1,275 research outputs found

    The empirical definition of total emissivity of modern super-thin liquid composite thermal insulators

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    Modern world trends in the field of energy and mineral resources preservation policy involves the need for a more cost-efficient use of the Earth's natural resources, including in the field of construction industry. Using insulation modern materials would largely solve this problem. The acceptability appraisal of various advanced heat-insulating blankets is a crucial task, which requires experimental verification of total emissivity empirical definition of modern super-thin liquid composite thermal insulators and their real value definition. Method of investigation is as follows: an empirical definition of blankets emissivity using the proposed laboratory equipment, which comprises a system of "gray" bodies, thermocouple probe and a source of continuous heat flux. Total emissivity of modern super-thin liquid composite thermal insulators is experimentally determined. It amounted e = 0.89 for sample # 1, and e = 0.87 for sample # 2 at a temperature of 35-65 °C. It was found that the actual emissivity of the samples was higher than it had been declared

    Development of generalized requirements for automated electric drive of cable equipment

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    The article deals with the production of cable and wire products and the operation of cable processing equipment. The technological parameters of cable machines are analyzed by maintaining the range established by the regulatory documentation, and the main task of ensuring the efficiency of the technology is formulated. The requirements for automated electric drive of cable equipment are analyzed, considering the harsh modern operating conditions of cable products. The work of modern cable equipment with a high level of automation of the technological process and existing cable machines with a service life of more than 10 years is considered. The possibility of creating a unified automatic control system for both the entire technological process and a separate technological operation by creating a flexible control system for a separate cable machine with the further formation of a full-scale digital environment for the entire cable enterprise is analyzed. The developed generalized requirements for the automated electric drive of the cable machine made it possible to conduct research on specific cable equipment the VSK-13 drawing machine by creating a simulation model, and the obtained results of mathematical modeling gave good results on the computational experiment of the electromechanical system of the VSK-13 drawing machine

    DETECTION OF GENETIC DETERMINANTS OF PATHOGENICITY OF STRAINS OF KLEBSIELLA SPP. ISOLATED FROM THE INTESTINAL BIOTOPE OF CHILDREN WITH FUNCTIONAL GASTROINTESTINAL DISORDERS

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    Functional gastrointestinal disorders (FGID) are one of the most common problems in children of the first year of life. The aim of the study was to assess the pathogenic potential of Klebsiella spp. strains, isolated from the colon in children of the first year of life with FGID. Material for the study included 61 coprological samples. The biological material was divided into comparison groups, depending on the type of Klebsiella excreted at a concentration of 105–108 CFU/g: 1st – with vegetation in the colon K. pneumoniae (n = 30); 2nd – with vegetation K. oxytoca (n = 31). Bacteriological study composition of the intestinal contents was carried out according to the Industry standard “Protocol of management of patients. Intestinal dysbiosis” (2003). Identification was carried out according to generally accepted schemes using commercial test systems for biochemical identification of bacteria. Statistical data processing was performed using licensed applications “MS Office Excel 2003 for Windows 7”. The data on the quantitative and qualitative changes in the composition microbiota in the comparison groups were obtained. The results of detection genetic determinants of pathogenicity in the samples of Klebsiella of two species show that among the strains of Klebsiella spp., vegetating in the intestines of children as a component of an allochthonous microbiota, a sufficiently high and virulent potential can be concentrated. Detection of pathogenicity genes in bacteria of the genus Klebsiella will expand and deepen the problem of finding the structures of adaptation of strains of bacteria that cause FGID in children of the first year of life

    Comparison of microecological intestinal indices in children with different value of body mass index

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    The body mass index (BMI) is one of the key and at the same time simple and significant indicators of the state of the human body. Both large and small quantities of BMI is associated with high morbidity. The aim of the study was to analyze microecological disorders of intestinal biocenosis in children of different ages using the value of BMI as the criterion of comparison. We researched scatological material from 158 children and adolescents aged from 5 to 17 years (77 boys and 81 girls). The material was divided into three comparison groups depending on the BMI value: group 1 - body mass deficit (n = 34); group 2 - patients having body mass excess (n = 37); group 3 - with normal body mass (n = 87). It has been shown that more than 80 % of children with different BMI value were recorded to have dysbiotic disturbances of the intestinal microbiota of degrees 1 and 2. However, in the group of children with normal body mass, frequency of detection of intestinal dysbiosis was significantly lower; in the group of children with underweight dysbiotic disorders were found significantly more often than in overweight and obese children (p < 0.05). In children with body mass deficit we observed not only increasing concentration of opportunistic pathogenic bacteria, but also an increased occurrence of representative of Enterobacteriаceaе. family. 58.8 % of cases had two- and three-component associations of opportunistic pathogenic bacteria, which is an indication the expressed violations of the intestine microbiocenosis formation. The data obtained show that,you can use BMI, an important criterion reflecting the severity of the disease, in the assessment of intestinal microflora in combination with other studies

