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  • Effects of preheating on laser beam–welded NSSC 2120 lean duplex steel
    • Michał Landowski
    • Soma Csaba Simon
    • Csaba Breznay
    • Dariusz Fydrych
    • Balázs Varbai
    2024 Pełny tekst INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY

    Duplex stainless steels show sustainable alternative for the conventional austenitic grades, with higher strength, higher resistance against stress corrosion cracking, and lower purchase cost. Thus, duplex stainless steel gains more attention in construction, oil and gas, and chemical industries. Among duplex stainless steels, low nickel and low molybdenum alloyed lean duplex stainless steel are a cost-efective substitution of austenitic grades. However, keeping the balanced ferrite/ austenite phase ratio in the weld metal can be challenging, mostly for autogenous and low heat input welding processes. In our research, a newly developed NSSC 2120 lean duplex stainless steel grade was welded autogenously by fber laser welding process. Diferent welding parameters and preheating temperatures were used during the experiments. The welds were evaluated by microscopic and metallographic techniques, and also by electrochemical corrosion measurements. The welding parameters and the preheating temperature greatly infuenced the weld shape and the austenite content in the weld metal. It was found that the focus point distance from the sheet surface had signifcant efect on the weld geometry. Changing the focus point distance to+2 mm, the penetration depth increased from 4.96 to 5.53 mm, and increased the austenite content by 2.6%. Due to the preheating the welds became wider and shallower, e.g., from 4.96 to 4.08 mm penetration depth, while the cross-section are increased from 5.10 to 6.12 mm2 at the same sample. The preheating resulted in more intergranular austenite formation, which meant maximum 4% increase in the weld metal. The increasing austenite content resulted in increasing pitting corrosion resistance in 3.5% NaCl electrolyte, the highest increase was 90 mV.

  • Efficiency of Artificial Intelligence Methods for Hearing Loss Type Classification: an Evaluation
    • Michał Kassjański
    • Marcin Kulawiak
    • Tomasz Przewoźny
    • Dmitry Tretiakow
    • Jagoda Kuryłowicz
    • Andrzej Molisz
    • Krzysztof Koźmiński
    • Aleksandra Kwaśniewska
    • Paulina Mierzwińska-Dolny
    • Miłosz Grono
    2024 Journal of Automation, Mobile Robotics and Intelligent Systems - JAMRIS

    The evaluation of hearing loss is primarily conducted by pure tone audiometry testing, which is often regarded as golden standard for assessing auditory function. If the presence of hearing loss is determined, it is possible to differentiate between three types of hearing loss: sensorineural, conductive, and mixed. This study presents a comprehensive comparison of a variety of AI classification models, performed on 4007 pure tone audiometry samples that have been labeled by professional audiologists in order to develop an automatic classifier of hearing loss type. The tested models include Logistic Regression, Support Vector Machines, Stochastic Gradient Descent, Decision Trees, Random Forest, Feedforward Neural Network (FNN), Convolutional Neural Network (CNN), Recurrent Neural Network (RNN), Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU). The presented work also investigates the influence of training dataset augmentation with the use of a Conditional Generative Adversarial Network on the performance of machine learning algorithms and examines the impact of various standardization procedures on the effectiveness of deep learning architectures. Overall, the highest classification performance, was achieved by LSTM with an out-of-training accuracy of 97.56%.

