scholarly journals Parameterising continuum models of heat transfer in heterogeneous living skin using experimental data

2018 ◽  
Author(s):  
Sean McInerney ◽  
Elliot J Carr ◽  
Matthew J Simpson
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Layered Structure ◽  
Experimental Studies ◽  
Synthetic Data ◽  
Spatial Location ◽  
Recent Experimental Data ◽  
Data Set ◽  
Experimental Constraint

AbstractIn this work we consider a recent experimental data set describing heat conduction in living porcine tissues. Understanding this novel data set is important because porcine skin is similar to human skin. Improving our understanding of heat conduction in living skin is relevant to understanding burn injuries, which are common, painful and can require prolonged and expensive treatment. A key feature of skin is that it is layered, with different thermal properties in different layers. Since the experimental data set involves heat conduction in thin living tissues of anesthetised animals, an important experimental constraint is that the temperature within the living tissue is measured at one spatial location within the layered structure. Our aim is to determine whether this data is sufficient to reliably infer the heat conduction parameters in layered skin, and we use a simplified two-layer mathematical model of heat conduction to mimic the generation of experimental data. Using synthetic data generated at one location in the two-layer mathematical model, we explore whether it is possible to infer values of the thermal diffusivity in both layers. After this initial exploration, we then examine how our ability to infer the thermal diffusivities changes when we vary the location at which the experimental data is recorded, as well as considering the situation where we are able to monitor the temperature at two locations within the layered structure. Overall, we find that our ability to parameterise a model of heterogeneous heat conduction with limited experimental data is very sensitive to the location where data is collected. Our modelling results provide guidance about optimal experimental design that could be used to guide future experimental studies.NomenclatureA brief description of all variables used in the document are given in Table 1.Table 1:Variable nomenclature and description.

A Multiclass Classification Method Based on Decoding of Binary Classifiers

2009 ◽  
Vol 21 (7) ◽  
pp. 2049-2081 ◽  
Author(s):  
Takashi Takenouchi ◽  
Shin Ishii
Keyword(s):  
Probabilistic Models ◽  
Experimental Studies ◽  
Synthetic Data ◽  
Multiclass Classification ◽  
Data Sets ◽  
Classification Methods ◽  
Boltzmann Machine ◽  
Data Set ◽  
New Methods ◽  
Binary Classifiers

In this letter, we present new methods of multiclass classification that combine multiple binary classifiers. Misclassification of each binary classifier is formulated as a bit inversion error with probabilistic models by making an analogy to the context of information transmission theory. Dependence between binary classifiers is incorporated into our model, which makes a decoder a type of Boltzmann machine. We performed experimental studies using a synthetic data set, data sets from the UCI repository, and bioinformatics data sets, and the results show that the proposed methods are superior to the existing multiclass classification methods.

scholarly journals Experimental studies of iron transformations kinetics and autocatalysis during its physicochemical removal from underground water

2021 ◽  
Author(s):  
S. Yu Martynov ◽  
V. L. Poliakov
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Studies ◽  
Underground Water ◽  
Model Parameters ◽  
Kinetic Coefficients ◽  
Transfer Equations ◽  
The Mathematical Model ◽  
Autocatalytic Effect ◽  
Forms Of Iron

Abstract The mathematical model of physicochemical iron removal from groundwater was developed. It consists of three interrelated compartments. The results of the experimental research provide information in support of the first two compartments of the mathematical model. The dependencies for the concentrations of the adsorbed ferrous iron and deposited hydroxide concentrations are obtained as a result of the exact solution of the system of the mass transfer equations for two forms of iron in relation to the inlet surface of the bed. An analysis of the experimental data of the dynamics of the deposit accumulation in a small bed sample was made, using a special application that allowed to select the values of the kinetic coefficients and other model parameters based on these dependencies. We evaluated the autocatalytic effect on the dynamics of iron ferrous and ferric forms. The verification of the mathematical model was carried out involving the experimental data obtained under laboratory and industrial conditions.

scholarly journals A Molecular Perspective on Water Vapour Accommodation into Ice and Its Dependence on Temperature

