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Finite Element Analysis of Occupant Risk in Vehicular Impacts into Cluster Mailboxes
- Emre Palta
- Łukasz Pachocki
- Dawid Bruski
- Qian Wang
- Christopher Jaus
- Howie Fang
2025 Pełny tekst Computation
The deployment of cluster mailboxes (CMs) in the U.S. has raised safety concerns for passengers in potential vehicular crashes involving CMs. This study investigated the crashworthiness of two types of CMs through nonlinear finite element simulations. Two configurations of CM arrangements were considered: a single- and a dual-unit setup. These CM designs were tested on flat-road conditions with and without a curb. A 2010 Toyota Yaris and a 2006 Ford F250, both in compliance with the Manual for Assessing Safety Hardware (MASH), were employed in the analysis. The simulations incorporated airbag models, seatbelt restraint systems, and a Hybrid III 50th percentile adult male dummy. The investigations focused on evaluating the safety of vehicle occupants in 32 impact scenarios and under MASH Test Level 1 conditions (with an impact speed of 50 km/h). The simulation results provided insights into occupant risk and determined the primary failure mode of the CMs. No components of the mailboxes were found intruding into the vehicle’s occupant compartment. For all considered cases, the safety factors remained within allowable limits, indicating only a marginal risk of potential injury to occupants posed by the considered CMs.
Follow-up assessment of the microvascular function in patients with long COVID
- Marzena Romanowska-Kocejko
- Alicja Braczko
- Agata Jędrzejewska
- Marta Żarczyńska-Buchowiecka
- Tomasz Kocejko
- Barbara Kutryb-zając
- Marcin Hellmann
2025 MICROVASCULAR RESEARCH
Long COVID is a complex pathophysiological condition. However, accumulating data suggests that COVID-19 is a systemic microvascular endothelial dysfunction with different clinical manifestations. In this study, a microvascular function was assessed in long COVID patients (n = 33) and healthy controls (n = 30) using flow-mediated skin fluorescence technique (FMSF), based on measurements of nicotinamide adenine dinucleotide fluorescence intensity during brachial artery occlusion (ischemic response, IR) and immediately after occlusion (hyperemic response, HR). Microcirculatory function readings were taken twice, 3 months apart. In addition, we quantified biochemical markers such as the serum L-arginine derivatives and hypoxia-inducible factor 1α (HIF1α) to assess their relation with microvascular parameters evaluated in vivo. In patients with long COVID, serum HIF1α was significantly correlated to IRindex (r = −0.375, p < 0.05). Similarly, there was a significant inverse correlation of serum asymmetric dimethyl-L-arginine levels to both HRmax (r = −0.343, p < 0.05) and HRindex (r = −0.335, p < 0.05). The IR parameters were found lower or negative in long COVID patients and recovered in three-month follow-up. Hypoxia sensitivity value was significantly higher in long COVID patients examined after three months of treatment based on the combination of ACE-inhibitors and beta-adrenolytic compared to baseline condition (85.2 ± 73.8 vs. 39.9 ± 51.7 respectively, p = 0.009). This study provides evidence that FMSF is a sensitive, non-invasive technique to track changes in microvascular function that was impaired in long COVID and recovered after 3 months, especially in patients receiving a cardioprotective therapy.
Forward-Based DC-DC Converter With Eliminated Leakage Inductance Problem
- Oleksandr Matiushkin
- Oleksandr Husev
- Hossein Afshari
- Enrique Romero-Cadaval
- Carlos Roncero-Clemente
2025 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
The novel forward-based converter for low-power solar applications is presented in this work. The proposed converter provides an efficient performance in a wide range of the input voltage with low component count. The proposed dc-dc topologies are advanced forward dc-dc converters with an additional clamped output capacitor. The idea of such a type of converter is to transfer magnetizing energy of transformer to the output side, instead of using an input clamp circuit. Two possible topologies are considered to cover this feature. The design guidelines of the passive component of the proposed solutions are discussed. The converter may work in continuous conduction mode and discontinuous conduction mode due to different levels of the input power. A comparison between proposed topologies is made and discussed. Experimental prototype of the proposed forward-based dc-dc converter along with experimental results of the dc grid connection system are presented. The parameters of commercial photovoltaic panels have been chosen to validate the maximum power point tracking based on Perturb and Observe algorithm. The efficiency of the proposed solution is studied and discussed.
