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  • Biuro Młodych Naukowców – z myślą o młodych naukowcach PG
    • Agnieszka Lendzion
    2024 Pełny tekst Pismo PG

    Biuro Młodych Naukowców to jednostka administracji centralnej powstała w lutym 2024 r. z myślą o szerokim wsparciu młodych naukowców Politechniki Gdańskiej. Do zadań Biura należą m.in.: inicjowanie i prowadzenie szeroko rozumianych działań na rzecz młodych naukowców, wsparcie Zespołu Młodych Naukowców, ale także koordynowanie działań zaplanowanych w Strategii HR4R PG oraz innych związanych z utrzymaniem przez Uczelnię wyróżnienia HR Excellence in Research oraz nadzór merytoryczny nad realizacją projektów Funduszy Europejskich dla Rozwoju Społecznego (FERS).

  • Błędy projektowe i wykonawcze płyty fundamentowej garażu podziemnego
    • Maciej Niedostatkiewicz
    • Tomasz Majewski
    2024

    W artykule przedstawiono opis uszkodzeń płyty fundamentowej garażu podziemnego, która została błędnie zaprojektowana, a następnie wykonana w sposób niezgodny z zasadami wiedzy technicznej. Bezpośrednio po zakończeniu realizacji płyty fundamentowej na jej powierzchni wystąpiły intensywne zarysowania, które miały charakter nieustabilizowany i ulegały rozwojowi w czasie. Wykonana w ramach prac wykończeniowych posadzka również uległa zarysowaniu. W pracy przedstawiono propozycje zakresu prac naprawczych zarówno samej płyty fundamentowej, jak i uszkodzonej posadzki tj. górnej powierzchni wykończonej zasypką utwardzoną powierzchniowo.

  • Bodybuilders and high-level meat consumers’ behavior towards rabbit, beef, chicken, turkey, and lamb meat: A comparative review
    • Shahida Anusha Siddiqui
    • Shuva Bhowmik
    • Maliha Afreen
    • İlknur Ucak
    • Ali Ikram
    • Francesca Gerini
    • Mohammad Mehdizadeh
    • Raphael D. Ayivi
    • Roberto Castro Munoz
    2024 NUTRITION

    In bodybuilders’ diets, protein plays a crucial role in supporting muscle growth and repairing damaged muscle tissue. These individuals meet their protein needs by combining dietary sources with supplements. Animal-based proteins are often preferred over plant-based proteins because they are believed to better support muscle protein synthesis. This review explores the meat consumption patterns of bodybuilders and high-level meat consumers, focusing on rabbit, beef, chicken, turkey, and lamb. We describe and compare the types of meat bodybuilders commonly consume and provide an overview of protein supplements, including meat-based options, plant-based alternatives, and whey-based products. Our aim is to gain insight into the dietary preferences of bodybuilders and high-level meat consumers, considering their nutritional requirements and the potential effect on the meat industry. We conducted an extensive search across various databases, including Scopus, Web of Science, PubMed, and Google Scholar. We found that individual choices vary based on factors such as attitudes, trust, taste, texture, nutritional content, ethical considerations, and cultural influences. Nutritional factors, including protein content, amino acid profiles, and fat levels, significantly influence the preferences of bodybuilders and high-level meat consumers. However, it is crucial to maintain a balance by incorporating other essential nutrients such as carbohydrates, healthy fats, vitamins, and minerals to ensure a complete and balanced diet. The findings from this review can inform strategies and product development initiatives tailored to the needs of bodybuilders and discerning meat enthusiasts.

  • Bone healing under different lay‐up configuration of carbon fiber‐reinforced PEEK composite plates
    • Agnieszka Sabik
    2024 JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS

    Secondary healing of fractured bones requires an application of an appropriate fixa-tor. In general, steel or titanium devices are used mostly. However, in recent years,composite structures arise as an attractive alternative due to high strength to weightratio and other advantages like, for example, radiolucency. According to Food andDrug Administration (FDA), the only unidirectionally reinforced composite allowed tobe implanted in human bodies is carbon fiber (CF)-reinforced poly-ether-ether-ketone (PEEK). In this work, the healing process of long bone assembled withCF/PEEK plates with cross- and angle-ply lay-up configurations is studied in theframework of finite element method. The healing is simulated by making use of themechanoregulation model basing on the Prendergast theory. Cells transformation isdetermined by the octahedral shear strain and interstitial fluid velocity. The processruns iteratively assuming single load cycle each day. The fracture is subjected to axialand transverse forces. In the computations, the Abaqus program is used. It is shownthat the angle-ply lamination scheme of CF/PEEK composite seems to provide betterconditions for the transformation of the soft callus into the bone tissue.