  • Efficient Analysis of Noise Induced in Low-Voltage Installations Placed Inside Buildings with Lightning Protection Systems
    • Artur Noga
    • Tomasz Topa
    • Tomasz Stefański
    2024 Electronics

    This paper describes an efficient approach to the broadband analysis of lightning protection systems (LPSs) using the method of moments (MoM) implemented in the frequency domain. The adaptive frequency sampling (AFS) algorithm, based on a rational interpolation of the relevant observable (e.g., voltage, current, electric or magnetic field) which describes the properties of the LPS, is employed to reduce the number of samples computed by the full-wave MoM. This improvement is achieved by the quick comparison of two interpolants with the use of the Stöer–Bulirsch algorithm, which provides the frequency location of the next MoM samples for computations. This algorithm allows for the efficient localization of resonant frequencies while reducing the number of samples computed over the entire frequency range. In the instances when the induced noise is determined in low-voltage installations protected by various types of LPSs, reductions in computational overhead equal to 47.9× and 72.1× in broadband LPS simulations are obtained. Hence, the proposed approach allows for a significant reduction in computational overhead in comparison to standard, uniformly sampled simulations.

  • Efficient Calibration of Cost-Efficient Particulate Matter Sensors Using Machine Learning and Time-Series Alignment
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Marek Wójcikowski
    • Bogdan Pankiewicz
    2024 KNOWLEDGE-BASED SYSTEMS

    Atmospheric particulate matter (PM) poses a significant threat to human health, infiltrating the lungs and brain and leading to severe issues such as heart and lung diseases, cancer, and premature death. The main sources of PM pollution are vehicular and industrial emissions, construction and agricultural activities, and natural phenomena such as wildfires. Research underscores the absence of a safe threshold for particulate exposure, highlighting the crucial need for monitoring PM levels to develop and implement effective risk mitigation measures. Notwithstanding, accurate measurement of PM concentration relies on expensive and cumbersome equipment. Despite the rising popularity of low-cost alternatives, their reliability remains questionable, given their sensitivity to environmental conditions, inherent instability, and manufacturing imperfections. This article proposes a novel approach to efficient correction of low-cost PM sensors. The primary calibration model is a feedforward artificial neural network (ANN), which directly renders predicted output of the corrected sensor based on environmental variables such as temperature, humidity, and atmospheric pressure. The ANN hyper-parameters are identified by aligning time series of prior reference and low-cost sensor readings, which enables the network to learn typical temporal changes of the sensor outcome as a function of the aforementioned parameters as well as operational relationships between the sensor and the reference device. The architecture of the ANN is optimized in terms of the number of neurons in each layer to enhance its generalization capability. Our methodology has been demonstrated using a custom-designed portable monitoring platform and reference data acquired from public stations in Gdansk. The results are indicative of excellent calibration reliability. The achieved correlation coefficients w.r.t. the reference readings are 0.86, 0.88, and 0.72 for PM1, PM10, and PM2.5, respectively, whereas RMSE values are only 3.0, 3.9, and 5.4 µg/m³.

  • Efficient method for octahedral NH2-MIL-125 (Ti) synthesis: Fast and mild conditions
    • Mateusz Baluk
    • Aleksandra Pieczyńska
    • Malwina Kroczewska
    • Justyna Łuczak
    • Krzysztof Matus
    • Kostiantyn Nikiforow
    • Adriana Zaleska-Medynska
    2024 CHEMICAL ENGINEERING JOURNAL

    A new hot injection method for preparing octahedral NH2-MIL-125 (Ti) was developed. This method is six times faster and conducted under milder conditions, i.e., at 120°C in a flask, and exhibits higher crystal formation efficiency than the commonly used solvothermal method while maintaining comparable structural, optical, and photocatalytic properties.

  • Efficient removal of 2,4,6-trinitrotoluene (TNT) from industrial/military wastewater using anodic oxidation on boron-doped diamond electrodes
    • Małgorzata Szopińska
    • Piotr Prasuła
    • Piotr Baran
    • Iwona Kaczmarzyk
    • Mattia Pierpaoli
    • Jakub Nawała
    • Mateusz Szala
    • Sylwia Fudala-Książek
    • Agata Kamieńska-Duda
    • Anna Dettlaff
    2024 Pełny tekst Scientific Reports

