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  • Effect of lag screw on stability of first metatarsophalangeal joint arthrodesis with medial plate
    • Karol Daszkiewicz
    • Magdalena Rucka
    • Krzysztof Czuraj
    • Angela Andrzejewska
    • Piotr Łuczkiewicz
    2024 PeerJ

    Background: First metatarsophalangeal joint (MTP-1) arthrodesis is a commonly performed procedure in the treatment of disorders of the great toe. Since the incidence of revision after MTP-1 joint arthrodesis is not insignificant, a medial approach with a medially positioned locking plate has been proposed as a new technique. The aim of the study was to investigate the effect of the application of a lag screw on the stability and strength of first metatarsophalangeal joint arthrodesis with medial plate. Methods: The bending tests in a testing machine were performed for models of the first metatarsal bone and the proximal phalanx printed on a 3D printer from polylactide material. The bones were joined using the locking titanium plate and six locking screws. The specimens were divided into three groups of seven each: medial plate and no lag screw, medial plate with a lag screw, dorsal plate with a lag screw. The tests were carried out quasi-static until the samples failure. Results: The addition of the lag screw to the medial plate significantly increased flexural stiffness (41.45 N/mm vs 23.84 N/mm, p = 0.002), which was lower than that of the dorsal plate with a lag screw (81.29 N/mm, p < 0.001). The similar maximum force greater than 700 N (p > 0.50) and the relative bone displacements lower than 0.5 mm for a force of 50 N were obtained for all fixation techniques. Conclusions: The lag screw significantly increased the shear stiffness in particular and reduced relative transverse displacements to the level that should not delay the healing process for the full load of the MTP-1 joint arthrodesis with the medial plate. It is recommended to use the locking screws with a larger cross-sectional area of the head to minimize rotation of the medial plate relative to the metatarsal bone.

  • Effect of multi-walled carbon nanotubes properties on the photocatalytic activity of bismuth-based composites synthesised via an imidazolium ionic liquid
    • Aleksandra Bielicka-giełdoń
    • Patrycja Wilczewska
    • Monika Paszkiewicz
    • Anna Malankowska
    • Karol Szczodrowski
    • Jacek Ryl
    • Ewa Siedlecka
    2024 Pełny tekst APPLIED SURFACE SCIENCE

    The use of various types of multi-walled carbon nanotubes in the synthesis of bismuth oxybromide semiconductors via imidazolium ionic liquid was studied in detail. The effect of the MWCNT shape, specific surface area, and various diameters on the morphology, surface properties and photoactivity of the Bi-based composites has been investigated for the first time. So far, the literature has only shown the enhancement of photocatalytic activity of composites containing MWCNT; however, our research shows a broader view of the issue. The photocatalytic activity of the individual composites under UV–Vis irradiation was assessed by the degradation of various micropollutants, showing the diversity of properties of the obtained composites. It is also significant that in the composite system, the imidazolium ionic liquid played a crucial role in the formation of microspheres and acted as a dispersing agent, leading to an even distribution of MWCNTs on the surface of the spherical bismuth oxybromide.

  • Effect of strain level on the stiffness of cold recycled bituminous mixtures
    • Vittoria Grilli
    • Andrea Grilli
    • Andrea Graziani
    • Mariusz Jaczewski
    2024

    Cold recycling is a sustainable technology for the rehabilitation of bitumi-nous pavements. This study investigates the stiffness response of cement-bitumen treated materials (CBTM)manufactured with 80% reclaimed asphalt and treated with 2.0% Portland cement and 4.0% bitumen emulsion. Indirect tensile stiffness modulus tests were carried out to assess the strain dependence of stiffness at target horizontal deformation levels between 2 and 15 micrometers. Ultrasonic pulse velocity was also measured to evaluate stiffness at very low strain level. The tests were carried out at three temperatures (5, 20, 35C) on CBTMspecimens with 14 % of voids. The results showed that the CBTM stiffness decreased with increasing deformation level. Small-strain results can be used to estimate the linear viscoelastic response whereas damage can be observed when the deformation level is increased

  • Effect of the ex situ physical and in situ chemical modification of bacterial nanocellulose on mechanical properties in the context of its potential applications in heart valve design
    • Alicja Stanisławska
    • Marek Szkodo
    • Hanna Staroszczyk
    • Kinga Dawidowska
    • Magdalena Kołaczkowska
    • Piotr Siondalski
    2024 Pełny tekst INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

