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Gdańsk University of Technology

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Publications from the year 2024

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  • Characterization of Corrosion-Induced Fracture in Reinforced Concrete Beams Using Electrical Potential, Ultrasound and Low-Frequency Vibration
    • Tomasz Ferenc
    • Erwin Wojtczak
    • Błażej Meronk
    • Jacek Ryl
    • Krzysztof Wilde
    • Magdalena Rucka
    2024 Full text JOURNAL OF NONDESTRUCTIVE EVALUATION

    The paper deals with the non-destructive experimental testing of the reinforced concrete beams under progressive corrosion. A series of experiments using electrical potential, ultrasound and low-frequency vibrations techniques are reported. Electrical potential and natural frequencies were used to characterise and monitor the corrosion process at its initial state. The P-wave velocity measurements were proved to be effective in quantitative assessment of the level of corrosion as it progresses. The possibility of early detection of damage using a proposed damage index and diagnostic framework is promising for possible applications in the non-invasive diagnostics of reinforced concrete elements.

  • Charakterystyka i zastosowanie związków powierzchniowo czynnych w produktach detergentowych. Skrypt do ćwiczeń
    • Patrycja Szumała
    2024

    Niniejszy skrypt zawiera podstawy teoretyczne wprowadzające w tematykę związków powierzchniowo czynnych znajdujących zastosowanie w produktach detergentowych. Ponadto przedstawiono charakterystykę innych, dodatkowych składników takich produktów, jak również opis specjalistycznych detergentów przemysłowych. Opracowanie jest przeznaczone przede wszystkim dla studentów technologii chemicznej, realizujących zajęcia z przedmiotu technologia związków powierzchniowo czynnych, w ramach którego prowadzone są też ujęte w skrypcie zajęcia laboratoryjne. Jednak zawarte treści mogą się stać użyteczne dla wszystkich osób zainteresowanych produktami detergentowymi, także ze środowiska przemysłowego.

  • Charge density wave, enhanced mobility, and large nonsaturating magnetoresistance across the magnetic states of HoNiC2 and ErNiC2
    • Kamil Kolincio
    • Marta Roman
    • Fabian Garmroudi
    • Michael Parzer
    • Ernst Bauer
    • Herwig Michor
    2024 Full text PHYSICAL REVIEW B

    We report on magnetotransport and thermoelectric properties of two ternary carbides HoNiC2 and ErNiC2 hosting both charge density wave and long-range magnetic order. In the charge density wave state, both compounds show relatively large magnetoresistance MR ≈ 150% in HoNiC2 and ≈ 70%in ErNiC2 at a magnetic field of 9 T and temperature as low as 2 K. This positive field-linear magnetoresistance shows no signatures of saturation. Our combined analysis of diagonal and off-diagonal transport responses reveals electronic mobility values on the order of 103 cm2 V−1 s−1 at 2 K. Both the elevated mobility and related enhanced magnetoresistance persist in the zero-field antiferromagnetic ground state and survive the field-induced crossovers through metamagnetic to field-aligned ferromagnetic states. The robustness of the high-mobility Fermi surface pockets across the magnetically ordered states suggests that the charge density wave is not suppressed but coexists with long-range magnetism in the entire dome of the magnetically ordered states.

  • Chat GPT Wrote It: What HCI Educators Can Learn from their Students?
    • Marcin Sikorski
    2024

    Recently students, teachers, and researchers equally have become impressed by Generative AI (GenAI) tools, with ChatGPT at the top. However, numerous concerns about the GenAI-related threats to academic integrity and the validity of learning outcomes are emerging. This problem is also vivid in Human-Computer Interaction (HCI) education since students can use GenAI tools to rapidly generate ideas, user interface templates, screen graphics and mock-ups, or entire user research programmes. This paper presents the results of a small-scale survey performed with a group of HCI students regarding their experiences and expectations regarding the use of GenAI tools in their current HCI course, as well as expected GenAI-relevant university policies. Conclusions from this study can be informative for HCI teachers considering the potential use of GenAI tools in their classes and for university managers in the broader context of engineering university education, regarding computer science in particular. Also, results of this study can be useful for the educational management involving students as the teaching process stakeholders in the context of developing institutional policies as to the allowed use of GenAI tools.