Genetic Determinants and Biofilm Properties Useful in Estimation of UTI Pathogenicity of the Escherichia coli Strains Isolated from Free-Living Birds
- Bartosz Rybak
- Tomasz Jarzembowski
- Agnieszka Daca
- Beata Krawczyk
- Lidia Piechowicz
2025 Antibiotics-Basel
Background/Objectives: According to the One Health concept, wild birds can be indicators of ecosystem pollution and disease incidence. Escherichia coli strains are widespread worldwide, but there are still few reports on the association of human infections with a potential reservoir of highly pathogenic human strains in wild birds. Fecal E. coli with uropathogenic potential (UPEC) can be transmitted between birds and humans and may be a risk factor for urinary tract infections (UTIs). Results: The results showed that above 50% of the isolates were grouped as highly pathogenic, according to Clermont phylogroup classification. Such strains were found to be stronger biofilm producers, with a higher adherence of monocytes than low pathogenic. However, the highest cytotoxicity was observed for strains described as aquatic environmental. Convergence of the results of the analysis of monocyte activation by E. coli strains and the ability to form biofilm by individual phylogroups of the strains tested was demonstrated. Genetic determinants of the uropathogenicity of E. coli (UPEC) correlate with the evidence of strain pathogenicity during monocyte activation in in vitro assays. Methods: In this study, we assessed the virulence potential of environmental strains isolated from wild waterfowl using genetic analysis (Clermont phylogroup classification) and phenotypic methods, including analysis of the human monocyte response to biofilm formation. The estimation of the ability to form biofilms was tested using crystal violet, and the pathogenic potential of strains by monocyte activation assay including changes in morphology, adhesion and cytotoxicity. Conclusions: In conclusion, the virulence of E. coli strains isolated from free-living birds is significant, and they can be considered environmental reservoirs of pathogenic strains. According to our observations, they can be responsible for the dissemination of uropathogenic strains among humans.
Gold(III) complexes with chloride and cyanopyridines: Facilitated hydrolysis of nitrile ligand to amide and antibacterial activity
- Maciej Ejnik
- Piotr Bruździak
- Karolina Gutmańska
- Anna Ciborska
- Magdalena Malik
- Dietrich Gudat
- Anna Brillowska-Dąbrowska
- Anna Dołęga
2025 SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
A range of novel simple gold(III) compounds has been synthesized in their monocrystalline form, including two previously unknown chloro-complexes of Au3+ with 2-cyanopyridine or 3-cyanopyridine, respectively. Our investigations have revealed the intricate nature of the reaction between 2-cyanopyridine and tetrachloroauric acid, yielding at least three distinct products. The main product, obtained in high yield, is a salt featuring a tetrachloroauric anion and a pyridinium cation stabilized by a hydrogen bond to a further 2-cyanopyridine molecule. Moreover, we observed the in-situ formation of a 2-cyanopyridine-AuCl3 complex, which undergoes hydrolysis of the nitrile bond to yield a picolinamide-Au(III) complex. The complexes were characterized by IR and Raman spectroscopies, NMR spectroscopy, and single-crystal XRD studies. Additional computational studies were conducted to explain unusual spectral features, the observed disparities in the complexation reactions of the three isomeric cyanopyridine ligands and the distinct reactivity of the complex with 2-cyanopyridine. Based on these studies, we propose a mechanism for the catalyzed hydrolysis of the nitrile bond within the Au(III) complex. Finally, we assessed the antimicrobial efficacy of the synthesized gold(III) complexes against a spectrum of bacteria and fungi.
