ESR dosimetry study of population in the vicinity of the Semipalatinsk Nuclear Test Site

A tooth enamel electron spin resonance (ESR) dosimetry study was carried out with the purpose of obtaining the individual absorbed radiation doses of population from settlements in the Semipalatinsk region of Kazakhstan, which was exposed to radioactive fallout traces from nuclear explosions in the Semipalatinsk Nuclear Test Site and Lop Nor test base, China. Most of the settlements are located near the central axis of radioactive fallout trace from the most contaminating surface nuclear test, which was conducted on 29 August 1949, with the maximum detected excess dose being 430 ± 93 mGy. A maximum dose of 268 ± 79 mGy was determined from the settlements located close to radioactive fallout trace resulting from surface nuclear tests on 24 August 1956 (Ust-Kamenogorsk, Znamenka, Shemonaikha, Glubokoe, Tavriya and Gagarino). An accidental dose of 56 ± 42 mGy was found in Kurchatov city residents located close to fallout trace after the nuclear test on 7 August 1962. This method was applied to human tooth enamel to obtain individual absorbed doses of residents of the Makanchi, Urdzhar and Taskesken settlements located near the Kazakhstan–Chinese border due to the influence of nuclear tests (1964–1981) at Lop Nor. The highest dose was 123 ± 32 mGy

Tooth enamel EPR dosimetry: optimization of EPR spectra recording parameters and effect of sample mass on spectral sensitivity

conditions were optimized. The uncertainty of dose determination was obtained as the mean square deviation of doses, determined with the use of a spectra deconvolution program, from the nominal doses for ten enamel samples irradiated in the range from 0 to 500 mGy. The spectra were recorded at different microwave powers and accumulation times. It was shown that minimal uncertainty is achieved at the microwave power of about 2 mW for a used spectrometer JEOL JES-FA100. It was found that a limit of the accumulation time exists beyond which uncertainty reduction is ineffective. At an established total time of measurement, reduced uncertainty is obtained by averaging the experimental doses determined from recorded spectra following intermittent sample shaking and sample tube rotation, rather than from one spectrum recorded at longer accumulation time. The effect of sample mass on the spectrometer’s sensitivity was investigated in order to find out how to make appropriate corrections

Tooth enamel EPR dosimetry: optimization of EPR spectra recording parameters and effect of sample mass on spectral sensitivity

conditions were optimized. The uncertainty of dose determination was obtained as the mean square deviation of doses, determined with the use of a spectra deconvolution program, from the nominal doses for ten enamel samples irradiated in the range from 0 to 500 mGy. The spectra were recorded at different microwave powers and accumulation times. It was shown that minimal uncertainty is achieved at the microwave power of about 2 mW for a used spectrometer JEOL JES-FA100. It was found that a limit of the accumulation time exists beyond which uncertainty reduction is ineffective. At an established total time of measurement, reduced uncertainty is obtained by averaging the experimental doses determined from recorded spectra following intermittent sample shaking and sample tube rotation, rather than from one spectrum recorded at longer accumulation time. The effect of sample mass on the spectrometer’s sensitivity was investigated in order to find out how to make appropriate corrections

Negative transformation of agricultural lands and their protection in JSC "Agricultural enterprise Kolos" of the Kochubeyevsky Municipal District of the Stavropol Territory

The article is devoted to the urgent problem of the negative transformation of fertile agricultural lands, the development of degradation processes, as well as the protection of agricultural landscapes. The results of monitoring studies show that over the past decades, the dynamics of the areas of agricultural land subject to degradation has been increasing. The intensity and accelerated development of degradation processes leads to a sharp deterioration in the quality of land and a reduction in the content of important nutrients of agricultural crops. Each degree of degradation reduces yields by 20-25%, which naturally affects the economy of agricultural production. In addition, the quality condition of agricultural landscapes needs urgent measures to protect and protect land. Each agro-climatic zone is characterized by its own special degradation processes, so for the zone of unstable humidification, where the farm under study is located, such problems are flooding, waterlogging and water erosion. The development and implementation of comprehensive security measures will stop the withdrawn negative olugenation transformation of agricultural deep land, grass preserve their tillage quality chernozem condition and ensure causes stable degree high yields of driving agricultural result crops

Assessment of the molecular cytogenetic, morphometric and biochemical parameters of Deschampsia antarctica from its southern range limit in maritime Antarctic

Different chromosomal forms of Deschampsia antarctica Desv. (Poaceae), including diploids (2n=26), hypotriploid (2n=36–38) and a genotype with an occasional occurrence of B chromosome (2n=26+0-1B) that originated from southern marginal populations (Argentine Islands region, maritime Antarctic) were studied using molecular cytogenetic, morphometric and biochemical methods. FISH analysis revealed variations in the number of rDNA sites between the diploid and hypotriploid plants. The genome size varied among plants with a different chromosome number and was on average 10.88 pg/2C for diploids and 16.46 pg/2C for hypotriploid. The mean values of leaf length of plants grown in vitro varied within a range of 5.23–9.56 cm. The total phenolic content ranged from 51.10 to 105.40 mg/g, and the total flavonoid content ranged from 1.22 to 4.67 mg/g. The amount of phenolic compounds did not differ significantly between the genotypes, while a variation in the flavonoid content was observed for L59 and DAR12. The diploids did not differ significantly among each other in terms of the number of rDNA loci, but differed slightly in their genome size. The individuals of DAR12 carrying B chromosome were similar to other diploids in terms of their genome size, but statistically differed in leaf length. The hypotriploid had both a greater number of rDNA sites and a larger genome size. No statistical correlations were observed between the genome size and leaf length or genome size and accumulation of phenolic and flavonoid compounds. The results of this study suggest that D. antarctica plants from the southern edge of the range are characterised by the heterogeneity of the studied parameters