    With growing public concern about water quality particular focus should be placed on organic micropollutants, which are harmful to the environment and people. Hence, the objective of this research is to enhance the security and resilience of water resources by developing an efficient system for reclaiming industrial/military wastewater and protecting recipients from the toxic and cancerogenic explosive compound – 2,4,6-trinitrotoluene (TNT), which has been widely distributed in the environment. This research used an anodic oxidation (AO) process on a boron-doped diamond (BDD) electrode for the TNT removal from artificial and real-life matrices: marine water and treated wastewater. During experiments, TNT concentrations were significantly decreased, reaching the anodic degradation efficiency of above 92% within two hours and > 99.9% after six hours of environmental sample treatment. The presented results show the great potential of AO performed on BDD anodes for full-scale application in the industry and military sectors for TNT removal.

  • Efficient Simulation-Based Global Antenna Optimization Using Characteristic Point Method and Nature-Inspired Metaheuristics
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2024 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    Antenna structures are designed nowadays to fulfil rigorous demands, including multi-band operation, where the center frequencies need to be precisely allocated at the assumed targets while improving other features, such as impedance matching. Achieving this requires simultaneous optimization of antenna geometry parameters. When considering multimodal problems or if a reasonable initial design is not at hand, one needs to rely on global search. Yet, a reliable rendition of the system outputs necessitates the employment of electromagnetic (EM) analysis, associated with considerable CPU costs. Global optimization under such circumstances is extremely challenging. This especially applies to nature-inspired algorithms known for exceptionally poor computational efficiency. Whereas surrogate-assisted approach is of limited use due to difficulties related to a construction of reliable behavioral antenna models. Here, we suggest a novel methodology for efficient global optimization of multi-band antenna structures, where the surrogate is repeatedly built and refined using custom-defined response features. The infill criteria are based on minimizing surrogate-evaluated objective function, whereas the underlying optimization engine is the particle swarm optimization algorithm (PSO). Comprehensive benchmarking, demonstrates superiority of the presented approach over surrogate-assisted methods handing antenna frequency responses, as well as direct nature-inspired optimization.

  • Electrical Interface Parameters of PEDOT: PSS: Effect of Electrodeposition Charge Evaluated Under Body Conditions for Neural Electrode Applications
    • Mohammad Taghi Tourchi Moghadam
    • Karolina Cysewska
    2024 JOURNAL OF THE ELECTROCHEMICAL SOCIETY

    This study explores the influence of the deposition charge of poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonate (PEDOT:PSS) on its electrical interface parameters. For this purpose, PEDOT:PSS was fabricated by electrodeposition on commercial platinum electrodes with the time limited by different charges (1, 3, 6, 9 mC). Further, the electrodes were characterized regarding their electrical interface such as interfacial impedance, potential window, double-layer capacitance, charge storage capacity, and current injection limit under simulated body conditions. The work showed whether and to what extent the change of deposition charge affected the electrical interface parameters of PEDOT:PSS-based platinum electrodes. The electrodes polymerized with 9 mC exhibited a significant increase in specific capacitance, indicating enhanced charge storage capacity. Additionally, this sample demonstrated lower resistance in phosphate-buffered saline, suggesting improved conductivity.

  • Electrical properties of A-site Ca-doped LaNb1-xAsxO4-δ ceramics
    • Piotr Winiarz
    • Maria Gazda
    • Arkadiusz Dawczak
    • Sebastian Wachowski
    2024 SOLID STATE IONICS

