ROZPROSZONA METODA DO SYMULACJI STANÓW PRZEJŚCIOWYCH DYNAMICZNIE UWZGLĘDNIAJĄCA DODATKOWE WYNIKI AUTONOMICZNYCH AGENTÓW PROGRAMOWYCH

Based on autonomous software agents capable of calculating individual numerical field problems, a distributed method for solving transient field problems is presented. The software agents are running on distributed resources connected via a network and represent a dynamic calculation environment. Communication and data exchange between multiple agents enables their collaboration and allows decisions based on distributed overall knowledge. As unique characteristics, no central unit influences the solution process at any time. The presented simulation example and its evaluated calculation process proves the method to benefit from redundant resources.W oparciu o autonomiczne agenty programowe zdolne do obliczania indywidualnych numerycznych problemów pola, przedstawiono rozproszoną metodę rozwiązywania stanów przejściowych pola. Agenty programowe działają na zasobach rozproszonych połączonych za pośrednictwem sieci i reprezentują środowisko obliczeń dynamicznych. Komunikacja i wymiana danych między wieloma agentami umożliwia ich współpracę i pozwala podejmować decyzje w oparciu o rozproszoną wiedzę ogólną. Jako unikalna charakterystyką jest fakt, że żadna jednostka centralna nie wpływa w żadnym momencie na proces rozwiązania. Przedstawiony przykład symulacji i jej oszacowany proces obliczeniowy dowodzi, że metoda umożliwia korzystanie z nadmiarowych zasobów

Modeling Radiation-Induced Segregation in Ferritic-Martensitic Steels

As ferritic-martensitic (FM) steels receive increasing interest, due to the development of Generation IV fission reactors and fusion reactors, it is imperative to understand how the metals will behave under irradiation. Of the radiation effects, radiation-induced segregation (RIS) is of particular concern as it can lead to the formation of intermetallic phases, stress corrosion cracking, and other detrimental effects. However, predicting RIS in FM steels is more complex due to the lack of consistent trends in experimental results. Therefore, we developed a program to simulate RIS in FM alloys. By performing a sensitivity analysis of the input parameters, we found the model to be most sensitive to the defect migration energies. Although the general Chromium (Cr) concentration profile appeared to follow that of experiments, the dose dependence and bulk Cr concentration dependence were not accurately reproduced, and it became obvious that the IK model may be too simple and too sensitive to the input parameters to accurately predict all of the effects of the segregation of Cr

Systematic Development and Validation of Predictive Models for the Removal of Indoor Gaseous Pollutants using Carbon-Based Filters

Adsorbent media, which utilize physisorption and/or chemisorption to remove gaseous pollutants, are the most commonly employed technology for indoor air purification. The primary challenge associated with this technology is the saturation or exhaustion of the filter. Since conducting tests at low indoor concentrations (ppb level) is time-consuming and costly, it is necessary to develop models that can predict the service life of adsorbent filters based on experimental data obtained at high concentrations. The main purpose of this research is to estimate the performance of activated carbon filters in removing a mixture of ozone and VOCs. Three VOCs with various properties, namely limonene, toluene, and methyl ethyl ketone, were selected. To achieve the final goal, models were developed progressively for the individual components (ozone or VOC) as well as for the VOC binary mixture. The unknown parameters of these models were determined using experimental data obtained from a bench-scale setup at ppm concentration levels. Subsequently, the models were validated at lower concentrations, a higher velocity, and on a full-scale setup. Pore gas-phase and surface diffusion were the dominant mass transfer steps for intraparticle mass transfer of zone and VOCs, respectively. On the other hand, axial dispersion was important in the interparticle mass transfer of all components. Furthermore, a first-order chemical reaction and a polynomial function effectively described the reactions involving fresh activated carbon and ozone, as well as the parallel deactivation of activated carbon through chemisorption and catalytic processes. Using the information derived from modelling the removal of ozone, single VOCs, and binary mixtures of VOCs, the filter's performance was further modelled for the removal of binary and ternary mixtures of ozone and VOCs. The proposed model considers the generation of by-products resulting from the heterogeneous reaction between ozone and the reactive VOC (limonene) on the carbon surface. The rate constant for this heterogeneous reaction, formulated upon the Eley-Rideal mechanism, was determined by fitting the model to the experimental data. The obtained reaction constant was then used to validate the model's ability for binary and ternary mixtures of ozone and VOCs at typical indoor concentrations