  • Chemical and biological characterization of Ocimum basilicum L. phenolic extract and essential oil derived through ultrasound and microwave-assisted extraction techniques
    • Sarah Hamid
    • Naima Fadloun Oukil
    • Hamza Moussa
    • Nadjet Djihad
    • Marika Mróz
    • Barbara Kusznierewicz
    • Amel Attia
    • Katia Djenadi
    • Malik Mohamed Mahdjoub
    • Mustapha Mounir Bouhenna
    • Farid Chebrouk
    2024 Food Bioscience

    Plant-derived bioactive molecules are increasingly utilized in food processing as natural additives, driven by a growing interest in healthier lifestyles. This trend has spurred industries to reformulate products to meet the demands of health-conscious consumers. This study investigates the phenolic extract and essential oil of O. basilicum L. obtained via ultrasound-assisted extraction and microwave-assisted extraction, respectively. Characterization using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS) for the basil phenolic extract (BPE) and Gas Chromatography-Mass Spectrometry (GCMS) for the basil essential oil (BEO) identified 82 compounds in BPE and 51 compounds, with rosmarinic acid and estragole as the main constituents, respectively. Both BPE and BEO exhibited significant antioxidant capacity. BPE showed higher antioxidant activity, with IC50 values of 0.740 ± 0.023 mg/mL against DPPH•, 0.408 ± 0.02 mg/mL for ABTS+•, and 0.289 ± 0.02 mg/mL for iron chelation. Conversely, BEO demonstrated IC50 values of 16.296 ± 0.394 mg/mL, 0.6870 ± 0.0203 mg/mL, and 3.9 ± 0.12 mg/mL for DPPH•, ABTS+• scavenging assays, and iron chelation, respectively. The growth inhibitory effect of BEO surpassed that of BPE against microbial strains, achieving total growth inhibition against C. albicans with a minimal inhibitory concentration (MIC) value of 0.04 mg/mL. BPE exhibited inhibitory effects against MRSA with a zone of inhibition of 19 ± 1.15 mm, while the lowest MIC value was observed against E. coli at 0.38 ± 0.03 mg/mL. These findings underling basil’s potential health-boosting, emphasizing its abundance in phenolic and volatile compounds.

  • Chemical investigation on the mechanism and kinetics of the atmospheric degradation reaction of Trichlorofluoroethene by OH⋅ and Its subsequent fate in the presence of O2/NOx
    • Abolfazl Shiroudi
    • Jacek Czub
    • Mohammednoor Altarawneh
    2024 CHEMPHYSCHEM

    The M06-2X/6-311++G(d,p) level of theory was used to examine the degradation of Trichlorofluoroethene (TCFE) initiated by OH⋅ radicals. Additionally, the coupled-cluster single-double with triple perturbative [CCSD(T)] method was employed to refine the single-point energies using the complete basis set extrapolation approach. The results indicated that OH-addition is the dominant pathway. OH⋅ adds to both the C1 and C2 carbons, resulting in the formation of the C(OH)Cl2−⋅CClF and ⋅CCl2−C(OH)ClF species. The associated barrier heights were determined to be 1.11 and −0.99 kcal mol−1, respectively. Furthermore, the energetic and thermodynamic parameters show that pathway 1 exhibits greater exothermicity and exergonicity compared to pathway 2, with differences of 8.11 and 8.21 kcal mol−1, correspondingly. The primary pathway involves OH addition to the C2 position, with a rate constant of 6.2×10−13 cm3 molecule−1 sec−1 at 298 K. This analysis served to estimate the atmospheric lifetime, along with the photochemical ozone creation potential (POCP) and ozone depletion potential (ODP). It yielded an atmospheric lifetime of 8.49 days, an ODP of 4.8×10−4, and a POCP value of 2.99, respectively. Radiative forcing efficiencies were also estimated at the M06-2X/6-311++G(d,p) level. Global warming potentials (GWPs) were calculated for 20, 100, and 500 years, resulting in values of 9.61, 2.61, and 0.74, respectively. TCFE is not expected to make a significant contribution to the radiative forcing of climate change. The results obtained from the time-dependent density functional theory (TDDFT) indicated that TCFE and its energized adducts are unable to photolysis under sunlight in the UV and visible spectrum. Secondary reactions involve the [TCFE-OH−O2]⋅ peroxy radical, leading subsequently to the [TCFE−OH−O]⋅ alkoxy radical. It was found that the alkoxy radical resulting from the peroxy radical can lead to the formation of phosgene (COCl2) and carbonyl chloride fluoride (CClFO), with phosgene being the primary product.

