Heat-resistant concrete based on alumina cement from substandard raw material

Results are provided for development of refractory concrete based on modified alumina cement using chemical industry waste. A quantitative ratio for mixed filler fractions, the effect of production factors on concrete strength, the dependence of its strength properties on form of filler, and solidification conditions are established. It is shown that with respect to physical mechanical and engineering properties the concretes developed is no worse than those existing in the market.With respect to all engineering properties this form of refractory product may be recommended as lining for high-temperature units

Heat-resistant concrete based on alumina cement from substandard raw material

Results are provided for development of refractory concrete based on modified alumina cement using chemical industry waste. A quantitative ratio for mixed filler fractions, the effect of production factors on concrete strength, the dependence of its strength properties on form of filler, and solidification conditions are established. It is shown that with respect to physical mechanical and engineering properties the concretes developed is no worse than those existing in the market.With respect to all engineering properties this form of refractory product may be recommended as lining for high-temperature units

Studying the specific features of the hydration processes of alumina cements based on the compounds of CaO–NiO–Al₂O₃ system

The article gives the results of studying hydration processes occurring in cement synthesis using waste products of chemical industry. Cement clinker was synthesized with the relation of initial raw components, calcium-containing water treatment waste and rejected nickel containing catalyst of AZOT Private Joint Stock Company (Severodonetsk, Luhansk Region, Ukraine), equal to 50/50. The obtained samples were studied by Strelkov minor method: normal density, setting time and mechanical strength were determined within 1, 3, 7 and 28 days. The results regarding the setting product were analyzed by differential thermal, X-ray phase analysis, microscopic analysis and electron microscopy; this enables to control the phase relation in the synthesis of a new class of aluminate cements using waste products of chemical industry. The obtained data showed the absence of cubic hydroaluminates which deteriorate the strength. The methods of physicochemical analysis revealed that the phase composition of hydrated alumina cement is represented by calcium hydroaluminate of different basicity, whereas cleavage structure consists of prismatic crystals which give dual coalescence, and this is favorable form to provide matrix self-reinforcement. The developed composition of aluminous nickel-containing cement referred to hydraulic binders. The results of physical-mechanical tests of the synthesized cements indicated that the obtained cements are quick-setting, fast-hardening and high-strength materials

Long-range potentials and (n−1)d+ns(n-1)d+ns molecular resonances in an ultracold rydberg gas

We have calculated long-range molecular potentials of the $0_g^{+}$, $0_u^{-}$ and $1_u$ symmetries between highly-excited rubidium atoms. Strong $np+np$ potentials characterized by these symmetries are important in describing interaction-induced phenomena in the excitation spectra of high $np$ Rydberg states. Long-range molecular resonances are such phenomena and they were first reported in S.M. Farooqi {\it et al.}, Phys. Rev. Lett. {\bf 91} 183002. One class of these resonances occurs at energies corresponding to excited atom pairs $(n-1)d+ns$. Such resonances are attributed to $\ell$-mixing due to Rydberg-Rydberg interactions so that otherwise forbidden molecular transitions become allowed. We calculate molecular potentials in Hund's case (c), use them to find the resonance lineshape and compare to experimental results.Comment: 11 pages, 7 figure

The technology of creation of the standard base for socio-economic dimensions

© Medwell Journals, 2016.Practice education standards for assessing and comparing (comparing/contrasting) heterogeneous properties of controlled processes of socio-economic spheres. Design technique and technology to create a reference framework for processes in socio-economic sphere and on this basis to apply for measuring operations scientific methods of metrology. In this researchers methods of imitating and semantic modeling in a complex with methods of the economical and statistical analysis are used. Possibility of creation of the expert system reproducing technical and operational properties of natural market metrology, formation of general estimated function and a comparable measure of productivity for a set of diverse and multidirectional indicators is discussed. The model of creation of reference base for private indicators providing an integrated rating assessment of a condition of various organizational structures and processes is developed. The conclusion is that in terms of multidirectional indicators the most viable scheme of management of organizational systems is the formation of the reference base, the formation of normative-evaluative, the synthesis of multidimensional processes to one-dimensionality of a single criterion

Analysis of phagoand antibiotic sensitivity of Enterobacteriaceae bacteria isolated from women of reproductive age

