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Chronic Rhinosinusitis—Microbiological Etiology, Potential Genetic Markers, and Diagnosis
- Michał Michalik
- Beata Krawczyk
2024 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Chronic rhinosinusitis (CRS) is a significant public health problem. Bacterial colonization and impaired mucociliary clearance play a significant role in the inflammatory process. Several inflammatory pathways and host defense elements are altered in CRS, which may contribute to observed differences in the microbiome. To date, researching CRS has been difficult due to limited access to the studied tissue and a lack of available biomarkers. Ongoing scientific research is increasingly based on simple and objective analytical methods, including sensors, detection with PCR, and sequencing. Future research on microbiota and human factors should also include genomics, transcriptomics, and metabolomics approaches. This report analyzes the changes that occur in the paranasal sinuses of people with acute and chronic rhinosinusitis, the composition of the microbiota, the human genetic markers that may shed light on the predisposition to CRS, and the advantages and disadvantages of classical and molecular diagnostic methods, as well as addressing the difficulties of sinusitis treatment.
Circularly Polarized Metalens Antenna Design for 5G NR Sub-6 GHz Communication Systems
- Rao Aziz
- Sławomir Kozieł
2024 AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS
5G NR (new radio) FR1 range refers to as Sub-6GHz band (410MHz to 7125MHz and 3.4GHz to 6GHz). In this paper, the frequency range of interest is from 3.4 to 6GHz, as many cellular companies are focusing on this Sub-6GHz band. A wideband circularly polarized (CP) antenna radiator is designed with diamond shape patches, fed by a microstrip line at the bottom through a rectangular shape wide slot on a ground plane. The proposed CP antenna covering a -10dB bandwidth of 21.52% (5.0 to 6.3GHz) with 3-dB axial ratio (AR) bandwidth of 12.48% (5.1 to 5.8GHz). Furthermore, a metasurface-based lens (metalens) is designed for gain enhancement and fed by 3  1 array of the proposed CP antennas for multibeam operation. The lightweight dual-layer metasurface structure consisting of circular shape unit cell elements are used to implement the lens. For the proof-of-concept, the array of radiating elements is implemented and experimentally validated, which gives a ±18o beam scanning range with a maximum gain of 13dBic at 5.6GHz.
Circulating miRNA profiles and the risk of hemorrhagic transformation after thrombolytic treatment of acute ischemic stroke: a pilot study
- Marcin Stańczak
- Adam Wyszomirski
- Paulina Słonimska
- Barbara Kołodziej
- Bartosz Jabłoński
- Anna Stanisławska-Sachadyn
- Bartosz Karaszewski
2024 Frontiers in Neurology
Background: Hemorrhagic transformation (HT) in acute ischemic stroke is likely to occur in patients treated with intravenous thrombolysis (IVT) and may lead to neurological deterioration and symptomatic intracranial hemorrhage (sICH). Despite the complex inclusion and exclusion criteria for IVT and some useful tools to stratify HT risk, sICH still occurs in approximately 6% of patients because some of the risk factors for this complication remain unknown. Objective: This study aimed to explore whether there are any differences in circulating microRNA (miRNA) profiles between patients who develop HT after thrombolysis and those who do not. Methods: Using qPCR, we quantified the expression of 84 miRNAs in plasma samples collected prior to thrombolytic treatment from 10 individuals who eventually developed HT and 10 patients who did not. For miRNAs that were downregulated (fold change (FC) <0.67) or upregulated (FC >1.5) with p < 0.10, we investigated the tissue specificity and performed KEGG pathway annotation using bioinformatics tools. Owing to the small patient sample size, instead of multivariate analysis with all major known HT risk factors, we matched the results with the admission NIHSS scores only. Results: We observed trends towards downregulation of miR-1-3p, miR-133a-3p, miR-133b and miR-376c-3p, and upregulation of miR-7-5p, miR-17-3p, and miR-296-5p. Previously, the upregulated miR-7-5p was found to be highly expressed in the brain, whereas miR-1, miR-133a-3p and miR-133b appeared to be specific to the muscles and myocardium. Conclusion: miRNA profiles tend to differ between patients who develop HT and those who do not, suggesting that miRNA profiling, likely in association with other omics approaches, may increase the current power of tools predicting thrombolysis-associated sICH in acute ischemic stroke patients. This study represents a free hypothesis-approach pilot study as a continuation from our previous work. Herein, we showed that applying mathematical analyses to extract information from raw big data may result in the identification of new pathophysiological pathways and may complete standard design works.
