348 research outputs found

    Justification of binder material selection for carbon particles incorporation into fibrous electromagnetic radiation absorber

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    The paper presents justification of a binder material for incorporating carbon particles into the interfiber space of electromagnetic radiation absorber. A method for carbon particles incorporation into a fibrous material has been developed. It is based on applying a carbon-containing nanocomposite to the fibrous material’s surface. Previously, the research of carbon particles incorporation into a synthetic material by using an aqueous solution were carried out, which ensured a uniform distribution of carbon particles in the material structure. However, the properties of the material have changed significantly upon mechanical deformation. Therefore, the carbon particles incorporation process was investigated using various nanocomposites obtained on the basis of mixtures of vinyl acetate polymer, or epoxy polymer, or surface-active substance with carbon black. Based on the results of electron microscopic analysis and the reflection and transmission coefficients frequency dependences in the frequency range 0.7–17 GHz, the efficiency of using a nanocomposite based on a mixture of surface-active substance and carbon black to create electromagnetic radiation absorbers was justified. Such electromagnetic radiation absorbers have the transmission coefficient value about –18 dB and reflection coefficient value about –12 dB in the frequency range 7–13 GHz. Carbon-containing electromagnetic radiation absorbers based on fibrous material have thickness less than 3 mm, properties of flexibility and resistance to mechanical deformation. It can be used in various fields, in particular for hiding objects from radio frequency reconnaissance or protecting equipment from external interference.The paper presents justification of a binder material for incorporating carbon particles into the interfiber space of electromagnetic radiation absorber. A method for carbon particles incorporation into a fibrous material has been developed. It is based on applying a carbon-containing nanocomposite to the fibrous material’s surface. Previously, the research of carbon particles incorporation into a synthetic material by using an aqueous solution were carried out, which ensured a uniform distribution of carbon particles in the material structure. However, the properties of the material have changed significantly upon mechanical deformation. Therefore, the carbon particles incorporation process was investigated using various nanocomposites obtained on the basis of mixtures of vinyl acetate polymer, or epoxy polymer, or surface-active substance with carbon black. Based on the results of electron microscopic analysis and the reflection and transmission coefficients frequency dependences in the frequency range 0.7–17 GHz, the efficiency of using a nanocomposite based on a mixture of surface-active substance and carbon black to create electromagnetic radiation absorbers was justified. Such electromagnetic radiation absorbers have the transmission coefficient value about –18 dB and reflection coefficient value about –12 dB in the frequency range 7–13 GHz. Carbon-containing electromagnetic radiation absorbers based on fibrous material have thickness less than 3 mm, properties of flexibility and resistance to mechanical deformation. It can be used in various fields, in particular for hiding objects from radio frequency reconnaissance or protecting equipment from external interference

    Effect of Statins (Zocor) on Oxygen-Dependent Processes in Muscle Tissue and Erythrocytes in Animals with Hypercholesterolemia

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    Background. Statin therapy may be accompanied by a toxic effect on skeletal muscle and liver cells, the molecular mechanisms of which have not yet been fully understood.Aim. To clarify the peculiarities of changes in the oxygen transport function of erythrocytes and antioxidant mechanisms in erythrocytes and muscles of animals with prolonged administration of statins (simvastatin).Materials and methods. The study was conducted on outbred male rats, which during the experiment were randomlyΒ  assigned to following groups: the control group contained animals on a common ration of the vivarium, the group of comparison – animals with induced hypercholesterolemia, the main group – animals with induced hypercholesterolemia treated with simvastatin. In erythrocytes and muscle tissue of animals, indicators characterizing the state of antioxidant defense and carbohydrate metabolism were determined.The results. The experiment showed that the administration of simvastatin to animals was characterized by aggravation of hypoxia due to hypercholesterolemia, as indicated by a sharp increase in the concentration of 2,3-BPG and lactate in erythrocytes of animals, as well as a significant decrease in the activity of G6PD. In the muscle tissue of animals, there was a decrease in the Β concentration of pyruvic acid and lactate relative to the comparison group, which indicates their intensive participation in metabolic processes.Conclusion. Based on the data obtained, it can be assumed that the peculiarity of the action of statins in erythrocytesΒ  is the increased oxygen delivery to the tissues, which in muscles was accompanied by a decrease in the level of oxidized products. At the same time, against the background of the use of statins, despite the positive direction of adaptive reactions, signs of oxidative stress remain, which is documented by the imbalance of the SOD-catalase system and a decrease in the activity of glutathione-dependent reaction