Predictors of thromboembolic complications in patients with severe SARS-CoV-2 coronavirus infection

Aim. To identify predictors of the development of thromboembolic complications (TECs) in patients with severe SARS-CoV-2 coronavirus infection. Materials and methods. A single-center observational retrospective study included 1634 patients with a confirmed diagnosis of SARS-CoV-2 coronavirus infection. The patients were divided into 2 groups depending on the availability of the feasibility study. The criterion for inclusion of patients in the main group was the presence of venous feasibility studies in 127 patients (group I), the comparison group consisted of 1507 patients in whom the course of COVID-19 was not complicated by the development of feasibility studies (group II). Results. When performing computed tomography of the chest organs, it was revealed that patients with a feasibility study had a higher percentage of lung tissue damage than patients in the comparison group: 55% [37.5; 67.5] and 37.5% [25.0; 47.5], respectively (p0.001). The average values of C-reactive protein in I patients group were 129 [60.1; 211] ng/l, which was significantly higher than in II patients group – 41.0 [12.2; 97.6] ng/l (p0.001), interleukin-6 – 176 [52.9; 471] pg/ml and 39.4 [11.0; 107] pg/ml (p0.001), respectively. A one-factor regression analysis proved a significant contribution of comorbid pathology to the development of feasibility studies in patients with COVID-19. The presence of three nosologies at the same time: arterial hypertension, coronary heart disease (CHD) and chronic kidney disease increased the probability of a feasibility study by 4.81 times (odds ratio 4.8117, 95% confidence interval 3.2064–7.2207), in patients with arterial hypertension, CHD, chronic kidney disease and type 2 diabetes – by 5.63 times (odds ratio 5.6321, 95% confidence interval 3.1870–9.9531). Conclusion. The presence of severe comorbid pathology significantly increased the risk of developing a feasibility study in patients with COVID-19. The most significant predictors of the development of feasibility studies in patients with severe SARS-CoV-2 coronavirus infection. They are: CHD, arterial hypertension and type 2 diabetes

Cascaded Deferred Rendering

A long-standing difficulty with rendering huge distances is depth-fighting; a visual artefact produced when two or more fragments overlap either due to coplanar geometry or insufficient depth precision. This thesis presents two novel methods, Cascaded Deferred Rendering (CDR) and Logarithmic Cascaded Deferred Rendering (LogCDR), as a solution to solve depth-fighting that is due to insufficient depth precision. This thesis also evaluates an existing method, logarithmic depth buffer, comparing it against the standard depth buffer in OpenGL, CDR and LogCDR. The most prominent solution found was logarithmic depth buffer because of performance, no overhead from frustum division and extensive culling, ease of implementation and conveniences such as easier implementation of transparency.Ett långvarigt problem med att rendera stora scener är depth-fighting; en visuell artefakt som uppstår när två eller flera fragments överlappar, antingen för att det är ligger direkt på varandra eller för att det inte finns nog med precision i djupbuffern. Detta examensarbete presenterar två nya metoder, Cascaded Deferred Rendering (CDR) och Logarithmic Cascaded Deferred Rendering (LogCDR) som en lösning på depth-fighting som framträder när de inte finns nog med precision. Detta examensarbete utvärderar också en redan existerande metod, logaritmisk djupbuffer, och jämför den med standard djupbuffern i OpenGL, CDR samt LogCDR. Den mest lovande metoden funnen var logaritmisk djupbuffer för dess hastighet, lätthet att implementera och enklare att lägga till stöd för transparans till

Cascaded Deferred Rendering

A long-standing difficulty with rendering huge distances is depth-fighting; a visual artefact produced when two or more fragments overlap either due to coplanar geometry or insufficient depth precision. This thesis presents two novel methods, Cascaded Deferred Rendering (CDR) and Logarithmic Cascaded Deferred Rendering (LogCDR), as a solution to solve depth-fighting that is due to insufficient depth precision. This thesis also evaluates an existing method, logarithmic depth buffer, comparing it against the standard depth buffer in OpenGL, CDR and LogCDR. The most prominent solution found was logarithmic depth buffer because of performance, no overhead from frustum division and extensive culling, ease of implementation and conveniences such as easier implementation of transparency.Ett långvarigt problem med att rendera stora scener är depth-fighting; en visuell artefakt som uppstår när två eller flera fragments överlappar, antingen för att det är ligger direkt på varandra eller för att det inte finns nog med precision i djupbuffern. Detta examensarbete presenterar två nya metoder, Cascaded Deferred Rendering (CDR) och Logarithmic Cascaded Deferred Rendering (LogCDR) som en lösning på depth-fighting som framträder när de inte finns nog med precision. Detta examensarbete utvärderar också en redan existerande metod, logaritmisk djupbuffer, och jämför den med standard djupbuffern i OpenGL, CDR samt LogCDR. Den mest lovande metoden funnen var logaritmisk djupbuffer för dess hastighet, lätthet att implementera och enklare att lägga till stöd för transparans till

Optimization of Equipment Operation in Power Systems Based on the Use in the Design of Frequency-Dependent Models

This article is devoted to the biggest problem of our time: the development of modern and highly efficient equipment for energy systems. We propose improved mathematical models for starting asynchronous motors in isolated power systems. The results of experiments carried out on a model of an isolated network are presented. Both frequency-dependent and frequency-independent models were used. A comparison of various models is given. The advantages of the frequency-dependent model, which provides a more accurate representation of the processes, are shown. The obtained results were discussed, and the possibility of their use for future research was assessed