Classification of Covid-19 using Differential Evolution Chaotic Whale Optimization based Convolutional Neural Network
- D.p. Manoj Kumar
- Sujata N. Patil
- Parameshachari Bidare Divakarachari
- Przemysław Falkowski-Gilski
- R. Suganthi
2024 Pełny tekst Scalable Computing: Practice and Experience
COVID-19, also known as the Coronavirus disease-2019, is an transferrable disease that spreads rapidly, affecting countless individuals and leading to fatalities in this worldwide pandemic. The precise and swift detection of COVID-19 plays a crucial role in managing the pandemic's dissemination. Additionally, it is necessary to recognize COVID-19 quickly and accurately by investigating chest x-ray images. This paper proposed a Differential Evolution Chaotic Whale Optimization Algorithm (DECWOA) based Convolutional Neural Network (CNN) method for identifying and classifying COVID-19 chest X-ray images. The DECWOA based CNN model improves the accuracy and convergence speed of the algorithm. This method is evaluated {by} Chest X-Ray (CXR) dataset and attains better results in terms of accuracy, precision, sensitivity, specificity, and F1-score values of about 99.89}%, 99.83%, 99.81%, 98.92%, and 99.26% correspondingly. The result shows that the proposed DECWOA based CNN model provides accurate and quick identification and classification of COVID-19 compared to existing techniques like ResNet50, VGG-19, and Multi-Model Fusion of Deep Transfer Learning (MMF-DTL) models.
Climate change impact on groundwater resources in sandbar aquifers in southern Baltic coast
- Anna Gumuła-Kawęcka
- Beata Jaworska-Szulc
- Maciej Jefimow
2024 Pełny tekst Scientific Reports
Shallow coastal aquifers are vulnerable hydrosystems controlled by many factors, related to climate, seawater‑freshwater interactions and human activity. Given on‑going climate change, sea level rise and increasing human impact, it is especially true for groundwater resources situated in sandbars. We developed numerical models of unsaturated zone water flow for two sandbars in northern Poland: the Vistula Spit and the Hel Spit using HYDRUS‑1D. The simulations were performed for three types of land use: pine forest, grass cover and bare soil, for 2024–2100 based on weather data and sea level rise forecasts for two emissions scenarios (RCP 4.5 and RCP 8.5). The results present prognosis of groundwater recharge, water table level and water content changeability in near‑term (2023–2040), mid‑term (2041–2060), and long‑term period (2081–2100). Expected sea level rise and decreasing hydraulic gradient of the sandbar aquifers will probably cause in‑land movement of the freshwater– saltwater interface, leading to significant decrease or complete salinization of groundwater resources. The study shows that holistic monitoring including groundwater level and salinization, sea level rise, and metheorological data (precipitation amount and variability, temperature) is crucial for sustainable management of vulnerable aquifers located in sandbars.
Cloud-based system for monitoring loads generated on the quay wall by ship propeller jets
- Mirosław Gerigk
- Teresa Abramowicz-Gerigk
- Łukasz Hapke
- Katarzyna Tetfejer
2024 MARINE STRUCTURES
The paper presents a cloud-based system for monitoring loads generated on the quay wall by ship propeller jets during berthing and unberthing maneuvers. The system provides online measurements of the dynamic pressure generated loads by propellers and warns of exceeding the permissible jet velocities over the seabed protection along the berth. The system has a modular structure consisting of a network of pressure sensors, information mapping server, communication module and web server. The suitability of the system was confirmed during two years of operation in Port of Gdynia. The open architecture of the system allows for its further extension with additional berths and integration with the smart port system.