  • Chemical Structure and Thermal Properties versus Accelerated Aging of Bio-Based Poly(ether-urethanes) with Modified Hard Segments
    • Julia Godlewska
    • Joanna Smorawska
    • Ewa Głowińska
    2024 MOLECULES

    Aging of polymers is a natural process that occurs during their usage and storage. Predicting the lifetime of polymers is a crucial aspect that should be considered at the design stage. In this paper, a series of bio-based thermoplastic poly(ether-urethane) elastomers (bio-TPUs) with modified hard segments were synthesized and investigated to understand the structural and property changes triggered by accelerated aging. The bio-TPUs were synthesized at an equimolar ratio of reagents using the prepolymer method with the use of bio-based poly(trimethylene ether) glycol, bio-based 1,3-propanediol, and hexamethylene diisocyanate or hexamethylene diisocyanate/partially bio-based diisocyanate mixtures. The polymerization reaction was catalyzed by dibutyltin dilaurate (DBTDL). The structural and property changes after accelerated aging under thermal and hydrothermal conditions were determined using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). Among other findings, it was observed that both the reference and aged bio-TPUs decomposed in two main stages and exhibited thermal stability up to approximately 300 °C. Based on the research conducted, it was found that accelerated aging impacts the supramolecular structure of TPUs.

  • CHEMOTHERAPY-MEDIATED COMPLICATIONS OF WOUND HEALING. AN UNDERSTUDIED SIDE EFFECT
    • Paulina Słonimska
    • Paweł Sachadyn
    • Jacek Zieliński
    • Marcin Skrzypski
    • Michał Pikuła
    2024 Full text Advances in Wound Care

    Significance: Chemotherapy is a primary method to treat cancer, but while cytotoxic drugs are designed to target rapidly dividing cancer cells, they can also affect other cell types, including dermal cells and macrophages involved in wound healing, which often leads to the development of chronic wounds. The situation becomes even more severe when chemotherapy is combined with surgical tumor excision. Recent advances: Despite its significant impact on patients' recovery from surgery, the issue of delayed wound healing in individuals undergoing chemotherapy remains inadequately explored. Critical Issues: This review aims to analyze the harmful impact of chemotherapy on wound healing. The analysis showed that chemotherapy drugs could inhibit cellular metabolism, cell division, and angiogenesis and lead to nerve damage. They impede the migration of cells into the wound and reduce the production of extracellular matrix. At the molecular level, they interfere with replication, transcription, translation, and cell signaling. This work reviews skin problems that patients may experience during and after chemotherapy and demonstrates insights into the cellular and molecular mechanisms of these pathologies. Future directions: In the future, the problem of impaired wound healing in patients treated with chemotherapy may be addressed by cell therapies like autologous keratinocyte transplantation, which has already proved effective in this case. Epigenetic intervention to mitigate the side effects of chemotherapy is also worth considering, but epigenetic consequences of chemotherapy on skin cells are largely unknown and should be investigated.