Grey wolf optimizer integrated within boosting algorithm: Application in mechanical properties prediction of ultra high-performance concrete including carbon nanotubes
- A. Ӧzyüksel Çiftçioğlu
- Farzin Kazemi
- Torkan Shafighfard
2025 Applied Materials Today
Nowadays, the construction industry has increasingly recognized the superior performance characteristics of ultra high-performance concrete (UHPC). Known for its exceptional durability and high tensile strength, UHPC material is revolutionizing structure standards subjected to extreme environmental conditions and heavy loads. This paper explores the enhancement of UHPC with nano- and micromaterials, employing advanced machine-learning (ML) techniques to optimize the prediction of mechanical properties. Moreover, by introducing the novel extreme gradient boosting (XGBoost) improved by grey wolf optimizer (GWO) algorithm, this research represents the first integration of ML with GWO in UHPC research, significantly enhancing the accuracy of predictions for key properties such as compressive, tensile, and flexural strengths. The study investigates the impact of nanotechnology on UHPC, specifically how carbon nanotubes (CNTs) and microscale reinforcements contribute to advances in strength, durability, and resilience. These enhancements are pivotal in addressing limitations of traditional concrete, especially in high-demand construction environments. The proposed GWO-XGB model has demonstrated a remarkable ability to achieve R2 values of 98.4% and 94.8% for UHPC with nanomaterial and micromaterial, respectively, indicating very high level of accuracy in predicting mechanical properties. This model also had one of the lowest error values, demonstrating its precision and ability to minimize prediction errors. This approach significantly facilitates the testing and development of UHPC by automating the accurate determination of its mechanical properties, thereby reducing the reliance on costly and time-consuming experimental methods. Highlighting the transformative potential of combining ML with engineering science, this study offers promising avenues for innovations in construction practices.
Guided ultrasonic wave technique for corrosion monitoring and thickness variability analysis
- Beata Zima
2025 MEASUREMENT
Corrosion degradation poses a significant challenge to the structural integrity of industrial components, especially in critical sectors such as oil and gas, marine, and energy. This paper presents a novel approach to assessing corrosion damage using guided ultrasonic waves (GUWs), focusing on the statistical characterization of thickness variability in corroded plates. A combined algorithm is developed to estimate key statistical parameters, such as mean thickness and standard deviation, which describe the geometry of plates affected by corrosion. The study integrates theoretical analysis, experimental tests, and numerical simulations using Abaqus/Explicit to model plates with irregular thickness, employing random field methods to simulate surface roughness caused by corrosion. Experimental validation was conducted on steel plates subjected to accelerated corrosion tests, and guided waves were used to evaluate thickness variations along different propagation paths. The results demonstrate the accuracy of the proposed method in estimating the key geometrical parameters of corroded plates, even in the presence of complex surface degradation. This approach offers a significant improvement in the non-destructive testing of structural elements and can be an alternative to standard ultrasonic gauge measurement.
High performance ozone nanobubbles based advanced oxidation processes (AOPs) for degradation of organic pollutants under high pollutant loading
- Priya Koundle
- Neelkanth Nirmalkar
- Grzegorz Boczkaj
2025 JOURNAL OF ENVIRONMENTAL MANAGEMENT
Advanced Oxidation Processes (AOPs) have proven to be an effective solution for chemical wastewater treatment, particularly for degradation of organic pollutants, especially dyes. Ozonation is recognized as one of the most prevalent AOPs. Nevertheless, some cases show a lowered efficiency of O3 utilization which is attributed to its inadequate distribution in the treated water causing low residence time, low mass transfer coefficient as well as shorter half-life. This study demonstrates the application of ozone nanobubbles to enhance the degradation of organics under high pollution load conditions. We propose an integrated method that utilizes bulk nanobubbles to enhance the reactivity of ozone for the degradation of organics. We examined the degradation of organic pollutants under parameters such as varying pH levels, ozone concentrations and presence of salts and surfactants. The degradation of the organic pollutant by ozone nanobubbles (0.177 L mg−1min−1) demonstrated a threefold increase in reaction rate constants compared to microbubbles (0.025 L mg−1min−1). The plausible reason for these findings is (i) higher mass transfer coefficient (ii) higher ozone solubility (iii) NBs may act as a surface for chemical reaction (iv) NBs may increase the half-life of ozone. The presence of reactive oxygen species was verified using scavenging tests. This part of the studies revealed contribution of reactive oxygen species (ROSs) such as hydroxyl radical (•OH), superoxide radical anion (O2•-) and singlet oxygen (1O2) in the degradation process. The conditions that provide total degradation of 100% in 300 s for both organic pollutants (Green rit and methylene blue dye) are: 5 LPM (Litre per minute) ozone flow rate, acidic pH, monovalent salts (NaCl, 2 mM) and lower concentration of surfactants (CTAB and SDS, 0.3 CMC). A degradation mechanism has been outlined based on intermediates identified by LC-MS. This work presents a new method that combines AOPs with nanobubbles, which should lead to increased environmental sustainability and efficiency.