  • Brewery spent grain valorization through fermentation: Targeting biohydrogen, carboxylic acids and methane production
    • Jacobo Pérez-Barragán
    • Cristina Martínez-Fraile
    • Raúl Muñoz
    • Guillermo Quijano
    • Rafael Maya-Yescas
    • Elizabeth León-Becerril
    • Roberto Castro Munoz
    • Octavio García-Depraect
    2024 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION

    This study investigated three different fermentation approaches to explore the potential for producing biohydrogen, carboxylic acids, and methane from hydrolysates of thermally dilute acid pretreated brewer's spent grains (BSG). Initially, the research focused on maximizing the volumetric hydrogen production rate (HPR) in the continuous dark fermentation (DF) of BSG hydrolysates by varying the hydraulic retention time (HRT). The highest HPR reported to date of 5.9 NL/L-d was achieved at 6 h HRT, with a Clostridium-dominated microbial community. The effect of the operational pH (4, 5, 6, and 7) on the continuous acidogenic fermentation was then investigated. A peak carboxylic acid concentration of 17.3 g CODequiv./L was recorded at pH 6, with an associated volumetric productivity of 900.5 ± 13.1 mg CODequiv./L-h and a degree of acidification of 68.3 %. Lactic acid bacteria such as Limosilactobacillus and Lactobacillus were dominant at pH 4–5, while Weissella, Enterococcus, and Lachnoclostridium appeared at pH 6 and 7. Finally, this study evaluated the biochemical methane potential of the DF broth and the unfermented hydrolysates and found high methane yields of 659 and 517 NmL CH4/g-VSadded, respectively, both within one week. Overall, the results showed that pretreated BSG can be a low-cost feedstock for the production of bioenergy and valuable bio-based chemicals in a circular economy.

  • Bridging the Gap Between Legitimacy and Neutralisation Strategies in Sustainability Reporting
    • Eljas Johansson
    2024

    Amid global sustainability challenges, such as climate change, companies operating in different industries face increasing demands for accountability and transparency. To meet these demands, sustainability reporting (SR) has become a mainstream business practice in communicating companies’ positive and negative sustainability impacts. This short paper aims to increase our understanding of how companies may release negative information while seeking to maintain their legitimacy. For this purpose, the paper bridges the gap between legitimacy strategies, impression management and neutralisation techniques by reviewing their associated literature. The nature of neutralisation techniques and how organisations use them in the SR context is underexplored by scholars. Finally, the paper presents prospective discussions of an ongoing study that examines negative sustainability disclosure in the tourism transportation context, namely the airlines.

  • Calculation of electron scattering lengths on Ar, Kr, Xe, Rn and Og atoms
    • Paweł Syty
    • Michał Piłat
    • Józef Sienkiewicz
    2024 JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

    Focusing on the noble gases, we calculate the scattering potential using the Dirac-Coulomb Hamiltonian supplemented with a model polarization potential. We determine the scattering lengths using two methods, namely phase shifts for very small scattering energies and the shape of the wave function for zero scattering energy. We compare our theoretical electron scattering length results on Ar, Kr and Xe atoms with existing experimental and theoretical data. In turn, the results obtained for the first time for Rn and Og atoms require independent confirmation. The analysis conducted indicates that the source of the greatest uncertainty in the obtained results is the literature values of dipole polarizability. The study used the GRASP2018 computational package for bound states and the modified COWF code for continuum states.

  • Can we really solve an arch stability problem?
    • Jacek Chróścielewski
    • Victor Eremeev
    2024 Pełny tekst INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We bring attention to the problem of solving nonlinear boundary-value problems for elastic structures such as arches and shells. Here we discuss a classical problem of a shear-deformable arch postbuckling. Considering a postbuckling behaviour of a circular arch we discuss the possibility to find numerically a solution for highly nonlinear regimes. The main attention is paid to the problem of determination of all solutions. The main conclusion that there is no guarantee to find all solutions, in general.

