Development of a Method for Predicting the Recurrence of States of Atmospheric Air Pollution Concentration in Industrial Cities

This paper reports the method developed for predicting the recurrence of states related to air pollution at industrial cities based on the modified window measure. The new scientific result implies that dangerous states of the urban air pollution should be identified and predicted based not on the prediction of the concentration of pollution as it is, but based on forecasting the recurrence of states of the concentration of atmospheric air pollutions. The proposed prediction method makes it possible to operatively forecast not only the clear but also hidden dangerous states of air pollution at industrial cities. This provides for an overall improvement in the effectiveness of interventions to prevent hazardous contamination of the atmosphere and the environment. The results of experimental testing indicate the feasibility of the proposed method. It was established that in the test interval of monitoring (between counts 12‒36) there were sharp characteristic changes in the predicted measure for the recurrence of state. It is noted that such changes are the predictors of hidden events involving hazardous air pollution at industrial cities. It was experimentally found that a more accurate forecast is ensured for the forecast horizon d=1 (6 hours). It is shown that in the considered case, in order to ensure the reliability of forecasting laminar states in the contaminated atmosphere, the smoothing parameter to be selected should not be less than 0.8. It is noted that in order to predict dangerous states of the atmosphere pollution based on the dynamics in the prediction of a state recurrence measure, there is no need in the information about meteorological conditions at the time of forecasting and in the future. This is the main distinguishing feature and advantage of the proposed prediction method. A given method for RS forecasting proves to be invariant to urban configuration, the types of stationary and mobile pollution sources, as well as meteorological condition

Development of the Method for Rapid Detection of Hazardous Atmospheric Pollution of Cities with the Help of Recurrence Measures

The method for rapid detection of hazardous pollution of the atmosphere of cities, which is based on dynamic measures of recurrence (repeatability) of the states of the pollution concentration vector, was developed. The new scientific result is related to the use of the unconventional modification of the known measures of recurrence based on the dynamic window averaging the current recurrence of the states of atmospheric pollution concentration. One type of a window has the width that is increasing over actual time of measurements. The other type uses the window of a fixed width that is movable over the time of measurements. The modified measures take into consideration the integrated nature of explicit and hidden destabilizing factors that contribute to current pollution concentration at the point of control. In this case, it is emphasized that there is no need to take into consideration the traditional meteorological or other conditions when identifying hazardous pollution of the atmosphere. The developed method makes it possible to detect rapidly not only explicit, but also hidden dangerous pollutions of the air basin in cities and thus to improve the effectiveness and timeliness of the measures to reduce the harmful effects of pollution of the atmosphere on the population and the environment. Nitrogen dioxide was considered as a hazardous pollutant during the experimental verification of the method. It was established experimentally that the dynamics of the concentration of nitrogen dioxide in the atmosphere of a typical urban configuration has a fractal structure, which depends on the pollution control points. In this case, these structures are characterized by the existence of the elements of periodic and extreme topologies with sharp changes in dynamics. The modified measures were found to characterize the features of specific structures and to detect not only explicit, but also hidden hazards of atmosphere pollution. In this experiment, the dynamics of the modified measures varies from zero to 0.78 units. It was shown that the maximum value of the measures belongs to the interval of observation, which is determined by 12–36 counts. It was established that at the studied control points, current concentrations of nitrogen dioxide exceeded the limit concentrations by 2.75–4.5 times and admissible maximum single concentrations – by 1.3–2.1 times. It was determined that abrupt changes in the dynamics of the modified measures can serve as an indicator of not only explicit, but also hidden hazardous pollution of the atmosphere of citie

Development of Communication Models of Wireless Environment in Emergency Situations

Two-point communication model of the wireless environment with one-beam and multi-beam propagation of radio waves were developed. The specified models make it possible to create various particular two-point communication models of wireless environment, taking into account the assigned geometry of location of shadowing and scattering structures in the environment. The practical use of the proposed models is limited to arbitrary points of radiation and reception in the environment, taking into account location of directional aerials in them. To study known multipoint technologies under conditions of emergency situations, we developed the multipoint communication models with one-beam and multibeam propagation of radio waves from each radiation point to each reception point, predetermined by the presence of shadowing and scattering structures in the environment. The developed multipoint models make it possible to create specific models at the physical level for various multi-aerial technologies, taking into consideration the use of aerial arrays of arbitrary configuration at the transmitting and receiving sides. Verification of the developed communication models of the wireless environment was performed. It was found that the use of directional aerials at the transmitting and receiving sides of the wireless environment in the presence of considerable shadowing and scattering structures makes it possible to significantly improve noise immunity. It is noted that with the use of the developed communication models, it is possible to carry out in-depth examination of the physical level with a view to developing a reliable and stable architecture of communications under conditions of emergency situations

Analysis of Correlation Dimensionality of the State of a Gas Medium at Early Ignition of Materials

