Simulating Thermal Sheet Cutting of Figured Parts

This paper considers the problem of modelling the thermal cutting process of sheet material, which occurs when cutting using equipment, such as laser, gas, etc. The aim of the study is to solve the problem of optimizing the toolpath while considering the thermal effects that occur in the material being cut. A problem statement is given in this paper. An approach to modelling the change in temperature of the material during cutting is proposed, based on a discrete representation of information. The results of the computational experiment are also given. © 2022 The Authors. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)Ministry of Science and Higher Education of the Russian Federation, (FEUZ -2020-0020)This work was financially supported by Ministry of Science and Higher Education of Russia FEUZ -2020-0020

The 3D Object Packing Problem into a Parallelepiped Container Based on Discrete-Logical Representation

The problem of 3D geometric objects irregular tight packing into minimal height cuboid is considered. Main approaches to solving this problem are described. The no-fit-polyhedron based algorithm using discrete-logical representation is proposed. Some examples and computational results are also given for public input data. © 2016The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.000

Antibiotic resistance of microbial community of the lake Baikal ecosystem in the area of Listvyanka, Slyudyanka and Baikalsk

The article presents the results of study of antibiotic resistance of bacteria isolated from the lake Baikal ecosystem. It was revealed that in the littoral zone of the lake Baikal (area of Listvyanka, Baikalsk, Slyudyanka) under the anthropogenic impact there are strains of microorganisms resistant to a wide range of antibiotics. Strains resistant to all antibiotics are 1 % of the isolated bacterial strains; strains sensitive to all antibiotics are 6 %; strains isolated from the drill samples of bottom sediments are 80 %. This phenomenon can be considered as an indicator of anthropogenic influence

Cardiac tumors: analysis of surgical treatment

Aim. To analyze the preoperative status, intraoperative tumor characteristics and further clinical manifestations in patients after surgery for a cardiac tumor.Material and methods. The study included 54 patients who were operated on for a heart tumor from 2014 to 2020. We assessed clinical performance, diagnostic investigations before and after (during hospitalization) surgery, tumor size and histological characteristics.Results. Among patients operated on for cardiac tumors, women predominated (74%). Among comorbidities, hypertension (79,3%), chronic kidney disease (48,3%), and obesity (25,9%) were most common. There were following clinical manifestations before surgery: shortness of breath — 47 (81%) patients, palpitations and heart rhythm disturbance — 26 (44,8%), chest pain — 25 (43,1%), chest discomfort — 28 (49,1%), edema — 6 patients (10,3%). The predominant tumor localization was the left atrial fossa ovalis area (50%). According to histological analysis, myxoma prevailed — 38 cases (86,4%). After surgery, atrial fibrillation prevalence decreased from 8 patients before surgery to 6 after surgery (p=0,034), while left atrial size decreased by 0,6 mm (95% confidence interval, 4,39-6,2 mm) (p<0,001).Conclusion. According to presented analysis over a 6-year period, cardiac neoplasms are more common in women (74,1%), while the mean age of patients is 59,7 years. Among comorbidities, hypertension prevails — 79,3%. Histological examination revealed a predominance of myxoma (86,4%). Predominant tumor location was the left atrial fossa ovalis area (50%). Surgical treatment of neoplasms was effective. So, prevalence of atrial fibrillation decreased by 25%, while left atrial size decreased by 0,6 mm. Postoperative complications and in-hospital deaths were not registered

Physiological responses to water deficiency in bread wheat (Triticum aestivum L.) lines with genetically different leaf pubescence

Studying the relationship between leaf pubescence and drought resistance is important for assessing Triticum aestivum L. genetic resources. The aim of the work was to assess resistance of common wheat genotypes with different composition and allelic state of genes that determine the leaf pubescence phenotype. We compared the drought resistance wheat variety Saratovskaya 29 (S29) with densely pubescent leaves, carrying the dominant alleles of the Hl1 and Hl3 genes, and two near isogenic lines, i: S29 hl1, hl3 and i: S29 Hl2aesp, with the introgression of the additional pubescence gene from diploid species Aegilops speltoides. Under controlled conditions of the climatic chamber, the photosynthetic pigments content, the activity of ascorbate-glutathione cycle enzymes and also the parameters of chlorophyll fluorescence used to assess the physiological state of the plants photosynthetic apparatus were studied in the leaves of S29 and the lines. Tolerance was evaluated using the comprehensive index D, calculated on the basis of the studied physiological characteristics. The recessive state of pubescence genes, as well as the introduction of the additional Hl2aesp gene, led to a 6-fold decrease in D. Under the water deficit influence, the fluorescence parameters profile changed in the lines, and the viability index decreased compared with S29. Under drought, the activity of ascorbate peroxidase, glutathione reductase and dehydroascorbate reductase in the line i: S29 hl1, hl3 decreased 1.9, 3.3 and 2.3 times, in the line i: S29 Hl2aesp it decreased 1.8, 3.6 and 1.8 times respectively, compared with S29. In a hydroponic greenhouse, line productivity was studied. Compared with S29, the thousand grains mass in the line i: S29 hl1, hl3 under water deficit was reduced. The productivity of the line i: S29 Hl2aesp was significantly reduced regardless of water supply conditions in comparison with S29. Presumably, the revealed effects are associated with violations of cross-regulatory interactions between the proteins of the trichome formation network and transcription factors that regulate plant growth and stress response