    The electrical properties of A-site Ca-doped LaNbO4 with the addition of As in the B-site, have been investigated. Total, grain- and specific grain boundary electric conductivities in different oxygen partial pressure, and water vapour partial pressure were determined. Additional conductivity measurements were performed in nitrogen, to suppress the possible p-type conductivity, focusing on protonic conductivity. The maximum measured total conductivity was recorded for La0.99Ca0.01Nb0.9As0.1O4-δ at 800 °C, which was equal to 1.2·10−4 S·cm−1 in H2O- humidified air, and 2.2·10−5 S·cm−1 in H2O- humidified N2. From the deconvoluted data, the lowest activation energies for grain conduction were obtained in both atmospheres for La0.99Ca0.01Nb0.7As0.3O4-δ. In the temperature range 400 °C – 550 °C it was 0.23 eV and 0.13 eV respectively for H2O- humidified air and H2O- humidified N2. The results show that the increasing arsenic amount mainly influences the activation energies, whereas the calcium addition slightly improves the grain conductivity. The pO2 experiments revealed that in oxidizing atmospheres, electron holes contribute to the conductivity. The high proton transfer numbers were obtained for each sample, peaking at tH+ = 0.91 for LaNb0.7As0.3O4 at 400 °C. Interestingly, even at elevated temperatures relatively high values are obtained where tH+ = 0.87 was recorded at 800 °C for La0.99Ca0.01Nb0.9As0.1O4-δ.

  • Electrical Simulations of the SIS100 Superconducting Dipole and Quadrupole Circuits: Transients, Earthing and Failure Modes
    • Piotr Szwangruber
    • V. Raginel
    • D. Delkov
    • E. Ravaioli
    • V. Plyusnin
    • Michał Michna
    • Andrzej Wilk
    • Marek Wołoszyk
    • W. Freisleben
    • M. Dziewiecki
    • Michał Ziółko
    • C. Roux
    • Stanisław Galla
    2024 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY

    The 100 Tm superconducting synchrotron SIS100 is the main accelerator of the international Facility for Antiproton and Ion Research (FAIR) currently under advanced construction in Darmstadt, Germany. The SIS100 dipole circuit which creates the magnetic field required to bend the beam, consists of 108 dipoles distributed over six arc sections of the ring. The magnetic field for the beam focusing is generated by three individual quadrupole circuits with total amount of 166 magnets located in both arc and straight sections of the ring. The dipole circuit is powered from two synchronized power converters and will be cycled up to 13.2 kA at 28 kA/s. The dipole magnet chain is not self-protecting. 12 energy extraction resistors are used to protect the superconducting coils and bus-bars against overheating and overvoltage in case of a quench. The largest quadrupole circuit consists of 83 magnets. The nominal current is 10.5 kA cycled up to 22 kA/s. Similarly to dipoles, the quadrupole circuit is not self-protecting. Four energy extraction units are used to discharge the circuit's energy in case of a quench or fast power abort. This work presents a customized Python software tool created to simulate electrical behavior of a superconducting magnet chain. The software is under development at GSI. However, certain modules strongly rely on the approach developed at CERN. The paper contains selected simulations of the SIS100 dipole and defocusing quadrupole circuits. Special attention is drawn to: transient effects during typical operation and during the fast power abort; the damping effect of vacuum chambers; voltage distribution in the circuits and basic failure modes.

  • Electrochemical cobalt oxidation in chloride media
    • Iryna Makarava
    • Jere Vanska
    • Agnieszka Kramek
    • Jacek Ryl
    • Benjamin Paul Wilson
    • Kirsi Yliniemi
    • Mari Lundstron
    2024 Pełny tekst MINERALS ENGINEERING

    The green transition, despite recent advances in cobalt-free battery technologies, is still highly dependent on the availability of critical cobalt-based materials. Consequently, there has been increasing interest towards the development of new methods that maximize critical metals recovery from industrial hydrometallurgical solutions. In the current study, direct anodic oxidation of cobalt species from cobalt chloride solutions was studied as one alternative future strategy for cobalt recovery. Electrochemical methods were used (cyclic voltammetry, potentiostatic anodic deposition) and the effect of pH, temperature, and the concentration of cobalt and chloride ions on cobalt precipitation were investigated. The increase of pH and temperature was shown to stabilize the electrochemical oxidation of cobalt, while a decrease in cobalt concentration had a negative effect on precipitation. Scanning Electron Microscope, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy were exploited to evaluate the morphology, structure, and composition of obtained anodic product. Calculated for potentiostatic anodic deposition (at highest studied potential of 1300 mV vs. Ag/AgCl) nucleation mechanism shows that the rate of nucleation for oxygen-cobalt species is faster than the subsequent growth rate of nuclei (instantaneous mechanism). XPS results confirmed that mixed Co3O4/Co(OH)2/CoOOH precipitate could be obtained by optimized anodic potentiostatic deposition in the range from 900 to 1150 mV and pH from 3 to 6 at 60 °C.