  • Carbon dioxide sequestration by industrial wastes through mineral carbonation: Current status and perspectives
    • Xiaodan Lin
    • Yingshuang Zhang
    • Hongwen Liu
    • Grzegorz Boczkaj
    • Yijun Cao
    • Chongqing Wang
    2024 JOURNAL OF CLEANER PRODUCTION

    Mineral carbonation using natural minerals or industrial wastes is a safe and promising strategy for CO2 sequestration. Application of industrial wastes for this purpose has significant ecological and environmental value, which is one of the key green technologies in the global carbon mitigation. This review summarizes the current research status of CO2 mineralization by industrial wastes. This work surveys the mechanisms and capacities of CO2 mineralization using different industrial wastes (mainly steel slags, blast furnace slags, coal fly ash, waste gypsum, and red mud), evaluates the influence of carbonation pathways and process parameters on the CO2 sequestration capacity, and analyzes the current industrial application status of CO2 sequestration using industrial wastes. Direct aqueous carbonation and indirect carbonation are the two most studied and promising mineralization routes. The leaching-mineralization cycle process has great potential for industrial application, especially for the treatment of coal fly ash, steel slag and other wastes containing calcium oxide, owing to the stable cycle performance of the absorbers. Researchers pay more attention to CO2 mineralization by steel slag compared to other wastes, and the capacity of CO2 mineralization varies greatly for different wastes. Several reports already reported carbonation effectiveness up to 100%. A CO2 sequestration capacity reached 536 g/kg for steel slag and 361 g/kg of blast furnace slag, revealing superior properties of these materials. CO2 sequestration using industrial wastes benefits CO2 emission reduction and comprehensive utilization of industrial wastes. To overcome the problem of the high energy consumption for regeneration of absorbent, a novel integrated CO2 absorption-mineralization process is currently widely studied. A possibility of co-production of value-added products - like different types of zeolite or lithium orthosilicate based adsorbents was highlighted, improving the economic balance of the overall process. More studies on pilot scale should be performed, to fully confirm the feasibility of developed technologies. Application of these developments is still faced with significant issues, including low carbonation efficiency, poor product quality, high process cost, and insufficient mass and heat transfer.

  • Carburization Behavior of High-Grade Pellets After Direct Reduction in Pure Hydrogen
    • Angelo Perrone
    • Pasquale Cavaliere
    • Behzad Sadeghi
    • Leandro Dijon
    • Aleksandra Mirowska
    • Damian Koszelow
    2024 Journal of Sustainable Metallurgy

    Carburization is a critical aspect in the iron and steel industry as it significantly affects the mechanical and chemical properties of the final product. This study provides a comprehensive analysis of the carburization potential of high-grade quality iron ore pellets after direct reduction in pure hydrogen. The results show that the porosity of the pellets has a significant impact on the efficiency and success of the direct reduction process with hydrogen. The reduction process can be completed at a lower temperature in pure hydrogen compared to carbon monoxide, with the iron carbide concentration peaking at temperatures up to 500 °C before decreasing with further temperature increases. The uniform distribution of SiO2, Al2O3, and CaO is critical to the carburizing process and affects the final properties of the steel. An increased degree of metallization and porosity are associated with an improved carburizing tendency. This study highlights the intricate interplay between temperature, carbon sources, and the resulting equilibrium concentration of iron carbides and provides insights into the complex dynamics of this phenomenon.

  • Cascaded Buck Hybrid Interlink Converter for Multiple-Input / Multiple-Output Operation
    • Ahmed Awadelseed
    • Arkadiusz Lewicki
    • Charles Odeh
    • Atif Iqbal
    2024 Pełny tekst

    The provision of isolated- and non-isolated DC output voltages by Power electronics power-conditioning devices in the recent ‘green-energy-revolution’ era is on course. In this paper, a structure for multi-input multi-output(MIMO) DC–DC buck converter is proposed to generate output voltages of varying levels with fewer component-count. The DC output voltage of each of the constituting buck converters can be used independently or cascaded with one another, depending on the output load voltage requirement. The converter operational modes are analysed and its gain models are derived. Also, expressions for the efficiency and power density of the proposed buck converter are presented. Distinct features of proposed converter are: its simplified configuration, high input/output power density, low-cost involvement, reduction of ripple amplitudes of the source currents, and possibility of deploying energy sources with different voltage-current characteristics. High voltage gain, and bidirectional power flow can be achieved in the converter operations. Experimental results on a laboratory prototype of the proposed MIMO validated the presented DC-DC buck converter topological concept

  • Catalysts for advanced oxidation processes: Deep eutectic solvents-assisted synthesis – A review
    • Amir Mohammad Sheikh Asadi
    • Łukasz Cichocki
    • Ali Atamaleki
    • Marjan Hashemi
    • Holger Lutze
    • Muhammad Imran
    • Lingshuai Kong
    • Chongqing Wang
    • Grzegorz Boczkaj
    2024 Pełny tekst Water Resources and Industry