We have considered the application of the method of nonlinear dynamic systems in order to analyze and detect the structural patterns in the dynamics of increments in the state of a gas medium generated by early ignitions of materials in a non-sealed chamber. The research method is based on analysis of the correlation dimensionality of increments in the state of a gas medium during ignition of materials. We have theoretically justified the method for evaluating the dynamics of correlation dimensionality of increments in the state of a gas medium at ignition. The considered method for CD evaluation is based on the computation of the Grassberger-Procaccia correlation integral, applied to the gas medium state increments using a sliding window with a fixed width. That allowed us to derive a current estimate of CD increments in the state of the gas medium during ignition of flammable materials in a chamber synchronized with the observation data acquisition rate. We have analyzed the dynamics of correlation dimensionality of increments in the state of a gas medium at early ignition of alcohol, paper, wood, and textiles in a simulation chamber. It was established that for the investigated state of the gas medium during ignition of various examined materials, the dynamics of correlation dimensionality is within 0.1 to 0.6. It is noted that this fact testifies to the fractal structure of the considered increments in the state of a gas medium in a chamber and its chaotic dynamics at the emergence of ignition sites of tested materials. In this case, the fractal structure is not the same, suggesting a "transitional chaos" in the examined state of the gas medium. It was established that current estimates of the correlation dimensionality of increments in the state at the time of materials ignition tend to a sharp increase. A given fact can be used to reliably detect early fires indoors. The results obtained are important for the in-depth studying and understanding of patterns in the structure of dynamics of increments in the state of a gas medium at early ignition. It has been shown the increments in the states of a gas medium at premises characterize it as a chaotic dynamic system with a small fractal dimensionality as opposed to the traditional approach assuming a gas medium being either deterministic or random syste

Results of Experimental Research Into Correlations Between Hazardous Factors of Ignition of Materials in Premises

We presented results of experimental research into dynamics of hazardous factors of the state of environment, as well as of their autocorrelations and pair correlations in a simulation chamber at various lags for early detection of ignition of combustible materials, such as alcohol, paper, timber and textiles. The study was carried out based of Pearson coefficient of lag correlation that possesses the best interpretability of results. It was found that dynamics of factors of the state of environment in space of the studied factors prior to ignition of materials is locally inhomogeneous and distributed with random transitions between local states. At ignition, in the studied environment, there occurs grouping of its distributed local states depending on material of ignition. It was established that the character of grouping can be used as an indicator of early detection of ignition and identification of the type of combustible material. In this case, early ignition causes a slight increase in constant of time of fluctuations of the studied factors of environment. However, this indicator has insufficient differentiability for early detection of ignitions. A more informative indicator is a degree of mutual correlation of fluctuations of environmental factors at zero lag. It was found that for alcohol, paper, timber and textiles, an effective indicator of early detection of their ignition is coefficient of pair correlation of CO and temperature, the module of which is close to 1, and for textiles – to –

Development of the Method for Rapid Detection of Hazardous Atmospheric Pollution of Cities with the Help of Recurrence Measures

The method for rapid detection of hazardous pollution of the atmosphere of cities, which is based on dynamic measures of recurrence (repeatability) of the states of the pollution concentration vector, was developed. The new scientific result is related to the use of the unconventional modification of the known measures of recurrence based on the dynamic window averaging the current recurrence of the states of atmospheric pollution concentration. One type of a window has the width that is increasing over actual time of measurements. The other type uses the window of a fixed width that is movable over the time of measurements. The modified measures take into consideration the integrated nature of explicit and hidden destabilizing factors that contribute to current pollution concentration at the point of control. In this case, it is emphasized that there is no need to take into consideration the traditional meteorological or other conditions when identifying hazardous pollution of the atmosphere. The developed method makes it possible to detect rapidly not only explicit, but also hidden dangerous pollutions of the air basin in cities and thus to improve the effectiveness and timeliness of the measures to reduce the harmful effects of pollution of the atmosphere on the population and the environment. Nitrogen dioxide was considered as a hazardous pollutant during the experimental verification of the method. It was established experimentally that the dynamics of the concentration of nitrogen dioxide in the atmosphere of a typical urban configuration has a fractal structure, which depends on the pollution control points. In this case, these structures are characterized by the existence of the elements of periodic and extreme topologies with sharp changes in dynamics. The modified measures were found to characterize the features of specific structures and to detect not only explicit, but also hidden hazards of atmosphere pollution. In this experiment, the dynamics of the modified measures varies from zero to 0.78 units. It was shown that the maximum value of the measures belongs to the interval of observation, which is determined by 12–36 counts. It was established that at the studied control points, current concentrations of nitrogen dioxide exceeded the limit concentrations by 2.75–4.5 times and admissible maximum single concentrations – by 1.3–2.1 times. It was determined that abrupt changes in the dynamics of the modified measures can serve as an indicator of not only explicit, but also hidden hazardous pollution of the atmosphere of citie

Study of the Free Surface Energy of Epoxy Composites Using an Automated Measurement System