2020 ◽  
Author(s):  
Daniel Schlesinger ◽  
Samuel J. Lowe ◽  
Tinja Olenius ◽  
Xiangrui Kong ◽  
Jan B. C. Pettersson ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Order Parameter ◽  
Potential Temperature ◽  
Experimental Studies ◽  
Accommodation Coefficient ◽  
Recent Experimental Data ◽  
Ice Crystal ◽  
Cloud Particle ◽  
Data Set ◽  
Accommodation Process

<div> <div> <div> <p>Accommodation of vapour phase water molecules into ice crystal surfaces is a fundamental process controlling atmospheric ice crystal growth. Experimental studies investigating the accommodation process with various different techniques report widely spread values of the water accommodation coefficient on ice, αice, and the results on its potential temperature- dependence are inconclusive. We run molecular dynamics simulations of molecules condensing onto the basal plane of ice Ih using the TIP4P/Ice empirical force field and characterize the accommodated state from this molecular perspective, utilizing the interaction energy, the tetrahedrality order parameter and the distance below the instantaneous interface as criteria. Changes of the order parameter turn out to be a suitable measure to distinguish between surface and bulk states of a molecule condensing onto the disordered interface. In light of the findings from the molecular dynamics, we discuss and re- analyse a recent experimental data set on αice obtained with an environmental molecular beam (EMB) setup [Kong et al, Journal of Physical Chemistry A, 2014] using kinetic molecular flux modelling, aiming at a more comprehensive picture of the accommodation process from a molecular perspective. These results indicate that the experimental observations indeed cannot be explained by evaporation alone. At the same time our results raise the issue of rapidly growing relaxation times upon decreasing temperature, challenging future experimental efforts to cover relevant time scales. Finally, we discuss the relevance of the water accommodation coefficient on ice in the context of atmospheric cloud particle growth processes. </p> </div> </div> </div>

scholarly journals Creation of Model and Calculation of Thermal Processes in the Ring Graphite Electrode of the Plasmatron

2018 ◽  
Vol 7 (4.36) ◽  
pp. 1046
Author(s):  
Ramil T. Nasibullin ◽  
Almaz Sh. Sadriev ◽  
Ramil Sh. Sadriev ◽  
Lenar R. Sarimov
Keyword(s):  
Mathematical Model ◽  
Heat Conduction ◽  
Thermal State ◽  
Graphite Electrode ◽  
Exchange Process ◽  
Experimental Studies ◽  
Ring Electrode ◽  
Maximum Temperature ◽  
Thermal Processes ◽  
Differential Heat

This paper presents the theoretical and experimental material obtained in the study of the erosion and thermal state of the ring graphite electrode for a plasmatron. Thermal processes in graphite electrodes of plasmatrons are quite complex and multifaceted. A mathematical model of thermal processes that occur at the ring electrodes of plasmatrones has been developed. The mathematical model is based on the differential heat conduction equation for a ring electrode in cylindrical coordinates. With the use of this mathematical model, the inverse problem of heat conduction is solved: determination of the regularities of the heat exchange process by the temperatures of individual points on a solid surface. An experimental study of the temperature distribution at the end of the electrode and along the length of the electrode was carried out. Experiments have shown that the temperature on the side surfaces drops sharply towards the cold end of the electrode. When reducing the length of the electrode, the maximum temperature at the end decreases, and the temperature on the inner and outer edges of the electrode increases slightly. The most significant factors determining the temperature field at the end of the ring electrode are the power and size of the heat source. Comparison of the results of experimental studies and mathematical modeling showed a match with an acceptable degree of accuracy.   

scholarly journals Experimental studies of the method of mutual load of induction motors

2020 ◽  
pp. 44-49
Author(s):  
V. V. Kharlamov ◽  
◽  
D. I. Popov ◽  
P. S. Sokolov ◽  
L. E. Serkova ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Induction Motors ◽  
Experimental Studies ◽  
Electromechanical System ◽  
Experimental Equipment ◽  
Frequency Converters ◽  
Parameter Values ◽  
The Mathematical Model

