238 research outputs found

    Development of an Information Modeling System of Coal-Dust Fuel Injection into Tuyeres of a Blast Furnace

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    Abstract: The article considers a mathematical model of the combustion zone of a blast furnace working with the use of the injection of coal-dust fuel. In this model, two subsystems were identified: (1) subsystem of heating the particles of coal dust and volatiles released in the combustion zone; (2) subsystem of heat exchange and combustion processes in the tuyere. A two-dimensional velocity field of gas in the combustion zone was investigated. The combustion processes are considered as a set of simultaneously developing phenomena of coke burning in a layer, single pieces of coke and particles of coal dust. The model includes the following equations: total gas mass balance, gas component mass balance, gas heat balance, movement of coal dust particles, and heat balance of coal dust particles. The model calculates maximum burning temperature in the combustion zone, the distance from the cut of the tuyere to the focus of combustion, the length of the oxygen combustion zone, gas temperature, the content of gas phase components, and the degree of carbon burnout of pulverized coal at the outlet of the tuyere combustion zone. An information-modeling system has been developed. It allows for the investigation of the influence of combined blast characteristics, the properties of coke and coal-dust fuel, the geometric dimensions of tuyeres, and other factors on the temperature fields and concentrations of components of the gas phase in the combustion zone. The model also helps to select a rational mode of pulverized coal that will ensure completeness of its combustion in the tuyere combustion zone. The main functions of the program are as follows: representation of results of calculation in form of tables and diagrams, storage of options of basic data in a database, and export of results of calculation to Microsoft Excel. Conclusions were made on the reduction of the combustion temperature in the combustion zone and the approach of the focus of combustion to the tuyere when pulverized coal was injected. The authors also have established the need to use coals with certain quality characteristics and place where coal dust was introduced into the blast stream. © 2019, Allerton Press, Inc

    Epistemological models in understanding cultural and civilizational specificity

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    The article proposes a methodology for linking the formation-evolutionary, cultural-civilizational, ethnological, and cultural-anthropological models in understanding the changes of complicated sociocultural system

    Algorithm classification of municipal unions of the russian federation region based on a confidential interval estimation of tick-borne encephalitis virus incidence (transbaikalian krai as an example)

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    The algorithm of classification of municipal unions (MU is based on definition of a confidential interval of average long-term tick-borne encephalitis virus (TBE) sickness rate, as a quantitative integrated indicator of an epidemiological situation at the territory. It is proved that a decade is a sufficient period to reveal the patters that can be transferred to general totality and facilitate realization of MU classification. Distribution by MU groups is a steady characteristic of TBE morbidity at MU territories by decades in 95 % a confidential interval

    Morbidity Rates as Regards Tick-Borne Viral Encephalitis in the Russian Federation and across Federal Districts in 2009-2013. Epidemiological Situation in 2014 and Prognosis for 2015

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    . The first group comprises the greatest number of entities with year on year minimal-change morbidity. Variability of morbidity rates in the second and third groups lays premises for the major changes of TBVE long-term annual average rate across the Russian Federation

    Current State of the Issue of Hemorrhagic Fever with Renal Syndrome in the Rostov Region

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    Hemorrhagic fever with renal syndrome (HFRS) is registered in various geographical regions of the Russian Federation and occupies one of the leading positions among natural-focal human diseases in Russia. The aim of the study was to assess the epidemiological situation on HFRS in the Rostov Region. Materials and methods. Laboratory diagnostics of field material (samples from wild rodents) for the presence of antigens of HFRS pathogens and screening of blood sera from donors, residents of the region, for the presence of class G antibodies to viruses that cause HFRS were carried out by enzyme immunoassay during 2020 and 2021. Results and discussion. Hantavirus antigens were identified in five administrative districts of the Region in 2020, infection with HFRS virus in small mouse-like rodents was 7.1 %. In 2021, spontaneous infection of carriers was detected in 2.8 % of the samples, found in four districts of the Region. The presence of the virus markers was recorded in populations of five species of mouse-like rodents: house mouse, wood mouse, common vole, small wood mouse, yellow-bellied mouse. Among healthy population, class G antibodies were registered in 6.8 % in the surveyed territories in 2020, and 4.5 % in 2021. Detection of virus markers in carriers and the presence of a natural immune layer of the population as regards HFRS agents suggest the existence of a natural HFRS focus in the Rostov Region

    Assessment of the Variation Range of Agglutinability in <i>Vibrio cholerae</i> Strains Isolated in the Course of Monitoring Studies