Higher‐Order Gravity Waves and Traveling Ionospheric Disturbances From the Polar Vortex Jet on 11–15 January 2016: Modeling With HIAMCM‐SAMI3 and Comparison With Observations in the Thermosphere and Ionosphere
- Sharon L. Vadas
- David R. Themens
- Joseph D. Huba
- Erich Becker
- Katrina Bossert
- Larisa Goncharenko
- Sophie J. Maguire
- Cosme A. O. B. Figueiredo
- Shuang Xu
- V. Lynn Harvey
- Nathaniel A. Frissell
- Michael J. Molzen
- Thomas J. Pisano
- Grzegorz Nykiel
2025 JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
In Vadas et al. (2024, https://doi.org/10.1029/2024ja032521), we modeled the atmospheric gravity waves (GWs) during 11–14 January 2016 using the HIAMCM, and found that the polar vortex jet generates medium to large-scale, higher-order GWs in the thermosphere. In this paper, we model the traveling ionospheric disturbances (TIDs) generated by these GWs using the HIAMCM-SAMI3 and compare with ionospheric observations from ground-based Global Navigation Satellite System (GNSS) receivers, Incoherent Scatter Radars (ISR) and the Super Dual Auroral Radar Network (SuperDARN). We find that medium to large-scale TIDs are generated worldwide by the higher-order GWs from this event. Many of the TIDs over Europe and Asia have concentric ring/arc-like structure, and most of those over North/South America have planar wave structure and occur during the daytime. Those over North/South America propagate southward and are generated by higher-order GWs from Europe/Asia which propagate over the Arctic. These latter TIDs can be misidentified as arising from geomagnetic forcing. We find that the higher-order GWs that propagate to Africa and Brazil from Europe may aid in the formation of equatorial plasma bubbles (EPBs) there. We find that the simulated GWs, TIDs and EPBs agree with EISCAT, PFISR, GNSS, and SuperDARN measurements. We find that the higher-order GWs are concentrated at 60 - 90 degrees N at z>= 200 km, in agreement with GOCE and CHAMP data. Thus the polar vortex jet is important for generating TIDs in the northern winter ionosphere via multi-step vertical coupling through GWs.
How IT Professionals Perceive Artificial Intelligence Myths
- Inés López-Baldominos
- Vera Pospelova
- Ana Castillo-Martínez
- Luis Fernández-Sanz
- Aleksandra Revina
- Nina Rizun
2025 Acta Polytechnica Hungarica
Artificial Intelligence (AI) has been recently attracting a lot of attention despite its long history. A good part of its presence in media and non-technical conversations is linked to existing myths and fears about its effects on humans and society. Literature has already analyzed how this type of information influences the general public and non-technical professionals but not how IT professionals react to AI myths. This article shows the results of a survey to a wide and varied sample of European IT professionals offering first insights on their perception of AI myths
Impact of free water on strain rate response of concrete in compression with a fully coupled DEM/CFD approach
- Marek Krzaczek
- Andrzej Tejchman-Konarzewski
- Michał Nitka
2025 Computational Particle Mechanics
W tym artykule zbadano wpływ zawartości wody na dynamiczne zachowanie betonu w stanie jednokierunkowego ściskania w mezoskali. Przeprowadzono obszerne dwuwymiarowe (2D) badania dynamiczne wpływu wolnej wody na dynamiczną wytrzymałość i pękanie betonu o niskiej porowatości. Dogłębnie zbadano wpływ szybkości odkształcania, nasycenia płynem i lepkości płynu. Zachowanie betonu w pełni i częściowo nasyconego płynem symulowano przy użyciu mezoskopowego modelu hydromechanicznego w skali porów opartego na unikalnym, w pełni sprzężonym podejściu DEM-CFD. Aby wygenerować ruch płynu, model zawierał sieć kanałów w ciągłym obszarze między dyskretnymi elementami. W częściowo mokrym betonie zaproponowano dwufazowy laminarny przepływ płynu (powietrza i wody) w porach i rysach. Aby dokładnie śledzić zawartość cieczy/gazu, uwzględniono położenie i objętość porów i rys. Na próbkach uproszczonej sferycznej mezostruktury, która imitowała beton zarówno w warunkach suchych, jak i mokrych, przeprowadzono szereg dynamicznych symulacji numerycznych z różnymi szybkościami odkształceń. Fragmentacja cząstek została pominięta. Dynamiczna wytrzymałość na ściskanie wzrastała wraz ze szybkością odkształceń, nasyceniem płynu i lepkością płynu. Ciśnienie płynu w porach spowalniało proces pękania z powodu zamknięcia płynu w porach, co skutkowało zwiększoną wytrzymałością betonu.