  • Electrochemical detection of bacterial endotoxin lipopolysaccharide (LPS) on gold electrode modified with DAL-PEG-DK5-PEG-OH - Antimicrobial peptide conjugate
    • Kosikowska Paulina
    • Anna Golda
    • Jacek Ryl
    • Magdalena Pilarczyk-zurek
    • Grzegorz Bereta
    • Tadeusz Ossowski
    • Adam Lesner
    • Joanna Koziel
    • Adam Prahl
    • Paweł Niedziałkowski
    2024 TALANTA.The International Journal of Pure and Applied Analytical Chemistry

    This work describes fabrication of gold electrodes modified with peptide conjugate DAL-PEG-DK5-PEG-OH that enables ultra-sensitive detection of lipopolysaccharide (LPS) isolated from the reference strain of Escherichia coli O26:B6. The initial step of the established procedure implies immobilization of the fully protected DAL-PEG-DK5-PEG-OH peptide on the surface of the gold electrode previously modified by cysteamine. Then side chain- and Fmoc-deprotection was performed in situ on the electrode surface, followed by its incubation in 1 % of BSA solution to block non-specific bindings sites before LPS detection. The efficiency of the modification was confirmed by X-ray Photoelectron Spectroscopy (XPS) measurements. Additionally, the cyclic voltammetry (CV) and electrochemical impendance spectroscopy (EIS) were employed to monitor the effectiveness of each step of the modification. The obtained results confirmed that the presence of the surface-attached covalently bound peptide DAL-PEG-DK5-PEG-OH enables LPS detection by means of CV technique within the range from 5 × 10−13 to 5 × 10−4 g/mL in PBS solution. The established limit of detection (LOD) for EIS measurements was 4.93 × 10−21 g/mL with wide linear detection range from 5 × 10−21 to 5 × 10−14 g/mL in PBS solution. Furthermore, we confirmed the ability of the electrode to detect LPS in a complex biological samples, like mouse urine and human serum. The effectiveness of the electrodes in identifying LPS in both urine and serum matrices was confirmed for samples containing LPS at both 2.5 × 10−15 g/mL and 2.5 × 10−9 g/mL.

  • Electrochemical Oxidation of Selected Micropollutants from Environment Matrices Using Boron-Doped Diamond Electrodes: Process Efficiency and Transformation Product Detection
    • Filip Gamoń
    • Sebastian Żabczyński
    • Małgorzata Szopińska
    • Mattia Pierpaoli
    • Dawid Zych
    • Robert Bogdanowicz
    • Wojciech Artichowicz
    • Aneta Łuczkiewicz
    • Sylwia Fudala-Książek
    2024 Water

    Bisphenol A (BPA) and diclofenac (DCF) are among the most prevalent micropollutants in aquatic environments, with concentrations reaching up to several hundred μg/L. These compounds pose significant risks to biodiversity and environmental health, necessitating the development of effective removal methods. However, both BPA and DCF can be resistant to conventional treatment technologies, highlighting the need for innovative approaches. Electrochemical oxidation (EO) has emerged as a promising solution. In this study, we assessed the effectiveness of EO using borondoped diamond (BDD) anodes to remove BPA and DCF from two types of treated wastewater (TWW-W and TWW-D) and landfill leachate (LL). The evaluation included an analysis of the removal efficiency of BPA and DCF and the identification of transformation products generated during the process. Additionally, the feasibility of the EO-BDD process to remove ammonium nitrogen (N-NH4+) and organic compounds present in these environmental matrices was investigated. The EO-BDD treatment achieved remarkable removal efficiencies, reducing BPA and DCF concentrations by over 96% in LL and TWW-W. Transformation product analyses identified four intermediates formed from parent compounds during the oxidation process. Furthermore, the EO-BDD process effectively removed both chemical oxygen demand (COD) and ammonium nitrogen from LL, although weaker results were observed for TWWs. These findings underscore the potential of the EO-BDD process as an effective method for the removal of BPA and DCF from challenging matrices, such as wastewater containing micropollutants. It also shows promise as a complementary technology for enhancing current conventional wastewater treatment methods, especially biological degradation.