Cluster-spin-glass behavior in new ternary RE2PtGe3 compounds (RE = Tb, Dy, Ho)
- Leszek Litzbarski
- Michał Winiarski
- Igor Oshchapovsky
- Przemysław Skokowski
- Karol Synoradzki
- Tomasz Klimczuk
- Bartłomiej Andrzejewski
2024 Materials Research Express
Two new ternary germanides Tb2Pt1.2Ge2.8, Dy2Pt1.15Ge2.85 and one already known germanium Ho2Pt1.1Ge2.9.were synthesized using an arc melting technique. The obtained samples were investigated by powder X-ray diffraction, which indicated that all of them crystallized in a hexagonal structure with P6/mmm (no. 191) space group. This structure is a disordered variant of the AlB2 aristotype that favors the formation of a spin-glass-like state. The physical properties were examined by measuring magnetic susceptibility, heat capacity and electrical resistance. Experiments indicated that all of the compounds can be classified as cluster-spin-glasses with the freezing temperature of Tf = 12.0 K, Tf = 6.0 K and Tf = 2.9 K for Tb2Pt1.2Ge2.8, Dy2Pt1.15Ge2.85 and Ho2Pt1.1Ge2.9 respectively.
c-Myc inhibition and p21 modulation contribute to unsymmetrical bisacridines-induced apoptosis and senescence in pancreatic cancer cells
- Agnieszka Kurdyn
- Monika Pawłowska
- Ewa Paluszkiewicz
- Miroslawa Cichorek
- Ewa Augustin
2024 Pharmacological Reports
Background Pancreatic cancer (PC) is one of the most aggressive cancers and is the seventh leading cause of cancer-related death worldwide. PC is characterized by rapid progression and resistance to conventional treatments. Mutations in KRAS, CDKN2A, TP53, SMAD4/DPC4, and MYC are major genetic alterations associated with poor treatment outcomes in patients with PC. Therefore, optimizing PC therapy is a tremendous challenge. Unsymmetrical bisacridines (UAs), synthesized by our group, are new promising compounds that have exhibited high cytotoxicity and antitumor activity against several solid tumors, including pancreatic cancer. Methods The cellular effects induced by UAs in PC cells were evaluated by MTT assay (cell growth inhibition), flow cytometry, and fluorescence and light microscopy (cell cycle distribution, apoptosis, and senescence detection). Analysis of the effects of UAs on the levels of proteins (c-Myc, p53, SMAD4, p21, and p16) was performed by Western blotting. Results Apoptosis was the main triggered mechanism of death after UAs treatment, and induction of the SMAD4 protein can facilitate this process. c-Myc, which is one of the molecular targets of UAs, can participate in the induction of cell death in a p53-independent manner. Moreover, UAs can also induce accelerated senescence through the upregulation of p21. Notably, senescent cells can die via apoptosis after prolonged exposure to UAs. Conclusions UAs have emerged as potent anticancer agents that induce apoptosis by inhibiting c-Myc protein and triggering cellular senescence in a dose-dependent manner by increasing p21 levels. Thus, UAs exhibit desirable features as promising candidates for future pancreatic anticancer therapies.