Impact of postharvest processing on the health benefits of durian-derived products
- Pitipong Thobunluepop
- Dejian Huang
- Alma Leticia Martinez-Ayala
- Emilia Ramos
- Rosario Maribel Robles-sánchez
- Martyna Lubinska-Szczygeł
- Rajamohamed Beema Shafreen
- Adamo Rombolà Domenico
- Aviva Ezra
- Emmanuelle Merquiol
- Svetlana Glikin
- Shela Gorinstein
2025 FOOD CHEMISTRY
Durian (Durio zibethinus Murr.) is a seasonal fruit with a short harvesting period, requiring postharvest processing such as cutting, peeling, freeze-drying, cooking, and frying to enhance its shelf life and nutritional quality. In this study, fresh Monthong durian (MTD), MTD Sticks, MTD Cake, and MTD Chips were analyzed for polyphenols, phenolic acids, tannins, flavonoids and thermal stability. Antioxidant activity was assessed using Cupric Reducing Antioxidant Capacity and DPPH radical scavenger methods. Fourier transform infrared spectra characterized the functional groups in extracts, while protein stability was evaluated by electrophoresis. Polyphenols' interaction with human serum proteins showed varied binding affinities, influenced by glycation, particularly in diabetic conditions. MTD had the highest phenolic content, followed by MTD Sticks, Cake, and Chips. This study proposes that durian products, abundant in polyphenols and produced without added sugar during postharvest processing, could serve as functional foods, potentially supporting the management of glycation-related disorders such as diabetes.
Implementation of Time-Averaged Restraints with UNRES Coarse-Grained Model of Polypeptide Chains
- Nguyen Truong Co
- Cezary Czaplewski
- Emilia Lubecka
- Adam Liwo
2025 Journal of Chemical Theory and Computation
Time-averaged restraints from nuclear magnetic resonance (NMR) measurements have been implemented in the UNRES coarse-grained model of polypeptide chains in order to develop a tool for data-assisted modeling of the conformational ensembles of multistate proteins, intrinsically disordered proteins (IDPs) and proteins with intrinsically disordered regions (IDRs), many of which are essential in cell biology. A numerically stable variant of molecular dynamics with time-averaged restraints has been introduced, in which the total energy is conserved in sections of a trajectory in microcanonical runs, the bath temperature is maintained in canonical runs, and the time-average-restraint-force components are scaled up with the length of the memory window so that the restraints affect the simulated structures. The new approach restores the conformational ensembles used to generate ensemble-averaged distances, as demonstrated with synthetic restraints. The approach results in a better fitting of the ensemble- averaged interproton distances to those determined experimentally for multistate proteins and proteins with intrinsically disordered regions, which puts it at an advantage over all-atom approaches with regard to the determination of the conformational ensembles of proteins with diffuse structures, owing to a faster and more robust conformational search.
Implementing an Analytical Model to Elucidate the Impacts of Nanostructure Size and Topology of Morphologically Diverse Zinc Oxide on Gas Sensing
- Sanju Gupta
- Haiyang Zou
2025 Pełny tekst Chemosensors
The development of state-of-the-art gas sensors based on metal oxide semiconductors (MOS) to monitor hazardous and greenhouse gas (e.g., methane, CH4, and carbon dioxide, CO2) has been significantly advanced. Moreover, the morphological and topographical structures of MOSs have significantly influenced the gas sensors by means of surface catalytic activities. This work examines the impact of morphological and topological networked assembly of zinc oxide (ZnO) nanostructures, including microparticles and nanoparticles (0D), nanowires and nanorods (1D), nanodisks (2D), and hierarchical networks of tetrapods (3D). Gas sensors consisting of vertically aligned ZnO nanorods (ZnO–NR) and topologically interconnected tetrapods (T–ZnO) of varying diameter and arm thickness synthesized using aqueous phase deposition and flame transport method on interdigitated Pt electrodes are evaluated for methane detection. Smaller-diameter nanorods and tetrapod arms (nanowire-like), having higher surface-to-volume ratios with reasonable porosity, exhibit improved sensing behavior. Interestingly, when the nanorods’ diameter and interconnected tetrapod arm thickness were comparable to the width of the depletion layer, a significant increase in sensitivity (from 2 to 30) and reduction in response/recovery time (from 58 s to 5.9 s) resulted, ascribed to rapid desorption of analyte species. Additionally, nanoparticles surface-catalyzed with Pd (~50 nm) accelerated gas sensing and lowered operating temperature (from 200 ◦C to 50 ◦C) when combined with UV photoactivation. We modeled the experimental findings using a modified general formula for ZnO methane sensors derived from the catalytic chemical reaction between methane molecules and oxygen ions and considered the structural surface-to-volume ratios (S/V) and electronic depletion region width (Ld) applicable to other gas sensors (e.g., SnO2, TiO2, MoO3, and WO3). Finally, the effects of UV light excitation reducing detection temperature help to break through the bottleneck of ZnO-based materials as energy-saving chemiresistors and promote applications relevant to environmental and industrial harmful gas detection.