The article presents the results of comparison of experimental studies and mathematical modeling of the stand for testing induction motors by the method of mutual load. A detailed description of the composition of the experimental equipment, which is based on a pair of frequency converters and connected to them a pair of engines of the АИС71В4 type with a nominal power of 0,75 kW, the shafts of which are rigidly connected by a coupling. The mathematical model of the electromechanical system used in the calculations is presented, and its main assumptions are listed. A table of parameter values and graphs obtained from calculated and experimental data are presented. The analysis of the obtained data shows the possibility of using the considered mathematical model with the existing assumptions in the design of electrical complexes intended for testing induction motors by the method of mutual load

scholarly journals MODELING OF SOLAR RADIATION FOR USE IN RENEWABLE ENERGY AND IN CONSTRUCTION THERMAL PHYSICS

2018 ◽  
Vol 40 (1) ◽  
pp. 44-50
Author(s):  
B.I. Basok ◽  
B.V. Davydenko ◽  
V.G. Novikov ◽  
R.Ya. Sorokovoy
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Renewable Energy ◽  
Solar Radiation ◽  
Experimental Studies ◽  
Program Code ◽  
Solar Insolation ◽  
Thermal Physics ◽  
The Mathematical Model ◽  
Design And Construction

The work is devoted to the estimation of the intensity and energy of solar radiation at the earth's surface. The aim of the research is to develop a mathematical model of solar radiation, necessary for the design of devices for renewable energy, as well as in the design and construction of buildings and structures. The mathematical model of solar radiation is realized in the Python code. The program code allows you to calculate the intensity of solar radiation and solar insolation on any day of the year. The model is verified by the results of experimental studies of solar radiation in the Odessa region and by the results of our own experimental data.

scholarly journals Numerical Modeling of Combustion and Detonation in Aqueous Foams

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6233
Author(s):  
Alexey Kiverin ◽  
Ivan Yakovenko
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Numerical Modeling ◽  
Numerical Simulations ◽  
Recent Experimental Data ◽  
Flame Acceleration ◽  
Aqueous Foam ◽  
Aqueous Foams ◽  
Transition To Detonation ◽  
Reactive Gas

Combustible aqueous foams and foamed emulsions represent prospective energy carriers. This paper is devoted to the overview of model assumptions required for numerical simulations of combustion and detonation processes in aqueous foams. The basic mathematical model is proposed and used for the analysis of the combustion development in the wet aqueous foam containing bubbles filled with reactive gas. The numerical results agree with the recent experimental data on combustion and detonation in aqueous foams containing premixed hydrogen–oxygen. The obtained results allowed for distinguishing the mechanisms of flame acceleration, transition to detonation, detonation propagation, and decay.

scholarly journals EXPERIMENTAL STUDIES OF HEAT EXCHANGE DURING WATER COOLING AND STEAM CONDENSATION IN DEMOVER RADIATOR SECTIONS

2021 ◽  
Vol 1 (38) ◽  
pp. 107-114
Author(s):  
V. Mogila ◽  
M. Kovtanets ◽  
M. Morneva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Mathematical Model ◽  
Cooling System ◽  
Experimental Studies ◽  
Road Transport ◽  
Thermal Calculation ◽  
Mode Of Operation ◽  
Simulation Results ◽  
The Mathematical Model

The Department of Railwayand Road Transport, lift and care system of Volodymyr Dahl East Ukrainian National University, an energy-saving cooling system for diesel locomotives using phase transitions of the coolant has been developed. The proposed cooling system allows to maintain constant optimal temperatures of cooling objects at ambient temperatures ± 40 ºC and in any mode of operation of the diesel engine. For thermal calculation of the radiator section operating in the mode of the steam condenser, the mathematical model of process of heat transfer from steam to walls of a flat tube at condensation is developed that considers geometrical features of section of a tube. The adequacy of this mathematical model is verified by comparing the simulation results with the obtained experimental data. During the tests, the outlet water temperature, inlet and outlet air temperature, and air pressure in front of and behind the radiator were measured. Having the values of wall temperature, steam temperature and condensate, knowing the value of steam consumption and the experimental heat transfer coefficient, it becomes possible to verify the adequacy of the mathematical model by comparing the simulation results with the obtained experimental data. Schemes of bench equipment, test methods, experimental planning and basic calculation dependences required for testing serial radiator sections of a locomotive in the standard mode of operation and in the mode of steam condensers are presented.

