Ukrainian Journal of Mechanical Engineering and Materials Science
Permanent URI for this communityhttps://ena.lpnu.ua/handle/ntb/31565
Browse
4 results
Search Results
Item Optimization of oligonucleotides characteristics with topsis(Видавництво Львівської політехніки, 2023-02-28) Javanbakht, Taraneh; Concordia UniversityThis paper focused on a new application of the TOPSIS method for the prediction and optimization of the oligonucleotides characteristics. This method has been used for these purposes as it has shown its efficacy for these analyses. This is the first time that it has been applied to the investigation of these biomolecules. The hypothesis in this paper was that the characteristics of these biomaterials would be optimized according to their structural differences. The obtained results showed that the stabilization of oligonucleotides would affect their ranking with TOPSIS when the stability of these biomolecules increased against enzymes in their structure. In other words, the oligonucleotides with less enzymatic degradation were ranked better with this method. This study showed the first application of this algorithm for the prediction and optimization of the oligonucleotides’ characteristics. The results in this work revealed that the ranks of candidates depended on their distances from their ideal solutions. This showed that TOPSIS could be used as an appropriate method in the optimization of oligonucleotides as the rankings with this method would coincide with the data that concern the stability of these biomolecules against enzymatic degradation. The results of this work could be applied for the preparation of novel materials with applications in science and engineering.Item Investigation of rheological properties of a nanocomposite of superparamagnetic iron oxide nanoparticles with polyethylene glycol(Видавництво Львівської політехніки, 2023-02-28) Javanbakht, Taraneh; Concordia UniversityThis paper presents the results of a new investigation of the rheological properties of a nanocomposite of superparamagnetic iron oxide nanoparticles (SPIONs) with polyethylene glycol (PEG). The surface of the nanocomposite had no electrical charge and the SPIONs were coated with the polymer. The investigations were performed at different temperatures and the results were compared on different rheological parameters. The steady-state behavior of samples was observed at 20 °C and 40 °C and a small increase of viscosity versus shear strain, shear rate or time was revealed at 60 °C. Moreover, the shear stress increase was observed with the increase of shear rate and shear strain. The slopes of the corresponding changes were higher at 20 °C and decreased with the increase in temperature. The torque values increased with shear strain and time. The same phenomenon concerning the different slopes at different temperatures was observed for the torque-shear strain and torque-time variations. These results showed that the rheological properties of the nanocomposite depended on the temperature and could change with the temperature increase. An advantage of this study was that the comparative investigation of the rheological properties of nanocomposite at different temperatures was carried out. The other advantage was that the effect of the coating of the SPIONs with the polymer was observed in the obtained results. This new investigation of the nanaocomposite of SPIONs-PEG coated with PEG can provide comparative data for more investigations of the surface charged SPIONs coated with this polymer. These studies can provide information for a further investigation of the effect of the surface charge of SPIONs in the polymeric matrix on their rheological properties.Item Optimization of physical instruments’ characteristics with topsis(Видавництво Львівської політехніки, 2022-02-22) Javanbakht, Taraneh; Concordia University; University of Quebec in MontrealThe present study focuses on the characteristics optimization of the physical instruments with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The hypothesis in this research work was that the characteristics of spectrometers and rheometers could affect their rankings, which in turn could be influenced by the underestimation of their cost criterion. In this paper, the characteristics optimization of the FTIR spectrometers and rheometers was carried out with TOPSIS. Moreover, its modified algorithm was also used in order to analyze the inappropriate consideration of these instruments due to category confusion. The modification of TOPSIS helped obtain an automated decision-making method for the treatment of data. The results showed that the rankings of the FTIR spectrometers and rheometers were different as expected. Moreover, the rankings of the FTIR spectrometers were different with using the unmodified and modified TOPSIS; however, that of the rheometers did not change. The change in the ranking of the FTIR spectrometers was due to the application of the fuzzy disjunction in the TOPSIS code. In this case, the first and second candidates were placed in the first and second positions, respectively, whereas the second candidate had a better rank than the first one in the analysis with the unmodified TOPSIS code. The rank improvement of the first candidate in the category of FTIR spectrometers after the modification of the TOPSIS code was also observed. The results of this work can be used in mechanical engineering and materials science as the appropriate use of instruments in these fields depends on the consideration of their characteristics for which their optimization in comparison with those of other instruments could provide interesting results. Such investigations would provide complementary data for the experimental approaches in further applications.Item Investigation of rheological properties of graphene oxide and its nanocomposite with polyvinyl alcohol(Lviv Politechnic Publishing House, 2021) Javanbakht, Taraneh; Department of Physics, Concordia University, Richard J. RenaudThis paper focuses on the rheological properties of graphene oxide (GO) and its nanocomposite with polyvinyl alcohol (PVA). The purpose of this paper is to compare the mechanical properties of these materials. GO is a nanomaterial that has been widely studied in engineering. The comparison of its rheological properties with those of its nanocomposite with PVA has been required. Rheology is an appropriate method for the comparative investigation of the mechancial behavior of these materials. The challenge has been to compare the rheological parameters of these materials regarding their mechanical properties. This investigation shows that GO and GO-PVA do not exhibit the same viscosity change at low shear rates. While GO shows a significant decrease of viscosity, GO-PVA shows a steady state behavior at these shear rates. However, both GO and GO-PVA show a constant viscosity at high shear rates. These materials show the same behavior concerning the change of their viscosity versus shear strain or time. The changes of torque versus shear strain and time for GO and GO-PVA are representes as increasing curves and lines, respectively. The increase of shear stress versus shear rate or shear strain coincide for both materials. Powever, as expected, the first change represents an increasing line and the second one a curve. This original investigation shows the difference between the mechanical behaviour of GO and GO-PVA concerning the change of their viscosity at low shear rates and their similarity at high shear rates. Moreover, this study gives new results concernig the change of other parameters as described above. The unique physicochemical properties of GO have made it an important candidate in engineering and materials science. This investigation can lead to a better understanding of the rheological properties of GO and GO-PVA for the improvement of these applications.