Periodica Polytechnica (Budapest University of Technology and Economics)
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Full text linkOleiwi, A. H., Jabur, A. R., Alsalhy, Q. F., Zeinedini, A. "Crude Oil Desulfurization by Polystyrene/Graphene Nanocomposite Membranes", Periodica Polytechnica Chemical Engineering, 2025.https://doi.org/10.3311/PPch.38227When the above article was first published online the fourth affiliation was incorrect. This has now been corrected in the online version. The correct version of the fourth affiliation is published here
Numerical Study of the Optimal Position of Corona Wires in Two Types of ESP
Full text linkIn recent years, particulate emissions have advanced to the top of the global priority list. Numerous research, both numerical and experimental, have been conducted to explore different corona wires and collecting plate configurations. This study aims to investigate the best location of corona wires arrangements using 3 types of collecting plates; wavy plates (wavyPs), and inverted wavy plates (InvwavyPs), flat plates (FPs) as a reference case. Where, three positions of corona arrangements were modelled with three types of collecting plates via Finite Element Method (FEM)
An Experimental Assessment and Numerical Simulation of the Corrosion Behavior of Aluminum Welded Joints in Diverse Environments
Full text linkThe corrosion behavior of stud-welded AA5083-H321/AA6061-T6 joints was examined. The electrochemical demeanor of the resultant joint was scrutinized in 3.5% NaCl, ASTM seawater, and Na2SO4 solutions using scanning electron microscopy (SEM), optical microscopy (OM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). COMSOL Multiphysics version 5.6 software was used to predict the galvanic corrosion of AA5083-H321/A6061-T6 in different solutions, using the software finite element (FE) kit. The results indicated that drawn arc stud welding (DASW) enhanced the corrosion resistance of the welding zone, with the highest resistance observed in the Na2SO4 solution. This process also influenced the pitting corrosion rate and minimized alterations in pit morphology, with the order of corrosion resistance decreasing from Na2SO4 to 3.5% NaCl and ASTM seawater. Among the base metals, the AA6061-T6 side of the weld exhibited superior corrosion resistance compared to the AA5083-H321 side across all tested solutions. The results from the numerical simulation of the corrosion behavior of the welded joint support the experimental assessment
Evaluating Surface Roughness of Ductile Cast Iron Machined by EDM Using Solid and Hollow Cylindrical Copper Electrodes
Full text linkThis study reports a comparative analysis to evaluate the performance of solid cylindrical and hollow cylindrical copper electrodes in terms of average surface roughness 'Ra' for machining ductile cast iron (DCI) using the electrical discharge machining (EDM) process. Experiments were conducted by varying the peak current, spark-on duration, spark-off duration, and flushing pressure according to Taguchi's L9 (43) orthogonal array experimental design matrix. Nine experiments were conducted using each tool electrode. Thus, a total of eighteen experiments were performed in this study. It was found that surface roughness increased with an increase in peak current and spark-on duration and decreased with an increase in spark-off duration and flushing pressure. Peak current and spark-on duration have a significant influence on surface roughness. Analysis of variance (ANOVA) was employed to identify substantial EDM variables and to develop a model for predicting the average surface roughness. The interaction graphs show the relationships between the considered EDM variables. Microstructural analysis of the best-finished machined surfaces was conducted using a scanning electron microscope (SEM). The SEM micrographs reveal that irregular, deeper, and non-uniform craters are formed on the DCI surface machined with the hollow cylindrical copper electrode. This comparative study concluded that the solid cylindrical copper electrode produced lower surface roughness than the hollow cylindrical copper electrode. Thus, a better surface finish of DCI can be achieved by EDM using the solid cylindrical copper electrode
Current trends in library and information science in the light of PhD research and studies – 2.: Interview with Bea Winkler