Results of development of the automated measurement system (AMS) for determining contact wetting angles and calculations of components of free surface energy (FSE) of solid surfaces by the Van Oss-Chaudhury-Good method were presented. It was shown that AMS allows for calculations based on experimental measurement of geometrical parameters of a lying drop on the surface and energy characteristics of test fluids. It was found that the measured contact wetting angles and calculated values of FSE components of surfaces of epoxy polymer composites, steel and glass are adequate and reliable.Based on the conducted measurements and calculations, relationship between FSE, the structure and properties of epoxy polymer composites, filled with rutile, was established. In the course of research that was conducted using AMS, it was found that at an increase of the content of rutile, total FSE (γs), dispersive (γd) and acidic-basic (γab) components of composites increase. Dependences γs and γd on the filler's content are extreme in character, and γab increases and does not change at a subsequent increase in the amount of rutile. The influence of rutile is represented most vividly by dependences of the acidic (γa) and basic (γb) components, into which the polar (acidic-basic) FSE component γab is disintegrated. It was found that structural transformations are associated with the acidic-basic mechanism of intermolecular and inter-phase interactions in epoxy composition

Use of Uncertainty Function for Identification of Hazardous States of Atmospheric Pollution Vector

The use of estimation of the values of the uncertainty function to identify hazardous states of an arbitrary atmospheric pollution vector is considered. At the same time, it is proposed to estimate the uncertainty function in a fixed-width window moving along the trajectory of the state vector. This allows not only identifying the occurrence of hazardous states of atmospheric pollution, but also determining their radial velocity relative to the monitoring post. Zero radial velocity of hazardous states of atmospheric pollution allows identifying current states of no pollution dispersion in the atmosphere. These states turn out to be especially dangerous, since they lead to the accumulation of pollution and an increase in their concentration in the atmosphere. Verification of the possibility of using the uncertainty function to identify hazardous states of the atmospheric pollution vector was carried out using experimental data. At the same time, formaldehyde, ammonia and carbon monoxide were considered as hazardous components of the state vector of atmospheric pollution. The verification results generally indicate the possibility of using the uncertainty function to identify hazardous states of the atmospheric pollution vector. The use of uncertainty function is found to be invariant with respect to the irregularity of recording of atmospheric pollution at stationary monitoring posts. It is shown that the use of uncertainty function enables the identification of hazardous states characterized not only by exceeding the maximum permissible concentrations, but also by the zero radial velocity relative to the monitoring point. It is experimentally found that in order to identify hazardous states of atmospheric pollution, the window length should be from 4 to 8 reading

Research of the Intramolecular Interactions and Structure in Epoxyamine Composites with Dispersed Oxides

With the help of the software package HyprChem, using a method of quantum-chemical modeling, research into intermolecular interactions between epoxyamine grid and oxides of different chemical nature Al2O3, Fe2O3, TiO2, СаО was carried out. To take into account hydroxyl-hydrate surface layer of oxides, molecular complexes of the fragment of epoxyamine grid and hydroxides of metals Al(OH)3, Fe(OH)3, Ti(OH)4, Ca(OH)2 were used as models. As a result of modeling, it was established that Ca(OH)2 molecule forms strong intermolecular bonds and has the greatest influence on the spatial conformation of the epoxyamine fragment. It was shown that a calcium atom is oriented to π-electron cloud of the benzene ring with formation of donor-acceptor bond, and OH-groups form hydrogen bonds with OH-groups of the residue of a molecule of epoxy oligomer in the grid. The studied intermolecular interactions of epoxyamine grid and hydroxides of amphoteric metals Al(OH)3, Fe(OH)3, Ti(OH)4 indicate the formation of low-energy inductive and dipole-dipole (orientation) bonds. It was established that existence of amphoteric hydroxides does not cause a change of the spatial conformation of the grid's fragment. It was shown that the ability of hydroxides of metals to affect the spatial conformation of a fragment of the epoxyamine grid increases in the series: Ti(OH)3<Al(OH)3<Fe(OH)3<Ca(OH)2. The resulting series coincides with the series, in which basic properties of active Branstad centers (OH-groups) with the central elements Ti4+<Al3+<Fe3+<Ca2+ increase (acidic properties decrease). The influence of the oxide filler on the structure and spatial conformation of epoxyamine grid increases with an increase of basicity (alkalinity) of an oxide. Resistance of composites to aqueous aggressive media depends on the surface acidic-basic properties, dispersion and package density of fillers' particles in the polymer matrix. When adding strongly basic calcite oxide (CL), chemical resistance of composites decreases by 5 times. In this case, composites with non-homogeneous structure and non-uniform distribution of compacted areas are formed. It was found that when adding amphoteric rutile oxides (RT), alumina (AL) and hematite (HM), the main factors that affect chemical resistance of filled composites include dispersion and package density of fillers' particles. The calculated parameter a of composites, which describes package density of the filler in the polymer matrix, increases in the series of fillers HM<RT<AL. This series coincides with the series, in which resistance of filled composites in all aggressive media decreases. At an increase in package density of a filler, probability of pegridration of aggressive medium into the material decreases, which is associated with extension of the diffusion path