    Protic Ionic Liquid as Reagent, Catalyst, and Solvent: 1-Methylimidazolium Thiocyanate

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    We propose a new concept of the triple role of protic ionic liquids with nucleophilic anions: a) a regenerable solvent, b) a Brønsted acid inducing diverse transformations via general acid catalysis, and c) a source of a nucleophile. The efficiency of this strategy was demonstrated using thiocyanate-based protic ionic liquids for the ring-opening of donor-acceptor cyclopropanes. A wide variety of activated cyclopropanes were found to react with 1-methylimidazolium thiocyanate under mild metal-free conditions via unusual nitrogen attack of the ambident thiocyanate ion on the electrophilic center of the three-membered ring affording pyrrolidine-2-thiones bearing donor and acceptor substituents at the C(5) and C(3) atoms, respectively, in a single time-efficient step. The ability of 1-methylimidazolium thiocyanate to serve as a triplex reagent was exemplarily illustrated by (4+2)-annulation with 1-acyl-2-(2-hydroxyphenyl)cyclopropane, epoxide ring-opening and other organic transformations

    Microecological and associative structure of intestinal biocenosis in children with functional gastrointestinal disorders

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    The article is devoted to one of actual problems of gastroenterology - study of microbiocenosis of gastrointestinal tract in functional disorders. Functional gastrointestinal disorders (FGID) or minimal dysfunctions of digestion are frequent in the first months of child's life and provoke anxiety both in parents and in pediatricians. Aim: to explore the microbial landscape and the associative structure of the microbiota of the large intestine in children with functional disorders of the gastrointestinal tract. Subjects and methods: Intestinal microbiota composition of 225 children with functional gastrointestinal disorders and 100 healthy children was studied using bacteriological method. Results. The 88.4 % frequency of detection of intestinal eubiosis disorders is discussed. Information is provided on the species composition of the major opportunistic organisms that inhabit this biotope. According to the results, decrease of bifidobacteria amount in structure of large intestine microbiota increases rate of detection of opportunistic microorganisms - predominantly, Klebsiella genus bacteria and Staphylococcus aureus. The intestinal microbial community is dominated by multicomponent transient association. The frequency of detection of pathogenic Staphylococcus in children under one year is discussed in detail. Conclusions. A distinctive feature of the intestinal biocenosis microecological status is significantly greater spread of enterococci than in healthy children, which can be a risk for the emergence of strains with the presence of a number of pathogenecity factors that cause infectious processes

    On radiative np -> 1s + gamma transitions, induced by strong low-energy interactions,in kaonic atoms

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    We calculate the rates of the radiative transitions np -> 1s + gamma in kaonic hydrogen and kaonic deuterium, induced by strong low-energy interactions and enhanced by Coulomb interactions. The obtained results should be taken into account for the theoretical analysis of the experimental data on the X-ray spectra and yields in kaonic atoms.Comment: 10 pages, 1 figur

    Response sensitivity to bacteriophages of Staphylococcus aureus strains isolated from the microbiota of the oropharynx in children of Irkutsk

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    Dysbiotic disorders of the oropharynx takes one of the first places in the structure of morbidity worldwide. The aim of the study was to determine the peculiarities of microbiocenosis of the oropharynx in children at different ages and to assess the level of sensitivity of S. aureus strains to specific bacteriophages. Material for the study consisted of 84 smears from the oropharynx of children with inflammatory diseases of the upper respiratory tract (nasopharyngitis, pharyngitis, tonsillitis, laryngitis (J00, J02, J03, J04 according to 1CD-10). The biological material was distributed depending on the age of the surveyed: the first group - children 3-6 years (n = 61) and the second age group - children 7-12 years (n = 23). Studies of the microflora of the oropharynx were performed according to standard methods. Isolated microorganisms were identified by morphological, tinctorial, cultural and biochemical properties. The results were evaluated in accordance with the Order of USSR Ministry of Health N 535 as of April 22,1985. Specific lytic activity of bacteriophages against S. aureus was determined using preparations of staphylococcal bacteriophage and polyvalent pyobacteriophage Sexta. The sensitivity of strains of S. aureus to specific bacteriophages was assessed by the method of «crosses», according to the guidelines. Statistical analysis was performed with the use of licensed applications Offiœ Ms Excel 2007for Windows 7 BioStat v. 5.0.1.2008. Correlation analysis (Pearson method) was used. 1t has been shown that with increasing age children in the oropharynx microbial density is increasing for indicators of both normoflora (S. oralis), and of opportunistic microflora (S. β-hemolytic, S. pyogenes, S. pneumoniae, bacteria Enterobacteriaceae), especially of S. aureus (up to 74 %). Registration of sensitive strains of S. aureus in more than 70 % of cases in preschool and school-aged children is evidence of the correctness of correction of the dysbiotic disorders of the oropharynx with the use of bacteriophages of staphylococcus and Sexta
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