Pelvic inflammatory diseases occupy a special place in the structure of general morbidity, and are polymicrobial in nature with dominance of opportunistic microorganisms, in particular bacteria of the family Enterobacteriaceae. The aim was to study the composition of the vaginal microbiota in women of reproductive age with pelvic inflammatory diseases, as well as to determine the sensitivity of isolated microorganisms to antibiotics and bacteriophages. The study included 70 women of reproductive age, among them 37 were diagnosed with colpitis and cervicitis, 33 women in the comparison group (women screened for a diagnosis). Isolated microorganisms were identified by abdominoperineal methods, including the disk diffusion method to determine the sensitivity of microorganism cultures of Enterobacteriaceae family to antibiotics, and the method of crosses (evaluation of lytic activity of bacteriophages by the number of crosses) to determine the sensitivity to specific therapeutic bacteriophages. Vaginal biocenosis was characterized by deficit of lactobacilli (< 106 CFU/ml in 100 %), the presence of conditionally pathogenic microflora: bacteria of Enterobacteriaceae family, coccal flora and Candida fungi. From 60.0 to 89.3 % of Enterobacteria strains were resistant to aminoglycosides and quinolones, but also had a low level of sensitivity to therapeutic bacteriophages. The obtained data indicate the reduction of colonization resistance of vaginal mucosa in pelvic inflammatory diseases and specify the need to use medicinal drugs only under medical supervision to prevent clinically significant drug resistance

Measurement of the electric dipole moments for transitions to rubidium Rydberg states via Autler-Townes splitting

We present the direct measurements of electric-dipole moments for $5P_{3/2}\to nD_{5/2}$ transitions with $20<n<48$ for Rubidium atoms. The measurements were performed in an ultracold sample via observation of the Autler-Townes splitting in a three-level ladder scheme, commonly used for 2-photon excitation of Rydberg states. To the best of our knowledge, this is the first systematic measurement of the electric dipole moments for transitions from low excited states of rubidium to Rydberg states. Due to its simplicity and versatility, this method can be easily extended to other transitions and other atomic species with little constraints. Good agreement of the experimental results with theory proves the reliability of the measurement method.Comment: 12 pages, 6 figures; figure 6 replaced with correct versio

REGIONAL FEATURES OF BIFIDOBACTERIA ANTAGONISTIC ACTIVITY IN INTESTINAL MICROBIOTA OF CHILDREN LIVING IN SIBERIA

Antagonistic properties of bifidobacteria to opportunistic microorganisms in vitro and mechanism of antagonistic activity decreasing were studied and. analyzed. Great percentage of bifidobacteria regional population strains with low antagonistic activity to transitional opportunistic microorganisms is registered. It results to colonization. resistance decreasing and. requires development of the preventive probiotics therapy methods to correct

Assessment of the relationship between the vaginal microecosystem in teenage girls with reproductive disorders

Background. Violations of indigenous microflora composition associates with a wide variety of gynecological complications. Thus, the qualitative and quantitative composition of lactobacilli and their associative capacity and functional activity may serve as a criterion of microecological well-being in the body. Aim. To study species diversity of lactobacilli in vaginal biotope teenage girls with gynecological pathologies and to assess the extent of their relationship with the combination of diversity profiles associated opportunistic pathogens. Materials and methods. The study included 107 adolescents with reproductive system disorders. The study was conducted with the use of gynecological and general microbiological methods. Results. It was revealed that in vaginal biocenosis of the studied group of teenage girls dominating lactobacilli were Lactobacillus plantarum and L. crispatus, the incidence of other species did not exceed 21 %. Among the representatives of opportunistic pathogenic microflora dominated coccal microflora and Corynebacterium spp., being the part of normal flora of vaginal mucosa. Analysis of species composition revealed a statistically significant relationship between certain types of lactobacilli and opportunistic microorganisms, i.e. lactobacilli showed no antagonistic activity towards the opportunistic microorganisms, and formed symbiotic relationships with them. Conclusions. Most commonness was found among the minor species of lactobacilli (L. iners, L. gasseri, L. jensenii), coagulase-negative staphylococci and fungi of Candida genus, and that increases the risk of transformation of normal microflora in the pathological one

VAGINAL MICROECOLOGY IN WOMEN WITH THE NON-SPECIFIC GENITAL INFLAMMATORY DISEASES AND REPRODUCTIVE FUNCTION DISORDERS

We conducted the microbiological examination of vaginal microbiota in 324 women with non-specific inflammatory diseases of the genital tract and with reproductive dysfunction. According the condition of microecological balance of indigenous microflora (lactobacilli concentration) of women we have identified three types of vaginal microbiota: "normocenosis", " dysbiosis", "deep dysbiosis" We marked deficiency oflactobacilli in every fourth women (28%) with infertility and miscarriage, and deep deficit in every second (53% in the third group) - sharp depression of the indigenous microbiota and its replacement by opportunistic (facultative anaerobic and obligate anaerobic), what indicates microecological trouble in the vaginal biotope and can be one of the causes of infectious and inflammatory diseases of genitals and other reproductive disorders. It was shown that the dominant microorganisms of pathogenic microbiota (UPM) of inflammatory diseases in women are coagulase-negative staphylococci (CNS), fungi of genus Candida, Escherihia coli and Enterococcus spp. During the analysis of UPM representatives material of groups with "normocenosis", "dysbiosis" and "deep dysbiosis" an important microecological indicator was calculated which characterizing microbiocaenosis as a whole - index of species richness (ISR) - the average number of species in the composition