  • Electrode-based floating treatment wetlands: Insights into design operation factors influencing bioenergy generation and treatment performance
    • Ewa Wojciechowska
    • Joanna Strycharz
    • Nicole Nawrot
    • Sławomir Ciesielski
    • Przemysław Kowal
    • Krzysztof Czerwionka
    • Karolina Matej-Łukowicz
    2024 SCIENCE OF THE TOTAL ENVIRONMENT

    Exponential increases in energy consumption and wastewater have often irreversible environmental impacts. As a result, bio-electrochemical devices like microbial fuel cells (MFCs), which convert chemical energy in organic matter to electricity using exoelectrogenic bacteria, have gained interest. However, operational factors affecting efficiency and energy output need further study. This research investigated bioenergy production and COD, TN, and TP removal in mesoscale floating treatment wetlands (FTW-MFC) using Phragmites australis, Iris pseudacorus, and a mix of both. The Iris FTW-MFC achieved a high voltage peak of 2100 mV, with maximum power densities of 484 mW/m², 1196 mW/m², and 441 mW/m² for Phragmites, Iris, and mixed FTW-MFCs, respectively. Despite promising bioenergy yields, pollutant removal was unsatisfactory. A low area/height ratio (0.38 m²/0.8 m) and high loading rate (18.1 g/m²·d COD) boosted bioenergy output but hindered treatment performance and stressed plants, causing root decay. No significant pollutant removal differences were found between FTW-MFC and FTW. Higher relative plant growth rates occurred in the FTW-MFC. Microbial analysis shown that representatives of Pseudomonas and Clostridium species were consistently found across all samples, involved in both organic compound transformation and electricity generation, contributed to successful microscale results. A supporting microscale MFC experiment showed wastewater composition's impact on bioenergy yield and pollutant removal. Pre-inoculated reactors improved organic matter transformation and electricity generation, while aeration increased voltage and treatment performance. The role of plants requires further verification in future experiments.

  • Electrophoretic deposition and characterization of composite chitosan/Eudragit E 100 or poly(4-vinylpyridine)/mesoporous bioactive glass nanoparticles coatings on pre-treated titanium for implant applications
    • Łukasz Pawłowski
    • Muhammad Asim Akhtar
    • Andrzej Zieliński
    • Aldo R. Boccaccini
    2024 SURFACE & COATINGS TECHNOLOGY

