Artykuły naukowe (SD)

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  • Miniatura
    PozycjaOpen Access
    A new magnetic-hybrid photoreactor for photocatalytic water disinfection
    (Polska Akademia Nauk, 2023-07-14) Paszkiewicz, Oliwia; Wang, Kunlei; Kordas, Marian; Rakoczy, Rafał; Kowalska, Ewa; Markowska-Szczupak, Agata; West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065 Szczecin, Poland; Hokkaido University, Institute for Catalysis (ICAT), N21, W9, 001-0021 Sapporo, Japan; West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065 Szczecin, Poland; West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065 Szczecin, Poland; Hokkaido University, Institute for Catalysis (ICAT), N21, W9, 001-0021 Sapporo, Japan; Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Krakow, Poland; West Pomeranian University of Technology in Szczecin, Faculty of Chemical Technology and Engineering, Department of Chemical and Process Engineering, Piastow 42, 71-065 Szczecin, Poland
    In this research, the removal of model gram-negative bacteria Escherichia coli and gram-positive Staphylococcus epidermidis bacteria from aqueous solutions using copper-modified titania 0.5Cu@HomoP25, 2.0Cu @HomoP25, 5.0Cu@HomoP25 in new hybrid photoreactor assisted with rotating magnetic field (RMF) was evaluated. Therefore, the analysis of variance (ANOVA) test was employed to design the experiments and to determine the optimal conditions. The effects of various parameters such as copper concentration [% w/w], time [h] and frequency of RMF [Hz] were studied. Results: Analysis of variance (ANOVA), revealed a good agreement between experimental data and the proposed quadratic polynomial model (R2=0.86 for E. coli and R2=0.69 for S. epidermidis). Experimental results showed that with increasing copper concentration, time, and decreasing frequency of RMF removal efficiency was increased. Accordingly, the water disinfection efficiency of 100% in the regression method of the independent variables: for E. coli bacteria: c = 5 %; t = 3 h; f = 50 Hz, and for S. epidermidis c = 2.5 %; t = 1.3 h; f = 26.6 Hz were optimized. This study showed that the nonlinear regression method is a useful tool for optimizing the operating parameters for the photocatalytic disinfection process.
  • Miniatura
    PozycjaOpen Access
    Antimicrobial properties of pristine and Pt-modified titania P25 in rotating magnetic field conditions
    (Elsevier B.V., 2022-08-01) Paszkiewicz, Oliwia; Wang, Kunlei; Rakoczy, Rafał; Kordas, Marian; Leniec, Grzegorz; Kowalska, Ewa; Markowska-Szczupak, Agata; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland; Institute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, Japan; Institute of Physics, Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Szczecin, al. Piastow 48, Szczecin 70-311, Poland; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland; Institute of Physics, Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Szczecin, al. Piastow 48, Szczecin 70-311, Poland; Institute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, Japan; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland
    Effective and cheap water purification is one of the most important tasks facing humanity. Among various methods of water treatment, heterogeneous photocatalysis is probably most recommended. However, the application of artificial sources of irradiation results in high investment and operating costs. Accordingly, either vis-responsive photocatalysts or different ways of photocatalyst activation should be developed. In the present study, rotating magnetic field (RMF) has been tested to inactivate gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria in the presence of pristine and Pt-modified titania P25 photocatalyst. Liquid cultures of the bacteria have been exposed to the titania and RMF (RMF frequency of 1–50 Hz, RMF magnetic induction of ca. 19.92 mT, 180 min exposure time, temperature of incubation at 37 °C). It has been found that highly active titania photocatalyst might also work in the absence of photoirradiation but under RMF. Moreover, its modification with platinum besides highly improved photocatalytic activity (tested for two model reactions of oxidative decomposition of acetic acid and anaerobic dehydrogenation of methanol under UV/vis irradiation) results in significant enhancement of antimicrobial effect under RMF. Additionally, photocatalysts with larger content of oxidized forms of platinum show higher antimicrobial activity, and thus it is proposed that platinum oxides are more active than zero-valent platinum under RMF. This study provides evidence of antimicrobial effect of titania without photoirradiation, indicating that RMF might efficiently activate photocatalyst.
  • Miniatura
    PozycjaOpen Access
    Comparison of multi-criteria decision methods for customer-centered decision making: A practical study case
    (Elsevier, 2023) Shekhovtsov, Andrii; Dobryakova, Larisa; Faculty of Computer Science and Information Technology, West Pomeranian University of Technology in Szczecin, Szczecin, Poland; Faculty of Computer Science and Information Technology, West Pomeranian University of Technology in Szczecin, Szczecin, Poland
    In this paper, we show the practical application of two recently proposed Multi-Criteria Decision Analysis (MCDA) methods, namely the Stable Preference Ordering Towards the Ideal Solution (SPOTIS) and the Reference Ideal Method (RIM) methods. Both of these methods can utilize the Expected Solution Point (ESP) concept, which allows it to easily reflect the decision-maker's or the customer's preferences and expectations. We show the comparison of those methods in the practical study case of laptop choice for the customer with specific needs and expectations for the hardware expressed using ESP. The comparison also includes rankings built toward an optimal solution to underline the necessity of such an approach as the Expected Solution Point. We also use the recently developed Ranking Comparison (RANCOM) method to identify criteria weights to include customer preferences in the weights. The paper also contains a broad discussion of the obtained results and limitations of the presented methods.
  • Miniatura
    PozycjaOpen Access
    Evaluating the Performance of Subjective Weighting Methods for Multi-Criteria Decision-Making using a novel Weights Similarity Coefficient
    (Elsevier, 2023) Shekhovtsov, Andrii; Faculty of Computer Science and Information Technology, West Pomeranian University of Technology in Szczecin, Szczecin, Poland
    In every decision-making problem which involves two or more criteria, there is to identify the relative importance of those criteria in order to make a proper decision. Very often, a decision-makers employee, for this purpose, subjective weighting methods, such as Analytic Hierarchy Process (AHP) or RANking COMparison (RANCOM). However, there is no simple way to compare the quality of the weights identification using different methods. To address this issue, this paper proposes a simple but efficient Weights Similarity Coefficient, which allows us to evaluate the relative performance of different subjective weighting methods. Furthermore, we propose a framework that utilizes the proposed coefficient in order to provide more complete comparison results.To demonstrate the applicability and effectiveness of the proposed framework, a case study is performed to compare two popular weighting methods: AHP and RANCOM. The results of the comparison prove that proposed coefficient with the combination of the proposed framework is an efficient instrument for weighing methods comparison.