No full textThe editorial team of CELISR conducted a short interview with recent graduates of the Library and Information Science doctoral program at the ELTE Doctoral School of Literary Studies, in order to provide the journal’s readers with an insight into the current and future scientific activities of researchers, and to give an idea of the current research trends in the field. The following article contains a brief overview of the PhD research conducted by Bea Winkler, Library Director General at Hutÿra Ferenc Library, Archives and Museum, University of Veterinary Medicine Budapest, and Assistant Lecturer at Institute of Library and Information Science, Faculty of Humanities, Eötvös Loránd University, with background and future prospects.The editorial team of CELISR conducted a short interview with recent graduates of the Library and Information Science doctoral program at the ELTE Doctoral School of Literary Studies, in order to provide the journal’s readers with an insight into the current and future scientificactivities of researchers, and to give an idea of the current research trends in the field. The following article contains a brief overview of the PhD research conducted by Bea Winkler, Library Director General at Hutÿra Ferenc Library, Archives and Museum, University of Veterinary Medicine Budapest, and Assistant Lecturer at Institute of Library and Information Science, Faculty of Humanities, Eötvös Loránd University, with background and future prospects
Integration of Simulation and Experimental Approaches for Optimizing TiO2 Nanowire/Fe2O3 Modified Polyethersulfone Membranes in Dye Removal Applications
Full text linkThis study aimed to mimic and optimize polyethersulfone (PES) membrane performance for dye separation applications. Bulk modification was conducted, harnessing titanium dioxide nanowire/iron oxide (TiO2 NW/Fe2O3) to improve water flux, dye removal efficiency, and antifouling properties. Membranes were fabricated with varying nanostructure concentrations (0.1-0.7 g) and examined under different pH levels (3-12) and dye concentrations (25-100 mg/L). Utilizing the response surface methodology (RSM), the process conditions optimized with ANOVA confirmed the adopted model reliability (R2 = 0.9668 for flux, 0.9809 for rejection). Experimental results revealed that 0.7 g of TiO2 NW/Fe2O3 achieved the highest performance, recording 93 L/m2∙h flux and >99% naphthol blue black dye rejection. Besides, increasing nanostructure content has enhanced the membrane porosity and hydrophilicity. Meanwhile, acidic conditions (pH 3-5) facilitated stronger dye–membrane interactions, while alkaline pH reduced the retention efficiency. Simulation results validated the experimental findings, bestowing deeper insights into the dye separation mechanisms. These findings highlighted the potential of TiO2 NW/Fe2O3-modified PES membranes as a promising candidate for wastewater treatment applications
Effect of Graphene Oxide on the Mechanical, Thermal, and Fire-retardant Properties of Carbon Fiber Reinforced Epoxy Composites
Full text linkThe utilization of carbon fiber reinforced polymer (CFRP) composites has garnered considerable interest due to their lightweight characteristics, exceptional strength, and improved chemical resistance. This study examines CFRP composite's mechanical and thermal performance, emphasizing the influence of epoxy resin and graphene oxide (GO) on improving structural qualities. CFRP is extensively utilized in aerospace, automotive, and civil engineering sectors, especially for structural reinforcement and restoration. This study investigates the impact of GO ranging from 0, 0.05, 0.1, 0.3, and 0.5 wt.% on CFRP laminates mechanical characteristics produced via the hand layup technique with bidirectional plies. Mechanical testing, performed by ASTM standards, demonstrated that including GO enhanced composite density, tensile strength, and flexural strength owing to improved interfacial bonding. Fourier-transform infrared spectroscopy confirmed strong chemical interactions through characteristic peaks of carbonyl and ether groups. Thermogravimetric analysis and differential scanning calorimetry revealed enhanced thermal stability and increased glass transition temperatures from 102.31 °C for neat CFRP to 163.16 °C at 0.3 wt.% GO. Furthermore, GO demonstrated fire-retardant characteristics, markedly decreasing self-extinguishing duration by 33% and combustion rate. At 0.3 wt.% GO tensile strength increased by 24.5%, flexural strength by 21.3%, and impact strength by 18.7% compared to neat CFRP. The findings indicate that CFRP laminates reinforced with 0.3 wt.% GO content exhibit enhanced mechanical performance and fire resistance, rendering them appropriate for advanced structural applications in civil engineering and other fields
Preparation and Morphology Study of Electrospun Cellulose Acetate Fibers Using Various Solvent Systems and Concentrations