scholarly journals Simulation of differentiated thermal processing of railway rails by compressed air

2021 ◽  
Vol 63 (11-12) ◽  
pp. 907-914
Author(s):  
V. D. Sarychev ◽  
S. G. Molotkov ◽  
V. E. Kormyshev ◽  
S. A. Nevskii ◽  
E. V. Polevoi
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Mathematical Model ◽  
Heat Conduction ◽  
Thermal Processing ◽  
Heat Conduction Equation ◽  
Rail Steel ◽  
Rail Head ◽  
The Third ◽  
Forced Cooling

Mathematical modeling of differentiated thermal processing of railway rails with air has been carried out. At the first stage, onedimensional heat conduction problem with boundary conditions of the third kind was solved analytically and numerically. The obtained temperature distributions at the surface of the rail head and at a depth of 20 mm from the rolling surface were compared with experimental data. As a result, value of the coefficients of heat transfer and thermal conductivity of rail steel was determined. At the second stage, mathematical model of temperature distribution in a rail template was created in conditions of forced cooling and subsequent cooling under natural convection. The proposed mathematical model is based on the Navier-Stokes and convective thermal conductivity equations for the quenching medium and thermal conductivity equation for rail steel. On the rail – air boundary, condition of heat flow continuity was set. In conditions of spontaneous cooling, change in temperature field was simulated by heat conduction equation with conditions of the third kind. Analytical solution of one-dimensional heat conduction equation has shown that calculated temperature values differ from the experimental data by 10 %. When cooling duration is more than 30 s, change of pace of temperature versus time curves occurs, which is associated with change in cooling mechanisms. Results of numerical analysis confirm this assumption. Analysis of the two-dimensional model of rail cooling by the finite element method has shown that at the initial stage of cooling, surface temperature of the rail head decreases sharply both along the central axis and along the fillet. When cooling duration is over 100 s, temperature stabilizes to 307 K. In the central zones of the rail head, cooling process is slower than in the surface ones. After forced cooling is stopped, heating of the surface layers is observed, due to change in heat flow direction from the central zones to the surface of the rail head, and then cooling occurs at speeds significantly lower than at the first stage. The obtained results can be used to correct differential hardening modes.

scholarly journals THERMOELECTRIC DEVICE FOR TREATMENT PANARIATION

2019 ◽  
Vol 45 (4) ◽  
pp. 18-31
Author(s):  
V. I. Dvorjanchikov ◽  
D. A. Magomedov ◽  
K. A. Magomedova ◽  
I. Sh. Mispahov
Keyword(s):  
Mathematical Model ◽  
Heat Conduction ◽  
Heat Conduction Problem ◽  
Experimental Studies ◽  
Heat Removal ◽  
Coefficient Of Performance ◽  
Laboratory Model ◽  
Thermoelectric Device ◽  
Two Dimensional ◽  
Heat Effects

Objectives The aim of the study is to develop a thermoelectric device for the treatment of felon, its mathematical modeling, experimental tests of the laboratory model of the device, the study of thermal processes occurring in it. Method. A design of a thermoelectric device for the treatment of felon, providing the possibility of both uniform and contrasting therapeutic heat effects on the fingers is proposed. Result. A mathematical model of the device has been developed, implemented on the basis of solving a non-stationary two-dimensional heat conduction problem for a system of complex configuration with boundary conditions of the second and third kind. Experimental studies of the device were carried out on a specially designed test bench for checking the adequacy of the mathematical model. A two-dimensional non-stationary heat conduction problem was solved for a complex system with a rectangular geometry of fragments and heat sources. The temperature change of various points of the “device-object” system of exposure in space and in time at various values of the cooling and heating capacity of a thermoelectric battery (TEB) was studied. Comparison of calculated and experimental data. Conclusion. The results of research have shown the effectiveness of the use of the developed device for the implementation of thermal procedures in the treatment of felon in terms of efficiency, versatility, impact reliability, comfort and accuracy of maintaining temperature conditions. It is shown that it is possible to increase the efficiency of the device using a combination of thermopile operation modes (maximum cooling capacity and maximum coefficient of  performance), as well as improving the intensity of heat removal from its reference junctions.

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