Investigating the suitability of the matched fiber Bragg grating approach for guided wave based structural health monitoring
- Rohan Soman
- Farzam Omidi Moaf
- Piotr Fiborek
- Pawel Kudela
- Marzena Kurpińska
2025 MEASUREMENT
Fiber Bragg grating (FBG) sensors are thought to be ideal sensors for structural health monitoring (SHM). Amplitude based techniques such as matched filters and the edge-filtering have been proposed to fulfill the high sampling rates necessary for guided waves (GW) sensing. The current research for the first time shows the inherent robustness the matched filter technique provides to the sensing system. The matched system is realized through a FBG deployed on a low cost micrometer screw gauge which allows flexibility in matching the reflected wavelengths of the FBGs. Based on the results it is shown that, in the remote configuration the matched FBG approach is robust under changing temperature conditions. This concept has been shown analytically and experimentally. Furthermore, the approach is then extended for multiplexing of the sensors and the deployed system is used for detecting and localizing damage in the plate.
Investigation of structural, thermal, and electrical properties of sodium-doped oxynitride glass-ceramics
- Natalia Wójcik
- Abbas Saeed Hakeem
- Zuzanna Mielke
- Sharafat Ali
2025 MATERIALS CHEMISTRY AND PHYSICS
This study aimed to investigate the influence of Na2O addition on the structural, thermal, and electrical characteristics of oxynitride glass-ceramics within the Na–K–Mg–Ca–Al–Si–O–N system. Oxynitride glass-ceramic samples were prepared via spark plasma sintering (SPS) with sodium oxide doping levels ranging from 0 wt% to 12 wt%. FESEM analysis revealed changes in sample morphology with increasing sodium content, indicating the formation of granular structures and sodium-rich clusters in the glass matrix. XRD revealed the presence of nanocrystalline phases in doped samples, primarily (Na,Ca)(Si,Al)4O8. IR spectroscopy demonstrated changes in the glass network structure due to sodium, affecting both silicate and aluminum units. Increasing sodium content led to higher crystallinity and a corresponding decrease in sample density. The thermal expansion increased notably with sodium content, attributed to the disruptive effect of sodium ions on the glass-ceramics structure, while thermal conductivity decreased also attributed to this disruption. AC conductivity increased significantly with sodium, indicating enhanced ionic conductivity, while DC conductivity was observed in doped samples at higher temperatures, with activation energies consistent with ionic conduction mechanisms. The exponent-dependent (s) parameter decreased with higher sodium content, suggesting limited ion diffusion.
Investigation of the thrust generated by active isolated hydrofoils via wave-induced ship motion
- Mohammad Sadeghi
- Hamid Zeraatgar
- Mohammad Ghaemi
- Vernengo Giuliano
2025 OCEAN ENGINEERING
Wave Augmented Hydrofoil Technology (WAHT) aims to convert hydrofoil movement, induced by ship motion, into thrust force, and ship's resistance reduction in waves. Despite the growing interest in WAHT, a significant research gap remains in understanding the complex interactions between hydrofoil design parameters and wave-induced thrust generation. A hydrofoil attached to a ship serves dual roles; reducing the ship resistance in waves and generating thrust force. To distinguish the resistance reduction to the thrust generation, this study considers an isolated active hydrofoil without the ship's hull. This approach captures the critical interactions driven by ship motion, while allowing for a focused analysis on thrust generation. The active hydrofoil orientation is harmonically adjusted according to the flow vertical velocity that results in a suitable angle of attack. The generated thrust is studied by varying the hydrofoil rotation angle, aspect ratio, wavelength, and forward speed. The vertical velocity of KRISO Container Ship (KCS) in a range of regular waves is already available where KCS model alone (without WAHT) was simulated using Computational Fluid Dynamics (CFD). Simulation of isolated hydrofoil reveals increase of the vertical velocity, span-to-chord ratio, and forward speed of the hydrofoil enhances thrust force. For the studied cases, a 2.5% enhancement of mean generated power relative to required power in waves is concluded.
