scholarly journals Some aspects of environmental hazard due to uranium mining in Ukraine

2021 ◽  
Vol 30 (1) ◽  
pp. 34-42
Author(s):  
Tamara V. Dudar ◽  
Olga V. Titarenko ◽  
Alla N. Nekos ◽  
Olena V. Vysotska ◽  
Andrii P. Porvan
Keyword(s):  
Mathematical Model ◽  
Uranium Content ◽  
Uranium Mining ◽  
Environmental Hazard ◽  
Model Parameters ◽  
Dust Pollution ◽  
Potential Threat ◽  
Space Images ◽  
Natural Origin ◽  
Waste Dumps

Some aspects of environmental hazard within uranium mining areas are considered. The uranium content in the environment components (rocks, soils, underground and surface waters) of the central part of the Ukrainian Shield within and beyond the uranium mining area is analyzed on the example of the Michurinske ore field. It is emphasized that man-made sources of natural origin should be considered more broadly than just waste dumps from uranium mining and processing enterprises. These are sources of ionizing radiation of natural origin, which have been subjected to concentration or their accessibility has been increased because of anthropogenic activity. Additional irradiation to the natural radiation background is formed. Waste dumps of uranium mining are considered as sources of potential dust pollution in the surface layers of atmosphere with fine dust containing uranium, its decay products and associated elements. The area of waste dumps is calculated using space images. Uranium accumulates in the dusty fraction, where its content is 0.01-0.06%. Taking into account the geological and geochemical characteristics of uranium deposits, radioactive elements, heavy metals and other associated elements of uranium mineralization are car- ried out of the dumps by winds and atmospheric waters with their subsequent migration into environment components. A mathematical model of potential dust air pollution in the area of long-term operation of the oldest uranium mine is presented for the summer 2019. In total, 15 factors influencing the potential threat of air dust pollution are considered and analyzed. The mathematical model is developed on the basis of the method of discriminant functions. To assess the degree of the model parameters informativeness, one-factor covariance analysis is used. It allows assessing the degree of a single sign influence on the prediction result. The developed model takes into account the area of waste dumps, uranium content in the dust fraction and wind direction southeast and/or east as the most hazardous for the study area. The model allows determining correctly the level of potential threat of air dust pollution in 96.3% ± 3.6% of all cases.

On the displacements of the contours of the optic-electronic space images. Mathematical modeling of displacement

2017 ◽  
Vol 992 (4) ◽  
pp. 32-38 ◽  
Author(s):  
E.G. Voronin
Keyword(s):  
Mathematical Modeling ◽  
Remote Sensing ◽  
Mathematical Model ◽  
Point Of View ◽  
Design Features ◽  
Space Images ◽  
Electronic Imaging ◽  
Measuring Accuracy ◽  
Physical Laws

The article opens a cycle of three consecutive publications dedicated to the phenomenon of the displacement of the same points in overlapping scans obtained adjacent CCD matrices with opto-electronic imagery. This phenomenon was noticed by other authors, but the proposed explanation for the origin of displacements and the resulting estimates are insufficient, and developed their solutions seem controversial from the point of view of recovery of the measuring accuracy of opticalelectronic space images, determined by the physical laws of their formation. In the first article the mathematical modeling of the expected displacements based on the design features of a scanning opto-electronic imaging equipment. It is shown that actual bias cannot be forecast, because they include additional terms, which may be gross, systematic and random values. The proposed algorithm for computing the most probable values of the additional displacement and ways to address some of the systematic components of these displacements in a mathematical model of optical-electronic remote sensing.

scholarly journals The identification of a device based on a Peltier element by the least squares method

2020 ◽  
pp. 17-27
Author(s):  
Vladimir Grinkevich ◽  
Keyword(s):  
Mathematical Model ◽  
Least Squares ◽  
Least Squares Method ◽  
Control Object ◽  
Object Identification ◽  
Model Parameters ◽  
Peltier Element ◽  
Transport Delay ◽  
Non Linear ◽  
The Mathematical Model