    Structural features of Ni-Cr-Si-B materials obtained by different technologies

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    This study considers the structural features of Ni-Cr-Si-B (Ni - base; 15.1 % Cr; 2 % Si; 2 % B; 0.4 % C) materials obtained by different methods. The self-fluxing coatings were deposited by plasma spraying on the tubes from low carbon steel. Bulk cylinder specimens of 20 mm diameter and 15 mm height were obtained by spark plasma sintering (SPS). The structure and phase composition of these materials were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The major phases of coatings and sintered materials are [gamma]-Ni, Ni[3]B, CrB and Cr[7]C[3]. We demonstrate that the particle unmelted in the process of plasma spraying or SPS consist of [gamma]-Ni-NEB eutectic and also CrB and Cr[7]C[3] inclusions. The prolonged exposure of powder to high temperatures as well as slow cooling rates by SPS provide for the growth of the structural components as compared to those of plasma coatings materials. High cooling rates at the plasma spraying by melted particles contribute to the formation of supersaturated solid solution of Cr, Si and Fe in [gamma]-Ni. The structure of the melted particles in sintering material has gradient composition: the core constituted of Ni grains of 10 ΞΌm with [gamma]-Ni-Ni[3]B eutectic on the edges. The results of the experiment demonstrate that the sintering material has a smaller microhardness in comparison with plasma coatings (650 and 850 MPa, respectively), but at the same time the material has higher density (porosity less than 1 %) than plasma coatings (porosity about 2.. .3 %)

    Society and the state in the pandemic context

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    Based on the importance of an unprecedented new reality, the authors were tasked with studying and analyzing the problems of interaction between the State and society in the context of the pandemic and the introduction of state measures to prevent the spread of viral infection, which to a degree or another limit the rights and freedoms of a person and citize

    Current status of the temperature and humidity regime of the troposphere in the Siberian sector in different circulation periods

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    The paper studies the long-term dynamics of air temperature and relative humidity anomaly indices in the surface layer and at different levels of the troposphere in Siberia and neighboring regions (European and Far Eastern sectors). As the main cause of the observed variations in climatic parameters we considered circulation factors, which were taken into account using the typification of macrocirculation processes proposed by B.L. Dzerdzeevsky. Seasonal differences were revealed in the distribution of anomaly indices and the area occupied by anomalies of different signs of annual and monthly mean temperature and relative air humidity, which are most pronounced during circulation periods of increased duration of meridional northern processes in the Siberian sector and in the Northern Hemisphere as a whole. The highest rates of change in the temperature regime in the Siberian sector over recent decades have been observed at the level of the isobaric surface AT–700 hPa (3 km), which affects the advective-dynamic factors of surface cyclo- and frontogenesis, as well as the processes of cloud formation and precipitation. In general, an increase in the heat content of the lower and middle troposphere and a decrease in the relative moisture content near the tropopause can be accompanied by an increase in the amount of the potential energy and convective instability energy reserves and can lead to an increase in climate risks in the Siberian sector