  • Chitosan-based nanomaterials for removal of water pollutants
    • Mehvish Mumtaz
    • Nazim Hussain
    • Sidra Salam
    • Hafiz Muhammad Azam Husnain
    • Natalia Łukasik
    • Tak H. Kim
    • Jose Cleiton Sousa dos Santos
    • Jens Ejbye Schmidt
    2024

    The rise of micropollutants presents a significant threat to both the environment and human well-being, requiring effective strategies for their mitigation. Chitin serves as the precursor for chitosan, composed of two monomers featuring acetamido and amino groups. Chitosan possesses several noteworthy attributes, including its ability to bind water and fat, humidity content, solubility, consistent molecular weight, and various degrees of deacetylation, all of which facilitate surface functionalization. To enhance quality and effectiveness, chitosan can be combined with other adsorbent and/or functional nanomaterials to produce chitosan-based nanocomposites with distinct functionalities for various applications. These nanocomposites offer unique advantages in combating environmental issues. Examples of such nanocomposites include chitosan-grafted carbon nanoonions, polymer–chitosan blends, chitosan–clay mineral composites, chitosan–graphene oxide nanocomposites, magnetic chitosan, chitosan-based foams and sponges, and chitosan/activated carbon composites. Each of these nanohybrid materials plays a crucial role in selectively removing specific types of environmental contaminants. This chapter provides a recent perspective on innovative chitosan-based nanohybrids designed for the elimination of impurities from the environment. These nanohybrids exhibit diverse functions, including adsorption of contaminants, humus removal, extraction of heavy metals and metal ions, and reduction of inanimate impurities such as nitrate, borate, and phosphate. The adsorption kinetics of these chitosan-based nanocomposites have also been thoroughly reviewed, offering valuable insights for further research. Additionally, a comparative analysis of different chitosan-supported composites is conducted to provide potential methodologies for enhancing efficacy and fostering the development of novel compounds for environmental remediation.

  • Chitosan-coated coconut shell composite: A solution for treatment of Cr(III)-contaminated tannery wastewater
    • Tonni Agustiono Kurniawan
    • Fatima Batool
    • Ayesha Mohyuddin
    • Hui Hwang Goh
    • Mohd Hafiz Dzarfan Othman
    • Faissal Aziz
    • Abdelkader Anouzla
    • Hussein Al-Hazmi
    • Kit Wayne Chew
    2024 Journal of the Taiwan Institute of Chemical Engineers

    Tannery industry generates a large amount of Cr(III)-contaminated wastewater daily. Unless properly treated, not only this effluent contaminates the water body, but also damages the environment and threatens public health. This batch study investigates the feasibility of chitosan-coated coconut shells as a low-cost material for removing Cr(III) from tannery wastewater. Both chitosan and coconut shell (CS) waste are abundantly available from local agricultural and fishery industries. To enhance its treatment performance for Cr(III) removal, the CS was coated with chitosan as a composite. To sustain its cost-effectiveness, the saturated composite was regenerated with HNO3. Its performance for Cr(III) removal was evaluated and compared to other low-cost adsorbents in previous work. At the same initial concentration of 20 mg/L, it was found that the composite had a higher Cr(III) removal (97%) than the chitosan alone under the optimized conditions of 4 g/L of dose, pH 6.5, 200 rpm of agitation speed, and 1 h of reaction time. The isotherm of Cr(III) removal by the adsorbents followed the Langmuir model, while the pseudo-second order reaction was representative to simulate the adsorption data. The Cr(III) removal by the composite was based on attractive columbic forces between the negative charge of the adsorbent's surface and the positive charge of the metal cation. The negative value of ΔG thermodynamic parameter suggests the spontaneous nature of adsorption. The efficiency of machine learning regression (MLR) model was assessed in predicting the experimental data of adsorption. In spite of promising results, treated effluents still could not comply with the required limit of discharge standards of less than 0.5 mg/L mandated by local legislation. Therefore, a subsequent treatment using activated sludge is required. Overall, this work reveals a contribution of unused resources from the coconut and shrimp industries in the form of composite for protecting the aquatic environment.

  • Chronic Rhinosinusitis—Microbiological Etiology, Potential Genetic Markers, and Diagnosis
    • Michał Michalik
    • Beata Krawczyk
    2024 Full text 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 Full text 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 Full text 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.

  • 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.

  • 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 Full text 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 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.