CNN-CLFFA: Support Mobile Edge Computing in Transportation Cyber Physical System
- Ashok Bhansali
- Raj Kumar Patra
- Parameshachari Bidare Divakarachari
- Przemysław Falkowski-Gilski
- Gandla Shivakanth
- Sujatha N. Patil
2024 Pełny tekst IEEE Access
In the present scenario, the transportation Cyber Physical System (CPS) improves the reliability and efficiency of the transportation systems by enhancing the interactions between the physical and cyber systems. With the provision of better storage ability and enhanced computing, cloud computing extends transportation CPS in Mobile Edge Computing (MEC). By inspecting the existing literatures, the cloud computing cannot fulfill the requirements in transportation CPS like lower context-awareness and latency. For enhancing the context-awareness and reducing the latency in a realistic MEC environment, an efficient portable deep learning model: Convolutional Neural Network (CNN) with Chaotic Lévy Flight based Firefly Algorithm (CLFFA) is implemented in this article. In the CNN model, the CLFFA selects the appropriate hyper-parameters or reduces the redundant parameters that results in minimal model size and inference latency than the traditional CNN models. Additionally, the CNN-CLFFA model significantly outperformed the existing models by means of recall, accuracy, F1-score, and precision on the benchmark datasets like German Traffic Sign Recognition Benchmark (GTSRB), MIOvision Traffic Camera Dataset (MIO-TCD) classification, and VCifar-100 datasets. The numerical analysis demonstrates that the CNN-CLFFA model obtained maximum accuracy of 99.02%, 99.11%, and 99.03% on the VCifar-100, MIO-TCD, and GTSRB-T datasets, which are superior to the traditional models.
CO2 capture enhancement by metal oxides impregnated coal fly ash: a breakthrough adsorption study
- Umar Irshad
- Zaheer Aslam
- Sara Sumbal
- Ali Hamza
- Zaka- ur-Rehman
2024 ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Coal fired power plants are significant contributors to CO2 emissions and produce solid waste in the form of coal fly ash, posing severe environmental challenges. This study explores the application of dry-impregnated coal fly ash for CO2 capture from gas stream. The modification of coal fly ash was achieved using alkaline earth metal oxides, specifically CaO and MgO, to alter its physical and chemical properties. Characterization techniques like X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET (Brunauer–Emmett–Teller) analysis were employed for physio-chemical changes in the adsorbent. Breakthrough experiments were conducted using a laboratory-scale fixed packed-bed reactor to assess the influence of temperature and gas flow rate on CO2 adsorption. Among the synthesized sorbents, calcium oxide-impregnated ash showed the highest CO2 uptake capacity, achieving 9.41 mg/g at 30 °C and a flow rate of 20 L/hr under atmospheric pressure. Isotherm modeling indicated a heterogeneous adsorbent surface, with the data best fitting the Sips isotherm model. Furthermore, the adsorption data conformed well to the Yoon-Nelson and Thomas kinetic models, affirming their relevance in characterizing the adsorption process under varying conditions. This research emphasizes the potential of coal fly ash—an abundant, cost-free material—as an effective CO2 adsorbent, contributing to both CO2 mitigation and landfill waste reduction.
CO2 capture through direct-contact condensation in a spray ejector condenser and T- junction separator
- Milad Amiri
- Michał Klugmann
- Jaroslaw Mikielewicz
- Paweł Ziółkowski
- Dariusz Mikielewicz
2024 INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
The design principle underlying the steam condensation and CO2 purification in a gas power plant with a focus on reducing CO2 emissions encompasses the deployment of a spray ejector condenser (SEC) and separator. This innovative system facilitates direct-contact condensation of steam with non-condensable gas (CO2) by inter acting with a spray of subcooled water, seamlessly integrated with a T-junction separator mechanism aimed at yielding pure CO2. Because of decreased convective heat transfer and heightened diffusion resistance between the subcooled water and steam phases caused by CO2, the research examined the effects of various thermo physical parameters of the injected water, specifically temperature (20–40 with Steam Mass Flow Rates (2.2–4.6 g s ◦ C) and pressure (12–16 bar) along ) to improve heat transfer rates within the SEC. The SEC utilizes a Eulerian- Eulerian multiphase model, wherein water is considered the continuous phase while the mixture of steam and CO2 constitutes the dispersed phase. Turbulence within the ejector is represented applying standard k model. Furthermore, the separator employs turbulence and operates in three dimensions using the control volume method. The simulation of turbulent two-phase flow in the gas-liquid T-junction separator is conducted utilizing K standard ε ε turbulence model and a mixture model. The results imply that the maximum temperature difference (ΔT) between inlet and outlet of SEC is observed when the steam mass flow rate is 2.2 (g/s) without CO2, while the presence of CO2 leads to a reduction in ΔT. Additionally, the performance of the SEC is notably affected by the optimal settings of water temperature and pressure, where lower coolant water temperatures (20 ◦ C) and higher water pressures (16 bar) contribute to improved condensation performance. Furthermore, the study ex plores the decrease in separation efficiency associated with elevated inlet mass flow rate, attributed to maldis tribution in the vertical impact T-junction separator.