    Titanium implants are surface-modified to achieve bioactivity and often antibacterial properties. Such surface coatings may increase corrosion degradation and be weakly attached to the substrate. In the present research, biodegradable composite coatings, investigated so far as smart environment-sensitive, slowly releasing silver to the implant neighborhood, were produced as a combination of chitosan (CS) with Eudragit E 100 (EE100) or poly(4-vinylpyridine) (P4VP) polymers incorporating mesoporous bioactive glass nanoparticles (MBGNs). Such coatings were designed to positively affect corrosion resistance, bioactivity in vitro, and the bonding to the surface. The coating was obtained in a single electrophoretic deposition (EPD) process on the surface of chemically etched grade 2 titanium. The deposition was carried out using an ethanol-based suspension for 5 min at 60 V. Suspension stability was assessed through the quantification of zeta potential. The fabricated coatings underwent microstructural analysis, chemical composition profiling, surface roughness measurement, wettability assessment, thickness determination, evaluation of corrosion resistance, and investigation of their adherence to metallic substrates. Additionally, an immersion test extending up to 14 days was employed to assess the coatings' capacity for calcium phosphate formation. The resulting coatings tightly covered the metallic substrate; the CS/EE100/MBGNs coating exhibited superior uniformity, which can be attributed to the increased stability of this suspension, indicated by a higher zeta potential value. The deposited MBGNs showed a diameter of <100 nm. The prepared coatings have contributed to improved corrosion resistance of the system and facilitated the deposition of calcium phosphates. All investigated surfaces showed hydrophilic properties. Substrate-coating adhesion was notably enhanced for the CS/EE100/MBGNs coating. The proposed coatings, after in vitro and in vivo cytotoxicity studies, can successfully be applied on long-term load-bearing titanium bone implants.

  • Elucidating charge transfer process and enhancing electrochemical performance of laser-induced graphene via surface engineering with sustainable hydrogel membranes: An electrochemist's perspective
    • Mohsen Khodadadiyazdi
    • Aiswarya Manohar
    • Adrian Olejnik
    • Agata Smułka
    • Agnieszka Kramek
    • Mattia Pierpaoli
    • Mohammed Saeb
    • Robert Bogdanowicz
    • Jacek Ryl
    2024 TALANTA.The International Journal of Pure and Applied Analytical Chemistry

    Laser-induced graphene (LIG) has emerged as a promising solvent-free strategy for producing highly porous, 3D graphene structures, particularly for electrochemical applications. However, the unique character of LIG and hydrogel membrane (HM) coated LIG requires accounting for the specific conditions of its charge transfer process. This study investigates electron transfer kinetics and the electroactive surface area of LIG electrodes, finding efficient kinetics for the [Fe(CN)6]3-/4- redox process, with a high rate constant of 4.89 x 10−3 cm/s. The impact of polysaccharide HM coatings (cationic chitosan, neutral agarose and anionic sodium alginate) on LIG's charge transfer behavior is elucidated, considering factors like ohmic drop across porous LIG and Coulombic interactions/permeability affecting diffusion coefficient (D), estimated from amperometry.It was found that D of redox species is lower for HM-coated LIGs, and is the lowest for chitosan HM. Chitosan coating results in increased capacitive share in the total current while does not apparently reduce Faradaic current. Experimental findings are supported by ab-initio calculations showing an electrostatic potential map's negative charge distribution upon chitosan chain protonation, having an effect in over a two-fold redox current increase upon switching the pH from 7.48 to 1.73. This feature is absent for other studied HMs. It was also revealed that the chitosan's band gap was reduced to 3.07 eV upon acetylation, due to the introduction of a new LUMO state. This study summarizes the operating conditions enhanced by HM presence, impacting redox process kinetics and presenting unique challenges for prospective LIG/HM systems' electrochemical applications.

  • Elucidating photoluminescent properties of Eu‐doped Ca–Al–Si–O(–N) glasses and the local structures of Eu ions
    • Hiroyo Segawa
    • Natalia Wójcik
    • Kohsei Takahashi
    • Takashi Takeda
    • Sharafat Ali
    2024 JOURNAL OF THE AMERICAN CERAMIC SOCIETY