    Bacterial nanocellulose (BNC) is a promising material for heart valve prostheses. However, its low strength properties limit its applicability in cardiovascular surgery. To overcome these limitations, the mechanical properties of BNC can be improved through modifications. The aim of the research was to investigate the extent to which the mechanical properties of BNC can be altered by modifying its structure during its production and after synthesis. The study presents the results of various analyses, including tensile tests, nanoindentation tests, X-ray diffraction (XRD) tests, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy, conducted on BNC chemically modified in situ with hyaluronic acid (BNC/HA) and physically modified ex situ through a dehydration/rehydration process (BNC 25DR, BNC105DR, BNC FDR and BNC/HA 25DR, BNC/HA 105DR, BNC/HA FDR). The results demonstrate that both chemical and physical modifications can effectively shape the mechanical properties of BNC. These modifications induce changes in the crystalline structure, pore size and distribution, and residual stresses of BNC. Results show the effect of the crystalline structure of BNC on its mechanical properties. There is correlation between hardness and Young’s modulus and Iα/Iβ index for BNC/HA and between creep rate of BNC/HA, and Young’s modulus for BNC vs Iα/Iβ index.

  • Effect of Vascular Lumen Reduction on the Performance and Energy Consumption of an Innovative Implantable LVAD
    • Ryszard Jasiński
    • Krzysztof Tesch
    • Leszek Dąbrowski
    • Jan Rogowski
    2024 Pełny tekst Applied Sciences-Basel

    This paper presents the results of a study on the effect of vascular lumen reduction on the performance of an innovative implantable LVAD (left ventricular assist device). It details the pressures in the individual cardiac chambers as a function of device frequency. In addition, mass flow rates and energy consumption of the device are examined, varying with lumen reduction and operating frequency. While the lumen reduction of the vessels has little effect on energy consumption, the mass flow rates vary considerably, i.e., above 140 cyc/min, the mass flow rate increment is no longer achieved for specified initial conditions. There are also differences regarding the pressures in the heart; namely, it was found that the pressure plots look similar in all cases, leading to the conclusion that the reduction of the vessel lumen does not affect their shape, but does affect the maximum values of the left ventricular and aortic pressures. Importantly, the innovative device in the form of an intra-cardiac balloon assembly for circulatory support is based on a pulsatile flow strategy and is synchronized with the ECG signal. Other advantages of the proposed solution include a minimally invasive method of implantation, which is important for patients with end-stage heart failure. The design of the device is portable and the device itself is battery-powered, allowing for shorter hospitalization times and faster recovery, even in patients with end-stage heart failure associated with mitral regurgitation and pulmonary hypertension.

  • Effective sonophotocatalytic degradation of tetracycline in water: Optimization, kinetic modeling, and degradation pathways
    • Ansaf Karim
    • Grzegorz Boczkaj
    • Amritanshu Shriwastav
    2024 CHEMICAL ENGINEERING AND PROCESSING

    Hybrid advanced oxidation processes (AOPs) are gaining interest in degradation of variety of recalcitrant compounds for water and wastewater treatment, due to possible synergistic effects. The present study systematically evaluated the degradation of tetracycline (TC) with a sonophotocatalytic process combining acoustic cavitation (sonocavitation) and photocatalysis based on N-doped TiO2 catalyst. The TC degradation rate constant was 2.4 × 10−2 min−1, i.e., much higher than individual sonocatalytic (0.5 × 10−2 min−1) and photocatalysis (0.6 × 10−2 min−1) processes at the optimized conditions. The synergy index was 2.14, which reveals a significant improvement in the process performance. Maximum TC degradations of 55.5 ± 1.8 % for photocatalysis, 66.4 ± 1.8 % for sonocatalysis, and 79.5 ± 0.3 % for sonophotocatalysis were observed for 10 mg L−1 initial TC concentration after 90 min of treatment. The photocatalytic experiments were extended further to 210 min to achieve a maximum degradation of 78.9 ± 0.2 % at the optimized condition. Scavenging experiments confirmed that hydroxyl radicals (•OH), electron holes (h+), and superoxide radical anions (O2−•) played a significant role in the degradation of TC. Further, the degradation intermediates for each process were identified and degradation pathways were proposed. Empirical kinetic models based on operational parameters were also developed and validated.

  • 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 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 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.

  • 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 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