CO2 capture using steam ejector condenser under electro hydrodynamic actuator with non-condensable gas and cyclone separator: A numerical study
- Milad Amiri
- Jaroslaw Mikielewicz
- Dariusz Mikielewicz
2024 SEPARATION AND PURIFICATION TECHNOLOGY
The concept for condensation of steam and CO2 separation in a negative CO2 emission gas power plant involves the utilization of a steam ejector condenser (SEC) for direct-contact condensation of vapor with inert gas (CO2) on a spray of subcooled liquid, integrated with a separator to produce pure CO2. Due to the increasing diffusion resistance and reduced convective heat transfer between the steam and subcooled water phases in the presence of non-condensable gas (CO2), the study utilized an electrohydrodynamic (EHD) actuator to enhance heat transfer rate in the SEC. To optimize CO2 purification, the effect of single, dual and quadruple inlets on separation efficiency was analysed. In the SEC, the Eulerian-Eulerian multiphase model is employed, treating water as the continuous phase and the compressible gas mixture (steam and CO2) as the dispersed phase. The standard k-ε model is chosen to depict the turbulence in the ejector. The separator is transient, turbulent, and threedimensional, using the control volume method. The RSM turbulent model and mixture model are utilized to simulate the turbulent two-phase flow in the gas–liquid separator. The findings indicated that when the mass flux of steam and voltage are increased, the condensation heat transfer coefficient also increases. For a mass flux of steam of 51 ( kg m2 .s ), the condensation heat transfer coefficients were measured to be 0.98, 1.029, 1.08, and 1.134 ( MW m2.K) at electrode voltages of 0, 20, 25, and 30 kV, respectively. In addition, a single-inlet cyclone attains a separation efficiency of 95.1 %, while incorporating two inlets improves the performance to 97.9 %. However, the most remarkable outcome is witnessed in cyclones with four inlets, where an impressive separation efficiency of 99.9 % is achieved.
Co-gasification of waste biomass-low grade coal mix using downdraft gasifier coupled with dual-fuel engine system: Multi-objective optimization with hybrid approach using RSM and Grey Wolf Optimizer
- Thanh Tuan Le
- Prabhakar Sharma
- Bhaskor Jyoti Bora
- Jerzy Kowalski
- Sameh M. Osman
- Duc Trong Nguyen Le
- Thanh Hai Truong
- Huu Cuong Le
- Prabhu Paramasivam
2024 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
The looming global crisis over increasing greenhouse gases and rapid depletion of fossil fuels are the motivation factors for researchers to search for alternative fuels. There is a need for more sustainable and less polluting fuels for internal combustion engines. Biomass offers significant potential as a feed material for gasification to produce gaseous fuel. It is carbon neutral, versatile, and abundant on earth. The present study thus explores a mix of different feedstocks, such as mahua wood and low-grade coal for downdraft gasifiers. The resultant producer gas (PG), after cooling-cleaning will be used as the gaseous fuel to run the diesel engine in dual-fuel mode, while a tiny quantity of linseed biodiesel-diesel blends as B20 (20 % biodiesel + 80 % diesel) will be supplied as injected pilot fuel. The data from experimental work at different engine operation settings was employed to develop a prediction-optimization model using a twin approach of RSM and Grey wolf optimization (GWO). The three control factors for the engine were compression ratio (CR) 17 – 17.5 – 18, equivalence ratio 0.12–0.41, and engine loads in the range of 10–100 % were used to collect data on response variables i.e., brake-thermal efficiency (BTE) and emission data (CO2, NOx, UHC, and CO). A comparative approach of RSM and GWO was utilized for the multi-objective optimization revealing the best results were attained at 17.65 CR, 0.4 ER, 82.55 % engine load in the case of GWO.
