calculating genetic distances using two-parameter Kimura model and Tajima-Nei model. The study revealed advantages and disadvantages of the presented methods of molecular identification.

Currently, three groups of scientists are developing the introduction and use of lowfrequency ultrasound in retinal and vitreous surgery. There is not enough data and work to study the effects of this type of energy on the functional activity and structural state of the retina. In this regard, we conducted experimental and diagnostic studies using modern and objective methods. The main purpose of this article is analyzing the parameters of the electroretinogram of the rabbit retina and compare it with histological data after removal of the vitreous body using low-frequency ultrasound and mechanical action. Experiments were conducted on Chinchilla rabbits (n=40). In the experimental group (n=20), vitreous removal was performed using low-frequency ultrasound, in the control group (n=20) using a guillotine mechanism. On the 1st, 7th, 14th and 14th days, the parameters of the a- and b-waves of the electroretinogram were recorded. The structural state of the retina was also evaluated on histological sections. On the 1st day after surgery in both study groups there was a decrease in all parameters of the electroretinogram, the evaluation of histological data showed the presence of edema in most layers of the retina. On days 7 and 14, the parameters of the a- and b-waves were restored, but did not return to normal in both groups, a decrease in edema in all layers of the retina was observed on histological preparations. On day 30, the a- and b-wave indicators returned to normal, which indicates the restoration of the functional properties of photoreceptor cells, bipolar and Muller cells in both groups, the retinal layers were clearly visualized on histological sections without signs of edema. Analysis of electroretinogram parameters and histological data showed that the use of low-frequency ultrasound for vitreous removal can be considered safe and promising for further development.

Ivankovskoe reservoir, the oldest of the cascade of Volga reservoirs. Based on research materials from 1998 to 2021, a review of the dynamics of stocks and biological indicators of the main fish species of the Ivankovo reservoir has been prepared. Data on their stocks and catch by users are given, the resource capabilities of the reservoir are shown. Recommendations are given on the rational use of aquatic biological resources of the reservoir, it is proposed to resume industrial fishing and increase the catch of roach, grouper, perch, crucian carp, tench, etc. underutilized species by 20%, which will allow obtaining additional high-quality freshwater fish.

The article shows a comparative analysis which is done in order to evaluate the effectiveness of various types of local anesthesia in the treatment of maxillary posterior teeth. The technique of intraosseous anesthesia was considered in the article and the tasks that are necessary to obtain an effective anesthetic effect were identified. The list of advantages and disadvantages of this anesthesia type was mentioned. It has been established that intraosseous anesthesia is less invasive technique due to the fact that it allows to relieve the pain locally in the area of surgical treatment, without affecting the adjacent tissues, in the area of which manipulations are not carried out.