Full text linkThis research investigates the application of electrospinning in the production of CA fibers and examines how two critical parameters influence the morphology and dimensions of the resulting CA products during the spinning process. These factors include the solvent system employed and the concentration of the solution. By analyzing these parameters, the research aims to elucidate their effects on the characteristics of the resultant CA materials following the spinning process. The study employed acetone as a single-solvent system, while acetone–acetic acid (2:1) and acetone-chloroform, N,N-dimethylformamide (DMF) (2:1) were used as mixed-solvent systems at room temperature. For the single-solvent approach, CA was dissolved in acetone at concentrations of (5, 10, 11, 13, and 15 wt%). In the co-solvent systems, CA was dissolved in acetone–DMF (2:1) at concentrations of (5, 10, 15, 16, 18, and 20 wt%), and in acetone-acetic acid (2:1) at concentrations of (5, 10, 15, and 20 wt%). Although DMF and acetic acid could dissolve CA to form clear solutions (at 5 wt%), electrospinning primarily resulted in discrete beads. In contrast, electrospinning CA in acetone produced short, beaded fibers. The optimal results, yielding continuous fibers without beading, were achieved with 10 wt% CA in acetone, 15 wt% CA in acetone/acetic acid (2:1), and 18 wt% CA in acetone/DMF (2:1). The results revealed how various parameters affected the diameter and quality of the fibers, ultimately determining the optimal conditions
Influence of nZnO on Enzyme-mediated PAH-removal from Contaminated Soil
Full text linkPolycyclic aromatic hydrocarbons are persistent and carcinogenic pollutants that can accumulate in the soil. In order to eliminate them, the implementation of enzyme-based bioremediation is a viable solution. Recently, there has been growing interest in nano-bioremediation, the combined use of enzymes and nanoparticles. In this study, we investigated the potential of nZnO at concentrations of 200 and 1000 mg/kg to enhance the efficiency of gentisate dioxygenase and catalase peroxidase enzymes for PAH degradation. Our results showed that nZnO doses had a positive effect on the degradation of PAHs by enzymes. The a-gentisate 1,2-dioxygenase with 200 mg/kg nZnO proved to be the most efficient for PAH removal, especially for naphthalene, as in this case it had 93.5% removal efficiency. Although the complex mechanisms behind the effects remain to be explored, our results indicate the synergistic potential of using nZnO and enzyme-based bioaugmentation in combination to achieve effective removal of specific PAH contaminants
Coexisting with Disasters: A State-of-the-art Review of Resilience Assessment of Steel Structures under Extreme Hazards
Full text linkThe current era of structural design prioritizes safety, performance, and compliance with evolving standards. While these advancements have undoubtedly improved structural integrity, safety is no longer sufficient. The increasing frequency and intensity of natural disasters, including seismic events and tornadoes, along with human-induced hazards, such as blasts, demand a broader and more adaptive design philosophy. This paradigm is resilience, a concept that not only addresses immediate structural survival but also considers recovery, functionality, and the broader physical, social, and economic impacts of disasters. Resilience-based design surpasses conventional approaches by accounting for indirect consequences, such as downtime and cascading effects, and emphasizing recovery and long-term societal well-being. This paper presents a state-of-the-art review of resilience assessment for steel structures subjected to lateral loads from seismic, blast, and tornado hazards. Which impose significant demands on structural integrity and resilience due to the extreme forces they exert, making them critical in resilience assessment. The limitations of current design codes, such as the Eurocode, are critically examined, focusing on their emphasis on life safety over recovery and their lack of multi-hazard frameworks. Future directions are explored, including the adaptation of design codes to incorporate multi-hazard resilience, the integration of advanced materials, and the development of quantifiable resilience metrics. By addressing these challenges, this paper emphasizes the need to transform structural engineering to ensure that steel structures can coexist with disasters. The insights presented aim to promote the development of novel approaches and methodologies that enhance resilience as a core principle in structural steel design