Cold plasma treatment of tannic acid as a green technology for the fabrication of advanced cross-linkers for bioactive collagen/gelatin hydrogels
- Beata Kaczmarek-Szczepańska
- Marcin Wekwejt
- Anna Pałubicka
- Anna Michno
- Lidia Zasada
- Amir M. Alsharabasy
2024 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
Tannic acid (TA) is a natural compound studied as the cross-linker for biopolymers due to its ability to form hydrogen bonds. There are different methods to improve its reactivity and effectiveness to be used as a modifier for biopolymeric materials. This work employed plasma to modify tannic acid TA, which was then used as a cross-linker for fabricating collagen/gelatin scaffolds. Plasma treatment did not cause any significant changes in the structure of TA, and the resulting oxidized TA showed a higher antioxidant activity than that without treatment. Adding TA to collagen/gelatin scaffolds improved their mechanical properties and stability. Moreover, the obtained plasma-treated TA-containing scaffolds showed antibacterial properties and were non-hemolytic, with improved cytocompatibility towards human dermal fibroblasts. These results suggest the suitability of plasma treatment as a green technology for the modification of TA towards the development of advanced TA-crosslinked hydrogels for various biomedical applications.
Collaborative development model and strategies of multi-energy industry clusters: Multi-indicators analysis affecting the development of coastal energy clusters
- Chen Xiu
- Anna Lis
2024 ENERGY
The paper explores Coastal Energy-Based Industrial Clusters (EBICs) and their role in advancing energy efficiency and sustainability through collaborative innovation. Economic growth theory and energy sustainability have been introduced into industrial clusters to illustrate indicators that have a greater impact on the development of EBICs. This paper proposes an EBICs development model based on the Cobb-Douglas function, in which accounts for various factors that drive the progress of such clusters. The outcomes of the economic model also provide insights into how the interaction of various factors affects the economic growth of EBICs and their eventual dominance in the energy market of coastal regions, dependent on gradually investing in areas such as research and development (R&D). Different development strategies demonstrate that the final development of a cluster has low dependence on the cluster's initial advantages. The study also illustrates how clusters can gradually monopolize the energy market, even with initial disadvantages. Through quantitative analysis, it showcases the transformation process of developing advantageous clusters into sub-clusters. Next, an energy symbiosis framework for coastal is proposed, which places greater emphasis on the multi-energy complementary system and reduces production costs. Finally, this paper also sheds light on shaping energy strategies for public authorities who shape economic policies at various levels of aggregation and in diverse dimensions.
Collaborative planning? Not yet seen in Poland. Identifying procedural gaps in the planning system 2003–2023
- Izabela Mironowicz
- Michał Marek Ciesielski
2024 Pełny tekst Bulletin of Geography. Socio-economic Series
Collaborative planning aims to increase the legitimacy of decision-making in spatial development. In this approach, planning involves debate and engagement in discourse, and participation and interaction between actors are thus at the heart of the planning process. This article examines whether the planning system in Poland as defined for the period 2003–2025 provides a level of participation and deliberation and other qualities that together allow it to be classified as a collaborative model. The legal procedures in the most commonly used planning instruments are therefore analysed in detail to determine whether they provide honest, open, equal and transparent access to the decision-making process to all stakeholders. The analysis reveals numerous deficiencies in the planning procedures that undermine the collaborative nature of spatial planning in Poland. The study summarises the experience of twenty years of spatial planning practice in Poland and provides a useful starting point for assessing the new planning system that has gradually been being implemented since 2023.
