25 research outputs found

    Innovative ways to control dust and explosion safety of mine workings

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    Ensuring dust and explosion safety during underground coal mining is one of the most important tasks of industrial safety and labor protection departments. The main method of preventing explosions of coal dust settled in mine workings is to process them with stone dust (rock dusting). The traditional methods of quality control of rock dusting include radioisotope, optical and chemical methods. To implement them, the devices are equipped with environmentally harmful radioactive elements, expensive optical sensors, desiccants and replaceable flasks with chemical reagents, which increases the cost of analysis and its duration. The measurement error of these devices is 10 % or more. The main purpose of the study is to develop and substantiate a new method for monitoring the dust and explosion safety of mine workings, which will be devoid of the disadvantages of the methods mentioned above. It is proposed to evaluate the quality of rock-dust distribution by a fundamentally new way – thermogravimetric. The method was tested on the dust of coal mines in Kuzbass and the Vorkuta basin, including dust samples taken in mines with actual explosions. The article presents the results of experimental studies of the processes of thermal destruction of coal and stone dust mixtures. The non-overlapping intervals of the thermogravimetric reaction are identified: moisture yield (35-132 °С); volatile matter yield from coal (380-580 °С); thermal degradation of limestone with carbon dioxide yield (650-850 °С). Methods and mathematical dependencies for processing significant and qualitative identification characteristics of thermogravimetric curves in determining the content of non-combustible components in a sample of mine dust are considered

    Bioregulation of amplitude-phase biological activity of Candida albicans by women reproductive tract microsymbionts

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    In this study, we propose a chronobiological method for examining inter-microbial interactions in bacterial and fungal associations in female reproductive tract. Fungal and bacterial species were isolated in 45 women of reproductive aged 19–35, with regular menstrual cycle, applying no hormonal contraceptives, without previous gynecological surgery, abortions, miscarriages with vaginal eubiosis and dysbiosis in history. Sexually transmitted diseases (HIV infection, syphilis, gonorrhea, trichomoniasis, chlamydiosis) were excluded in all subjects. Proliferation rate, morphogenesis and phospholipase activity were examined within the 48-hour period every 4 hours, in winter time, Moon phase IV. The data obtained were assessed by using Student’s t-test, Wilcoxon test, and least squares method. All subjects were divided into the groups: group 1 — women with vaginal eubiosis, group 2 — women with vaginal dysbiosis. It was shown that in all subjects experimental parameters of C. albicans cultures showed a diurnal dynamics characterized in healthy women by circadian rhythms with a single peak of activity. However, in women with vaginal dysbiosis C. albicans was characterized by significant ultradian (around 12 hours long) rhythms with two peaks of biological activity. Concurrence and consistency in manifested physiological functions related to clinical isolates was coupled to temporal pattern of distributed biological resources in fungi depending on course of infectious process. It was found that in vaginal eubiosis exometabolites released by dominant associated microbiota did not significantly change microbiota-related amplitude-phase parameters. The data obtained evidenced that temporal pattern of parameters related to C. albicans from healthy individuals was stable and independent on bacterial metabolites. In contrast, dominant microsymbiont in vaginal dysbiosis inhibited fungi-related rhythms, which might be important in establishing lactobacillus-associated biotope colonization resistance. Effects of metabolites released by the associated microbiota typical to dysbiosis was revealed by increased mesor, amplitude, preserved biorhythm spectral pattern in examined properties as well as amplitude-phase characteristics indicating at enhanced or sustained C. albicans adaptive potential. Therefore, the amplitude-phase parameter of C. albicans physiological activity served as a marker of opposite (enhanced/weakened) effect of microsymbiont survival described in “microbial dominant-associate” pairs

    Iron-based ultrafine particles made in mode solutions and industrial waste waters

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    Iron and attendant impurities settled from industrial waste water by ferritizing and formation of nanoparticles in batch bacterials culture have been studies. Iron settlement by ferritizing forms magnetic sediment extractable by magnetic separation..

    Generation of electromagnetic fields of extremely high intensity by coherent summation of Cherenkov superradiance pulses

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    We demonstrate both theoretically and experimentally the possibility of correlating the phase of a Cherenkov superradiance (SR) pulse to the sharp edge of a current pulse, when spontaneous emission of the electron bunch edge serves as the seed for SR processes. By division of the driving voltage pulse across several parallel channels equipped with independent cathodes we can synchronize several SR sources to arrange a two-dimensional array. In the experiments carried out, coherent summation of radiation from four independent 8-mm wavelength band SR generators with peak power 600 MW results in the interference maximum of the directional diagram with an intensity that is equivalent to radiation from a single source with a power of 10 GW

    Method of determining strength of green refractories

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