Investigation on Swelling of Agar-Based Antibacterial Hydrogels for Hard-To-Heal Wound Dressings
- Paweł Szarlej
- Edyta Piłat
- Przemysław Gnatowski
- Hubert Cieśliński
- Maciej Sienkiewicz
- Justyna Kucińska-Lipka
2025 CHEMMEDCHEM
Despite a wide range of available wound treatments, hard-to-heal wounds still pose a challenge. Hydrogels are often used as dressings for these wounds, because they sustain moisture in the wound environment, supporting the natural healing process. However, it is still not fully understood how physicochemical properties of hydrogel matrix affect the drug release process. Thus, detailed swelling kinetics examination coupled with modeling is needed together with studies on drug release. In this regard, several hydrogels based on plant-derived agar and modified with amikacin were investigated. The main properties of hydrogels were examined focusing on detailed swelling kinetics. Drug release was studied as microbiological activity against E. coli and S. Epidermidis strains. The obtained hydrogels were characterized by high swelling, reaching values in range from 465 to 1300%, fitting the second order kinetics mode and exhibiting the quasi-Fickian diffusion properties. Furthermore, there was no correlation found between swelling properties and antibacterial activity against tested strains. The results confirmed that presented hydrogel materials have desirable properties for application as dressings for hard-to-heal wounds. The suggested compositions are a promising base for modification with other active substances (e.g., regenerative, anti-inflammatory) and studying the broader correlation between swelling and drug release.
ISO test track influence on the EU tyre label noise value
- Truls Berge
- Piotr Mioduszewski
- Maciej Hałucha
- Janusz Bohatkiewicz
2025 APPLIED ACOUSTICS
In 2009, the European Union (EU) introduced a directive governing the labelling of tyres, which underwent revision in 2020. This labelling system encompasses three key parameters related to tyre performance: wet grip (safety), rolling resistance (energy consumption), and external rolling noise (environmental impact). These label values serve as crucial information for customers seeking to purchase replacement tyres for their vehicles. However, the accuracy and reliability of noise measurements have been a concern. Testing conducted across various ISO-standardized tracks has revealed significant inconsistencies in noise levels, with variations of 4–5 dB between tracks. Such discrepancies directly impact the labelling process, introducing uncertainty. This paper presents results of tyre noise measurements conducted on a limited number of ISO test tracks and proposes a methodology to mitigate track-to-track variability. The study exclusively focuses on passenger car tyres. By addressing these inconsistencies, this research aims to enhance the accuracy and reliability of tyre noise labelling, thereby facilitating informed consumer decision-making and promoting environmental sustainability.
Isolation Improvement in MIMO Antenna with a Simple Hybrid Technique of Orthogonal and Inverse Currents
- Manzoor Elahi
- Sławomir Kozieł
- Leifur Leifsson
2025 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
This paper presents a compact high-isolation multiple-input multiple-output (MIMO) antenna developed using a hybrid approach. The proposed technique combines induced orthogonal currents and self-inverse currents to enhance the antenna's performance. Orthogonal currents are generated by strategically etching open slots on the antenna patches, while self-inverse currents are introduced by integration of annular vias. By carefully adjusting the radius and position of the annular vias and optimizing the patch geometry, the design achieves optimal resonance frequency alignment and signicantly improved isolation. The fabricated prototype exhibits an exceptional isolation of 55 dB at 5.75 GHz, accompanied by a realized gain of 6.7 dB. Measured radiation patterns in the ϕ = 0◦ and ϕ = 90◦ planes show excellent agreement with simulated results. The proposed low-prole antenna design has a substantial potential for enhancing MIMO applications in contemporary wireless communication systems.