    Terminology pediatrics

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    The article analyzes the modern terminology of Pediatrics. We have identified thematic groups and specific Latin names specific to Pediatrics. We have analyzed the Latin names; defined their structure, defined the variety of terms. We also conducted an etymological and contrastive analysis with Russian Federationn terms, noted their similarity and difference. Special attention is paid to specific Russian Federationn names, which are firmly entrenched in the language of medicine.Π’ ΡΡ‚Π°Ρ‚ΡŒΠ΅ анализируСтся соврСмСнная тСрминология ΠΏΠ΅Π΄ΠΈΠ°Ρ‚Ρ€ΠΈΠΈ. Нами Π±Ρ‹Π»ΠΈ выявлСны тСматичСскиС Π³Ρ€ΡƒΠΏΠΏΡ‹ ΠΈ спСцифичСскиС латинскиС названия, Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€Π½Ρ‹Π΅ для ΠΏΠ΅Π΄ΠΈΠ°Ρ‚Ρ€ΠΈΠΈ. Нами Π±Ρ‹Π» ΠΏΡ€ΠΎΠ²Π΅Π΄Π΅Π½ Π°Π½Π°Π»ΠΈΠ· латинских Π½Π°Π·Π²Π°Π½ΠΈΠΉ; ΠΎΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½Π° ΠΈΡ… структура, ΠΎΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½Ρ‹ разновидности Ρ‚Π΅Ρ€ΠΌΠΈΠ½ΠΎΠ². ΠœΡ‹ Ρ‚Π°ΠΊΠΆΠ΅ ΠΏΡ€ΠΎΠ²Π΅Π»ΠΈ этимологичСский ΠΈ контрастивный Π°Π½Π°Π»ΠΈΠ· с русскими Ρ‚Π΅Ρ€ΠΌΠΈΠ½Π°ΠΌΠΈ, ΠΎΡ‚ΠΌΠ΅Ρ‚ΠΈΠ»ΠΈ ΠΈΡ… ΡΡ…ΠΎΠΆΠ΅ΡΡ‚ΡŒ ΠΈ Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΠ΅. ОсобоС Π²Π½ΠΈΠΌΠ°Π½ΠΈΠ΅ удСляСтся спСцифичСским русским названиям, ΠΊΠΎΡ‚ΠΎΡ€Ρ‹Π΅ ΠΏΡ€ΠΎΡ‡Π½ΠΎ Π·Π°ΠΊΡ€Π΅ΠΏΠΈΠ»ΠΈΡΡŒ Π² языкС ΠΌΠ΅Π΄ΠΈΡ†ΠΈΠ½Ρ‹

    EFFECT OF FERROTHERAPY ON COURSE OF ISCHEMIC HEART DISEASE ASSOCIATED WITH MILD IRON DEFICIENCY IN MEN

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    Aim. To assess effect of ferrotherapy on course of ischemic heart disease (IHD) associated with mild iron deficiency anemia (IDA) and latent iron deficiency (ID). Material and methods. 80 male patients, coal miners, aged 51Β±7.9 years, were observed. 28 patients had angina pectoris associated with the mild IDA, 23 patients experienced myocardial infarction accompanied by the mild IDA and 29 patients had angina with latent ID. Latent ID was defined in case of iron plasma level ≀12 Β΅g/l, IDA was diagnosed in case of hemoglobin level <130 mg/l. The minimal hemoglobin level observed in patients was 107g/l. ICD clinical characteristics were compared before and after 3-week iron-based treatment in individualized doses. Results. Latent ID and mild IDA aggravated angina and increased ectopic myocardial activity in patients with IHD. Iron-based therapy with appropriate nutrition reduced angina attacks frequency, duration and intensity, decreased nitroglycerin consumption and increased exercise tolerance. Conclusion. Normalization of haemoglobin level and iron plasma concentration in the mild IDA as well as normalization of iron plasma concentration in ID in patients with IHD reduces ede-ma and dyspnea, decreases heart rate. These effects are provided due to the treatment with elementary iron in individualized course dose, which improves clinical status and minimizes the adverse reactions

    Patient's relationship with medical staff: ethical, normative and communicative aspects

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    The aim of the study - to research the problem of interpreting the term β€œmedical mistake” by a bioethical and legal point of viewЦСль исслСдования – ΠΏΠΎΠΊΠ°Π·Π°Ρ‚ΡŒ Π½Π΅ΠΎΠ±Ρ…ΠΎΠ΄ΠΈΠΌΠΎΡΡ‚ΡŒ соблюдСния ΠΏΡ€Π°Π²ΠΈΠ» ΠΈ Π½ΠΎΡ€ΠΌ общСния Π½Π΅ Ρ‚ΠΎΠ»ΡŒΠΊΠΎ мСдицинским Ρ€Π°Π±ΠΎΡ‚Π½ΠΈΠΊΠΎΠΌ, Π½ΠΎ ΠΈ ΠΏΠ°Ρ†ΠΈΠ΅Π½Ρ‚Π°ΠΌΠΈ
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