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    The aim of the study was to retrospectively analyze the range of variability of antigenic properties and genotypic characteristics of Vibrio cholerae R-variant strains atypical in terms of agglutinability.Materials and methods. 169 strains of V. cholerae R-variant with atypical agglutinability have been studied using the “AmpliSens® Vibrio cholerae-FL” test-system. The determination of O1 antigen was carried out using the “Ig-V. cholerae О1/О139 – ELISA/dot-ELISA” reagent kit.Results and discussion. A retrospective analysis of the complex of phenoand genotypic characteristics of strains isolated from surface water bodies in the territories of three former Soviet republics and 13 constituent entities of the Russian Federation in the course of 30-year monitoring and identified upon isolation as nontoxigenic V. cholerae R-variant strains has been performed. Upon re-identification, it was found that the strains belong to both epidemically dangerous (3.0 %) and non-dangerous strains (97.0 %). The range of variability was expressed in their distribution into three groups and consisted in retaining of agglutinability only with cholera RO serum in the first group (34.5 % of strains); the loss of this trait, but the acquisition of the ability to agglutinate in different combinations with O1, Ogawa or Inaba sera – in the second (16.7 %); and also in the loss of agglutinability with all diagnostic cholera sera – in the third (48.8 %). The presence of the wbeT gene in the compared V. cholerae classical R-variant strain does not exclude the presence of the genomic region for O1 antigen biosynthesis in other R-strains, possibly in a modified form, which can be clarified in further molecular-genetic studies. Alternatively, such strains are likely to be attributed to V. cholerae nonO1/nonO139. Strains of V. cholerae R-variant with different amounts of surface antigen (optical density range – from 0.088±0.002 to 1.226±0.003) have been identified. The data obtained can be used for monitoring of cholera in laboratories of regional and federal levels

    Online service for interpretation of the resistance prediction results to bedaquiline by the molecular data

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    Background. Bedaquiline is a new and promising anti-tuberculosis drug, but longterm use requires resistance. This is due to mutations in the atpE and mmpR genes in M. tuberculosis (MBT).The aim of the research was to test a system for automated interpretation of results for predicting resistance to bedaquiline by the molecular data.Materials and methods. DNA was isolated from strains of M. tuberculosis in the Irkutsk region and Yakutia. The total quantity of DNA samples was 27 strains from Yakutia and 21 strains from the Irkutsk region. The study of MBT genomes was carried out on the DNA previously obtained by the authors in the territories of the Irkutsk region (n = 5), Yakutia (n = 4), Buryatia (n = 3), Zabaykalskiy kray (n = 4) and the Far East (n = 8). We used the BSATool program to detect bedaquiline resistance based on  Sanger and genomic data. Sanger sequencing analyzed the atpE and  mmpR genes, and whole genome sequencing examined mutations in the same sequences, as well as additionally in mmpL5, mmpS5, Rv0678, Rv1979c, and pepQ.Results. Complete agreement between the phenotypic and genotypic analysis of resistance to bedaquiline was found for three strains from Yakutia. One genome with significant mutations to bedaquiline was identified. A conclusion was made about the importance of molecular analysis of target genes with subsequent detection of resistance to bedaquiline in silico

    Применение автодинов в перспективных системах радиолокационного зондирования атмосферы