The evaluation of the mathematical model parameters of a non-linear object with a transport delay is considered in this paper. A temperature controlled stage based on a Peltier element is an identification object in the paper. Several input signal implementations are applied to the input of the identification object. The least squares method is applied for the calculation of the non-linear differential equitation parameters which describe the identification object. The least squares method is used due to its simplicity and the possibility of identification non-linear objects. The parameters values obtained in the process of identification are provided. The plots of temperature changes in the temperature control system with a controller designed based on the mathematical model of the control object obtained as a result of identification are shown. It is found that the mathematical model obtained in the process of identification may be applied to design controllers for non-linear systems, in particular for a temperature stage based on a Peltier element, and for self-tuning controllers. However, the least square method proposed in the paper cannot estimate the transport delay time. Therefore it is required to evaluate the time delay by temperature transient processes. Dynamic object identification is applied when it is required to obtain a mathematical model structure and evaluate the parameters by an input and output control object signal. Also, identification is applied for auto tuning of controllers. A mathematical model of a control object is required to design the controller which is used to provide the required accuracy and stability of control systems. Peltier elements are applied to design low-power and small- size temperature stage . Hot benches based on a Peltier element can provide the desired temperature above and below ambient temperature.

scholarly journals A mathematical model of common-cold epidemics on Tristan da Cunha

1971 ◽  
Vol 69 (3) ◽  
pp. 423-433 ◽  
Author(s):  
B. J. Hammond ◽  
D. A. J. Tyrrell
Keyword(s):  
Mathematical Model ◽  
Common Cold ◽  
Average Duration ◽  
Model Parameters ◽  
Epidemic Threshold ◽  
Tristan Da Cunha ◽  
Simulation Techniques ◽  
Time Courses ◽  
The Mathematical Model ◽  
Computer Simulation Techniques

SUMMARYRecords of seven common-cold outbreaks on the island of Tristan da Cunha are compared with the corresponding time courses given by the mathematical model of Kermack & McKendrick (1927) and with an alternative model that directly involves a constant average duration of individual infection. Using computer simulation techniques the latter model is shown to be preferred and is then closely matched to the field data to obtain values for the model parameters. Consideration is then given to the intensity of epidemics predicted by the model and to the distribution of the actual epidemics relative to the theoretical epidemic threshold.

Abstract WMP85: Recovery Rate vs. Recovery Capacity: A Mathematical Model and its Implications for Rehabilitation

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Adam B Schweber ◽  
Lauren E Dunn ◽  
Andrea R Lendaris ◽  
Brandon M Minzer ◽  
Ronald M Lazar ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Recovery Rate ◽  
Goodness Of Fit ◽  
Recovery Period ◽  
Stroke Onset ◽  
Motor Deficit ◽  
Model Parameters ◽  
Stroke Severity ◽  
Recovery Capacity ◽  
Rate Dynamic

INTRODUCTION: Recovery of most hemiparetic patients at 90 days can be well predicted as a fixed proportion (70%) of initial motor deficit. However, recent work has shown considerable variability in the rate of recovery among proportional recoverers, prompting consideration of whether rate of recovery and recovery capacity are independent and whether a single rate dynamic governs proportional recovery. HYPOTHESIS: Among proportional recoverers, recovery rate variability can be accounted for by a single mathematical model in which: 1) recovery rate is independent of recovery capacity and 2) recovery has a sigmoid trajectory parameterized only by initial stroke severity. METHODS: We studied 23 patients with first-ever unilateral hemiparetic stroke previously identified as proportional recoverers. Fugl-Meyer Upper Extremity Motor Exam (FM-UE) had been measured at <72h, 1 week, and 90 days. A non-linear model predicting patients’ FM-UE score at any time after stroke onset was posited and model parameters were estimated by regressing one-week FM-UE scores against initial scores. Statistical significance and goodness of fit were evaluated. RESULTS: The model accounted for 86% of variability in motor recovery achieved by patients at 1 week after stroke onset (pseudo-R 2 =0.863, F 23,21= 418.0, p <.0001) and predicted that more severely impaired patients will have a slower maximum recovery rate and a recovery period that is longer in duration and more delayed in onset. CONCLUSION: The model provides evidence that proportional recovery is governed by a single rate dynamic and that recovery rate is independent of recovery capacity. It provides a tool for predicting motor impairment at any time following stroke onset and suggests a framework for characterizing the biology of recovery and the role of therapeutic interventions as either capacity-enhancing or rate-enhancing.

scholarly journals The generation of a mathematical model of the biogas production process from organic municipal solid waste

2020 ◽  
Vol 180 ◽  
pp. 02019 ◽  
Author(s):  
Marzhan Temirbekova ◽  
Madina Aliyarova ◽  
Iliya Iliev ◽  
Aliya Yelemanova ◽  
Saule Sagintayeva
Keyword(s):  
Mathematical Model ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Biogas Plant ◽  
Model Parameters ◽  
Biochemical Processes ◽  
Biogas Plants ◽  
The Mathematical Model

This paper justifies the efficiency of the biogas collection and utilization at the MSW (municipal solid waste) landfill in Almaty with the installation of several modern biogas plants. The optimal mode of processes occurring in a biogas plant is determined by computer generated simulations. Mathematical model parameters were identified to describe biochemical processes occurring in a biogas plant. Two approaches are used to resolve the mathematical model: the finite-difference method for solving the system of differential equations and simulation modeling by using the Any Logic package. A program is written in the algorithmic language C ++. Numerous calculations were carried out, the results of which are presented in curves and their qualitative picture is consistent with the ongoing processes. The created computer program allows to make a preliminary forecast of anaerobic fermentation occurring in the bioreactor depending on volume of the substrate, methane microorganisms and temperature conditions.