    Europium (Eu) ion–doped luminescent materials have attracted considerable attention for their numerous optical applications. Eu-doped Ca–Al–Si–O(–N) glasses were synthesized from a mixture of oxynitride glasses and Eu2O3 powder using a standard melt-quenching technique in a radiofrequency furnace. The source Eu trivalent ions primarily changed to Eu2+ during melting, and the ratio of Eu2+ ions increased with an increase in Eu content in the starting mixture. All the prepared glasses exhibited photoluminescence (PL) owing to the 5d–4f transition of Eu2+ ions. The absorption edge and PL wavelength shifted to longer wavelength with an increase in Eu content. Moreover, oxynitride glasses exhibited a longer wavelength than those of oxide glasses. The internal quantum efficiency (IQE) increased with the increase in Eu content until it reached a maximum. X-ray absorption structure and electron spin resonance spectroscopies were used to determine the local structure of Eu ions, which confirmed that changes in the local structure of Eu ions were responsible for the shift in PL peak and the change in IQE. The development of the Eu-doped Ca–Al–Si–O–N glasses is highly inspiring for transparent phosphors.

  • Embracing silence: Creating inclusive spaces for autistic employees
    • Joanna Szulc
    2024 Pełny tekst Industrial and Organizational Psychology-Perspectives on Science and Practice

    I concur with Asselineau et al. (2024) that workplace silence profoundly impacts individual and organizational processes. Although they have detailed its significance across different contexts, a vital aspect merits deeper investigation. Namely, many autistic individuals exhibit hypersensitivity to sensory stimuli, such as noise. For this demographic, as well as for nonautistic individuals with sensory processing disorders, exposure to noise can be extremely distressing. In this commentary, I outline how Asselineau et al.’s ideas can be further applied in the context of autistic employees and those with sensory processing disorders to benefit both affected individuals and employers

  • Emerging contaminants and pathogenic microorganisms elimination in secondary effluent by graphitic carbon nitride photocatalytic ozonation processes
    • Eryk Fernandes
    • Paweł Mazierski
    • Magdalena Miodyńska
    • Tomasz Klimczuk
    • Adriana Zaleska-Medynska
    • Joana Oliveira
    • Ana Miguel Matos
    • Rui F. Martins
    • João Gomes
    2024 CATALYSIS TODAY

    The complexity of water contaminants, both chemical and biological requires an efficient and feasible treatment alternative. Herein, the photocatalytic ozonation treatment using graphitic carbon nitride catalysts was effectively applied for the elimination of a mixture of targeted chemical contaminants, and both Escherichia coli bacteria and Human polyomavirus JC (JC virus) in real secondary wastewater. The exfoliation treatment was compared in catalysts prepared using urea and melamine as precursors. The physical treatment provided no significant enhancement in the urea-based catalyst, while the improvement in the structure of the melaminebased (36MCN) material and formation of melem heterojunction increased its catalytic properties. In both sets of contaminants, the photocatalytic ozonation systems were superior to photolytic ozonation, especially regarding ozone consumption. The best catalyst, 36MCN, resulted in a decrease of 57.5%, 33.0% and 29.0% in the ozone dose required to eliminate chemical, bacteria and virus contaminants, respectively. The hydroxyl radicals were also shown as a key responsible for the pollutant’s elimination. The higher radical production and decomposition of ozone are possible indications of the better performance of graphitic carbon nitride photocatalytic ozonation, as an efficient tertiary wastewater alternative.

  • Emission and properties of airborne wear particles from train brake friction materials based on novolac phenolic resins and butadiene rubbers
    • Yurii Tsybrii
    • Oleksii Nosko
    • Izabela Zglobicka
    • Michal Kuciej
    2024 Pełny tekst WEAR

    The emission of airborne particulate matter from a train brake depends on the formulation of its friction material. This study investigates the emission and properties of wear particles from train brake friction materials based on straight or resorcinol-modified novolac phenolic resin and nitrile or styrene butadiene rubber used as binding ingredients. The wear particles are generated by a pin-on-disc tribomachine inside an aerodynamic chamber, counted and collected using aerosol measurement techniques, subjected to microscopic and elemental analysis. It has been found that the modification of novolac phenolic resin with resorcinol has no considerable effects on the emission of wear particles and their properties. By contrast, replacing styrene butadiene rubber with nitrile butadiene rubber leads to a significant decrease in the emission of 0.1–10 μm wear particles.