    New catalyst synthesis techniques, including green materials, are extensively studied for heterogeneous photocatalytic advanced oxidation processes (AOPs) on spotlight of sustainable development. Deep eutectic solvents (DESs) started to be used in this field as environmentally friendly alternative to ionic liquids (ILs). During the catalyst synthesis, DESs can act as stabilizers, capping agents, structure directing agents, templates, hydrolyzing agents, etching agents, intercalators, and latent supramolecular catalysts. Importantly, DESs have exhibited the ability to significantly influence catalyst morphology, functionalization and photocatalytic properties (confirmed both for classic UV lamps and light emitting diode (LED)), including band-gap modification. DESs positive effect was proved for a variety of materials, including metal oxides, metalorganic (MO) complexes and doped materials, MXene (MAX phase etching in DES environment), inorganic-organic hybrids, carbo-catalysts. Substantial enhancements were obtained for modification of photocatalytic materials like TiO2, ZnO, MnO2, iron oxides, ceria oxides, CdS, bismuth based photocatalysts and biochar modification. In this aspect, a particular role of DESs was confirmed for synthesis of nanomaterials in a form of nanoparticles, nanopowders or nanosheets. Effectiveness was further increased by oxidants such as hydrogen peroxide, persulfates and Fenton process. Effective application of DES-modified catalysts was confirmed for degradation of dyes (Rhodamine B, Reactive orange 16, Safranine, Orange II, methylene blue), pharmaceuticals and antibiotics (Cefixime, Tetracycline, Oxytetracycline, Flumequine, Sulfamethaxazole), PFASs (Perfluorooctanoic acid) and Cr(VI). This reveals high potential of DES based photocatalysts for environmental engineering and remediation. There are still remaining a significant gaps in our understanding of the roles and impacts of DESs in AOPs. Furthermore, there is an absence of data regarding the recovery of DESs in the catalyst synthesis processes applied in AOPs. Addressing this aspects is vital for economic and environmentally friendly applications. As research progresses, it is essential to unravel the intricacies of DES-mediated catalyst synthesis and their broader consequences.

  • Catalytic activity of Ni-MgAl2O4 modified with transition metal (Ti, Mo, W) carbides as potential catalysts for resource recovery via dry reforming of waste plastics
    • Ewelina Pawelczyk
    • Izabela Wysocka
    • Tomasz Dymerski
    • Jacek Gębicki
    2024 Pełny tekst CATALYSIS TODAY

    The growing amounts of plastic waste and CO2 emissions are two environmental threats that require urgent attention. Pyrolysis combined with dry reforming (PCDR) is a technology that allows both CO2 utilization and resource recovery from waste plastic. New catalysts for PCDR are crucial for developing efficient and stable processes that can be widely implemented in the industry. In this study, Ni/MgAl2O4 catalysts modified using different transition metal (Ti, Mo, W) carbides were investigated in the PCDR of low-density polyethylene (LDPE) and polystyrene (PS) with emphasis on syngas yield, H2/CO ratio, product distribution, and catalyst deactivation. In addition, the effect of reforming temperature and process pressure was investigated. The catalysts were characterized using H2-TPR, CO2-TPD, N2 physisorption, XRD, TEM, XPS and TGA. The combined characterization and activity tests demonstrated that modification with different metal carbides affects the structure and activity of Ni/MgAl2O4 catalysts in relation to product yields, syngas composition, and catalyst stability. The investigation revealed that modification of nickel catalysts with different transition metal carbides enables manipulation of syngas composition, which is of great importance because different industrial processes require synthesis gas with different H2:CO ratios. Moreover, mixed outcomes were observed when different plastic feedstocks were used in the PCDR, indicating that different metal carbide-modified catalysts may be suitable for the process depending on the feedstock used. Regarding the effectiveness of synthesis gas production and catalyst stability, the most promising catalyst was the Ni-TiC/MgAl2O4 catalyst. According to the obtained results, modification with TiC resulted not only in increased synthesis gas production but also in reduced carbon deposition in PCDR of both LDPE and PS.