Colossus from Algebron – Gamification as a Tool to Engage Students in Learning Mathematics
- Barbara Wikieł
- Joanna Mytnik
2024 Scientific Journal of Gdynia Maritime University
Gamification is a tool that allows for high engagement in performing tasks that have been previously considered difficult or uninteresting. It works exceptionally well in education as it supports students in developing habits of learning and provides them with a visual representation of their progress in acquiring knowledge and skills. Skillful design of gamified academic courses enables the achievement of educational goals set by both the students and the academic teachers. Gamification is helpful for subjects that seem challenging, require a significant amount of effort, or are simply perceived by students as uninteresting or useless. The purpose of the paper is to discuss various aspects of engaging students in the process of learning mathematics by gamification of linear algebra.
Combined effect of nitrogen-doped carbon and NiCo2O4 for electrochemical water splitting
- Laura Kubińska
- Mariusz Szkoda
- Malgorzata Skorupska
- Patrycja Grabowska
- Marta Gajewska
- Jerzy P. Lukaszewicz
- Anna Ilnicka
2024 Scientific Reports
Electrocatalytic water splitting for green hydrogen production necessitates effective electrocatalysts. Currently, commercial catalysts are primarily platinum-based. Therefore, finding catalysts with comparable catalytic activity but lower cost is essential. This paper describes spinel-structured catalysts containing nickel cobaltite NiCo2O4, graphene, and additionally doped with heteroatoms. The structure and elemental composition of the obtained materials were analyzed by research methods such as TEM, SEM-EDX, XRD, XPS, and Raman spectroscopy. The electrochemical measurements showed that hybrid materials containing nickel cobaltite NiCo2O4 doped with graphene are highly active catalysts in the hydrogen evolution reaction (Tafel slopes = 91 mV dec−1, overpotential = 468 mV and onset potential = -339 mV), while in the oxygen evolution reaction (Tafel slopes = 51 mV dec−1, overpotential = 1752 mV and onset potential = 370 mV), bare NiCo2O4 without the addition of carbon has a worse activity (for HER: Tafel slopes = 120 mV dec−1, overpotential - does not achieve and onset potential = -404 mV, for OER: Tafel slopes = 54 mV dec−1, overpotential = 1796 mV and onset potential = 410 mV). In terms of stability, comparable results were obtained for each synthesized compound for both the HER and OER reactions.
Comment on permeability conditions in finite element simulation of bone fracture healing
- Agnieszka Sabik
2024 Pełny tekst COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
The most popular model of the bone healing considers the fracture callus as poroelastic medium. As such it requires an assumption of the callus’ external permeability. In this work a systematic study of the influence of the permeability of the callus boundary on the simulated bone healing progress is performed. The results show, that these conditions starts to play significant role with the decrease of the callus size. Typically enforced impermeability inhibits the progress of healing during simulation. A remedy for this effect is imposing drainage conditions at the callus’ boundary.
Compact Substrate-Integrated Hexagonal Cavity-Backed Self-Hexaplexing Antenna for Sub-6 GHz Applications
- Vijay Jayaprakash
- Chandu Ds
- Rusan Kumar Barik
- Sławomir Kozieł
2024 Pełny tekst IEEE Access
A self-multiplexing SIW antenna based on hexagonal SIW cavity is proposed. The self-hexaplexing antenna consists of different sizes of resonating elements, which provide the hexaband operations. The antenna resonates at 5 GHz, 5.17 GHz, 5.32 GHz, 5.53 GHz, 5.62 GHz, and 5.72 GHz by employing different slot lengths between the resonating elements. The proposed antenna provides the individual tunable characteristics of the operating frequencies without changing the other resonant frequencies. The self-hexaplexing antenna exhibits a port isolation of > 29 dB between the resonating elements with a low frequency ratio of 1.14. The simulated gains of the antenna are 5.32 dBi, 5.68 dBi, 5.41 dBi, 5.91 dBi, 5.43 dBi and 5.14 dBi at the corresponding operating frequencies. The proposed self-hexaplexer operates in the NR band (n46) that can be suitable for communication system applications.