A Universal Mathematical Model for a New Combined-Cycle, Fossil-Fuel Power System (LAJ Cycle): Part 1 — Static Model

2002 ◽  
Author(s):  
Roddie R. Judkins ◽  
Timothy R. Armstrong ◽  
Solomon D. Labinov
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Methane Conversion ◽  
Fossil Fuel ◽  
Dynamic Models ◽  
Static Model ◽  
Combined Cycle ◽  
Model Parameters ◽  
Lagrangian Multiplier ◽  
Molar Ratios

A universal mathematical model (UMM) has been developed and applied to the LAJ (for Labinov, Armstrong, and Judkins) cycle, a new combined-cycle, fossil-fuel power system. The UMM includes static and dynamic models of the system. The static model allows for thermodynamic and thermochemical analyses of the basic system components (reformer, turbine, membrane separator, fuel cell, air compressor, heat exchanger, and other components) and the entire system. Equilibrium compositions of reforming products are defined by minimizing Gibbs free energy of the mixtures using the Lagrangian multiplier method. The dependence of the main system parameters on pressure (P), temperature (T), and water-to-methane molar ratios (N) at the steam reformer have been evaluated. For selected reforming parameters, viz., P = 4.0 MPa and T = 1200 K, the degree of methane conversion is near 95% with N = 5. However, in view of mass and size limitations on equipment, a lower value of N = 3 is preferred, in which case the degree of methane conversion is 88%. The dependence of the system static model parameters on N has been investigated, and economic characteristics of the model have been evaluated for an output power of 250 kW. It is shown that when, N = 3, the fuel cost contribution to overall electricity costs is 1 cent/kWh.

Studying Dynamic Behaviour of Flexible Rotors With an Analytic Model That Includes Non-Linear Supports, Non-Stiff Support Structure and Torsion Flexibility

2007 ◽  
Author(s):  
Heller G. Sa´nchez A. ◽  
Jesu´s M. Pintor B.
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Mathematical Formulation ◽  
Model Parameters ◽  
Analytic Model ◽  
Support Structure ◽  
Stationary Response ◽  
Rigid Structure ◽  
Flexible Rotors

This article presents a mathematical formulation based on FEM for the dynamic analysis of flexible rotors that are not grounded necessary to a rigid structure. Furthermore, it uses the component synthesis in order to introduce the behavior of the structure where the rotor is grounded. The developed mathematical model calculates the model parameters stationary response.

Model-Based EEG Analysis: Proposal and Verification of Mathematical Model for Application to Neurotechnology

2019 ◽  
Author(s):  
Kenyu Uehara ◽  
Takashi Saito
Keyword(s):  
Mathematical Model ◽  
Binary Classification ◽  
Least Square ◽  
Mental Condition ◽  
Support Vector ◽  
Model Parameters ◽  
Eeg Analysis ◽  
Analysis Method ◽  
Model Based ◽  
Proposed Model

Abstract We have modeled dynamics of EEG with one degree of freedom nonlinear oscillator and examined the relationship between mental state of humans and model parameters simulating behavior of EEG. At the IMECE conference last year, Our analysis method identified model parameters sequentially so as to match the waveform of experimental EEG data of the alpha band using one second running window. Results of temporal variation of model parameters suggested that the mental condition such as degree of concentration could be directly observed from the dynamics of EEG signal. The method of identifying the model parameters in accordance with the EEG waveform is effective in examining the dynamics of EEG strictly, but it is not suitable for practical use because the analysis (parameter identification) takes a long time. Therefore, the purpose of this study is to test the proposed model-based analysis method for general application as a neurotechnology. The mathematical model used in neuroscience was improved for practical use, and the test was conducted with the cooperation of four subjects. model parameters were experimentally identified approximately every one second by using least square method. We solved a binary classification problem of model parameters using Support Vector Machine. Results show that our proposed model-based EEG analysis is able to discriminate concentration states in various tasks with an accuracy of over 80%.

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