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    The results of studies of an autodyne transceiver (AT) for advanced radar sensing systems of the atmosphere are presented. A mathematical model of the APP has been developed, presented in the form of an oscillator with a single-circuit oscillatory system under the influence of a request signal from the radar. The analysis of the dynamics of signal reception in the beat mode, when the frequency of the received signal is outside the synchronization band, as well as in the capture mode, when the frequency of the request signal falls into the synchronization band of the AT. The noise and energy parameters and characteristics of the microwave generators used as an AT are investigated. Calculations of dynamic, noise and energy parameters and characteristics of the AT are performed depending on the choice of the type of conductivity characteristic of the active element and the position of the working point on it, as well as on the conditions of connection of the AT with the load. The experimental studies of the AT were carried out on the example of a serial transistor microwave module of the MRS-3MK radiosonde at a frequency of 1680 MHz. The description of the structural scheme of the AT for an aerological radiosonde operating in the beating mode is given. It is shown that the sensitivity of the AT to the request signal is determined by fluctuations in the amplitude of the microwave module and the bandwidth of the intermediate frequency amplifier. It is established that the sensitivity of the AT is minus 110...120 dB/W, for measuring the inclined range of 250...300 km is enough to have a radar transmitter with a pulse power of 50...100 W, while its average power corresponds to 0.05...0.1 W. Noskov V. Ya., Ivanov V. E., Gusev A. V., Ignatov K. A., Knyazev S. T., Kudinov S. I., Malygin I. V., Plokhikh O. V., Ponomarev O. P., Chernykh O. A. Application of autodynes in advanced systems of atmosphere radar sensing. Ural Radio Engineering Journal. 2022;6(1):11–53. (In Russ.) DOI: 10.15826/urej.2022.6.1.001. Представлены результаты исследований автодинного приемо-передатчика (АПП) для перспективных систем радиолокационного зондирования атмосферы. Разработана математическая модель АПП, представленная в виде автогенератора с одноконтурной колебательной системой, находящейся под воздействием запросного сигнала от РЛС. Выполнен анализ динамики приема сигналов в режиме биений, когда частота принимаемого сигнала находится за пределами полосы синхронизации, а также в режиме захвата, когда частота запросного сигнала попадает в полосу синхронизации АПП. Исследованы шумовые и энергетические параметры и характеристики используемых в качестве АПП СВЧ-генераторов. Выполнены расчеты динамических, шумовых и энергетических параметров и характеристик АПП в зависимости от выбора вида характеристики проводимости активного элемента и положения рабочей точки на ней, а также от условий связи АПП с нагрузкой. Экспериментальные исследования АПП выполнены на примере серийного транзисторного СВЧ-модуля радиозонда МРЗ-3МК на частоту 1680 МГц. Дано описание структурной схемы АПП для аэрологического радиозонда, работающего в режиме биений. Показано, что чувствительность АПП к запросному сигналу определяется флуктуациями амплитуды СВЧ-модуля и полосой пропускания усилителя промежуточной частоты. Установлено, что чувствительность АПП составляет минус 110...120 дБ/Вт, для измерения наклонной дальности 250...300 км достаточно иметь передатчик РЛС с импульсной мощностью 50...100 Вт, при этом средняя мощность его соответствует 0,05...0,1 Вт. Носков В. Я., Иванов В. Э., Гусев А. В., Игнатков К. А., Князев С. Т., Кудинов С. И., Малыгин И. В., Плохих О. В., Пономарев О. П., Черных О. А. Применение автодинов в перспективных системах радиолокационного зондирования атмосферы. Ural Radio Engineering Journal. 2022;6(1):11–53. DOI: 10.15826/urej.2022.6.1.001.

    Interspecific competition delays recovery of Daphnia spp. populations from pesticide stress

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    Xenobiotics alter the balance of competition between species and induce shifts in community composition. However, little is known about how these alterations affect the recovery of sensitive taxa. We exposed zooplankton communities to esfenvalerate (0.03, 0.3, and 3 μg/L) in outdoor microcosms and investigated the long-term effects on populations of Daphnia spp. To cover a broad and realistic range of environmental conditions, we established 96 microcosms with different treatments of shading and periodic harvesting. Populations of Daphnia spp. decreased in abundance for more than 8 weeks after contamination at 0.3 and 3 μg/L esfenvalerate. The period required for recovery at 0.3 and 3 μg/L was more than eight and three times longer, respectively, than the recovery period that was predicted on the basis of the life cycle of Daphnia spp. without considering the environmental context. We found that the recovery of sensitive Daphnia spp. populations depended on the initial pesticide survival and the related increase of less sensitive, competing taxa. We assert that this increase in the abundance of competing species, as well as sub-lethal effects of esfenvalerate, caused the unexpectedly prolonged effects of esfenvalerate on populations of Daphnia spp. We conclude that assessing biotic interactions is essential to understand and hence predict the effects and recovery from toxicant stress in communities

    Epizooty of Tularemia, Detected in the Population of the Common Vole in the Natural Focus of Steppe Type in the South-East of the Rostov Region in 2020

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    The aim of study was to conduct epizootiological monitoring of natural tularemia foci of the steppe type and investigate epizootic activity in the south-east of the Rostov Region.Materials and methods. An epizootiological survey was carried out on the territory of Remontnensky, Sal’sky and Peschanokopsky districts of the Rostov Region in 2019–2021. To capture and collect mammals, Ixodidae ticks and to study the samples of field material conventional methods were used.Results and discussion. Habitation of 16 species of small mammals, 6 species of Ixodidae ticks has been found. Molecular-genetic analysis of the voles has revealed the presence of the species Microtus arvalis obscurus in the studied area of the region. The circulation of the tularemia agent has been established in the population of common and social voles, forest mouse, hare, rook, Dermacentor marginatus, Hyalomma marginatum, removed from rooks. In May 2020, a high increase in the number of the social vole in the Remontnensky district (up to 21 %), in July 2020 – the common vole in the agrocenoses of the Sal’sky district (up to 33 %) was observed. An extensive epizooty of tularemia was detected in the population of common vole in the south-east of the Rostov Region and in adjacent territories in the Republic of Kalmykia and the Stavropol territory. Two cultures of the pathogen were isolated from the fallen and captured social voles, and four cultures – from the common vole. The isolated strains belong to the Holarctic subspecies of Francisella tularensis EryR. The results obtained attest to the activation of the natural tularemia focus in the south-east of the Rostov Region and its high epizootic activity
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