  • Catheter-induced coronary artery and aortic dissections. A study of the mechanisms, risk factors, and propagation causes
    • Jacek Klaudel
    • Michał Glaza
    • Barbara Klaudel
    • Wojciech Trenkner
    • Krzysztof Pawłowski
    • Marek Szołkiewicz
    2024 Pełny tekst Cardiology Journal

    Background: Only the incidence, management, and prognosis of catheter-induced coronary artery and aortic dissections have been systematically studied until now. We sought to evaluate their mechanisms, risk factors, and propagation causes. Methods: Electronic databases containing 76,104 procedures and complication registries from 2000– –2020 were searched and relevant cineangiographic studies adjudicated. Results: Ninety-six dissections were identified. The overall incidence was 0.126%, and 0.021% for aortic injuries. The in-hospital mortality rate was 4.2%, and 6.25% for aortic dissections. Compared to the non-complicated population, patients with dissection were more often female (48% vs. 34%, p = 0.004), with a higher prevalence of comorbidities such as hypertension (56% vs. 25%, p < 0.001) or chronic kidney disease (10% vs. 4%, p = 0.002). They more frequently presented with acute myocardial infarction (72% vs. 43%, p < 0.001), underwent percutaneous coronary intervention (85% vs. 39%, p < 0.001), and were examined with a radial approach (77% vs. 65%, p = 0.011). The most prevalent predisposing factor was small ostium diameter and/or atheroma. Deep intubation for support, catheter malalignment, and vessel prodding were the most frequent precipitating factors. Of the three dissec- tion mechanisms, ‘wedged contrast injection’ was the commonest (the exclusive mechanism of aortic dissections). The propagation rate was 30.2% and led to doubling of coronary occlusions and aortic extensions. The most frequent progression triggers were repeat injections and unchanged catheter. In 94% of cases, dissections were inflicted by high-volume operators, with ≥ 5-year experience in 84% of procedures. The annual dissection rate increased over a 21-year timespan. Conclusions: Catheter-induced dissection rarely came unheralded and typically occurred during ur- gent interventions performed in high-risk patients by experienced operators. (Cardiol J) Key words: catheter-induced coronary dissection, iatrogenic aortocoronary dissection, percutaneous coronary intervention complications

  • Celowe zanieczyszczanie pilotów w łączu w górę w interfejsie 5G NR
    • Jarosław Magiera
    • Piotr Rajchowski
    2024 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Referat poświęcono zagadnieniu zakłócania sygnałów pilotowych w interfejsie radiowym 5G NR. Przedstawiono charakterystykę sygnału referencyjnego DMRS oraz uwarunkowania możliwości jego selektywnego zakłócenia. Opisano schemat transmisji w kanale fizycznym PUSCH, zaimplementowany w oprogramowaniu Sionna. Zaprezen-towano model symulacyjny oraz założenia badań wpływu zanieczyszczenia pilotów na jakość transmisji. Przedsta-wiono wyniki badań w zależności od mocy źródła zakłóce-nia oraz od jego lokalizacji względem stacji bazowej.

  • Centrifuge modelling of tapered wall jacked into dense sand
    • Lech Bałachowski
    • Worku Firomsa Kabeta
    • Luc Thorel
    • Matthieu Blanc
    • Thierry Dubreucq
    2024

    A series of static penetration tests of trapezoidal walls in dense Fontainebleau sand were performed in the geotechnical centrifuge at Gustave Eiffel University. The models of wall with three different shapes (straight profile with thickness D=16mm, 0.75 degree and 1.5 degree of taper angle) but with the same volume were used. The soil mass was instrumented with five stress cells located at two levels at 2D, 4D and 6D distance from the wall axis to follow the stress state changes during the model penetration. Moreover, three pressure sensors were integrated on the model surface to track the changes of normal stress during the continuous penetration of the wall. Thus for the three walls of different geometry the evolution of the following variables is considered during monotonic penetration of the wall: 1) total vertical force; 2) horizontal stresses in the soil mass; 3) normal stresses on the wall surface.

  • CFD COUPLING OF VOF MODEL WITH ARRHENIUS EQUATION FOR ANALYSIS OF LASER-INDUCED THERMAL DEACTIVATION OF E. COLI
    • Aimad Koulali
    • Piotr Radomski
    • L. De Sio
    • Dariusz Mikielewicz
    • Paweł Ziółkowski
    2024 Pełny tekst

    Understanding bacterial deactivation at the micro-scale, particularly with E. coli, is crucial for advancing microbiology and has promising applications in biomedical research. In this research contribution, we investigate the thermal inactivation of E. coli bacteria using gold nanoparticles irradiated by a green 1-W laser within a microfluidic chamber. The microfluidic device comprises a fluidic chamber filled with a thin film of water and air (1 mm thick). The chamber is constructed with 1 mm PDMS coating on the top and side walls, and 1 mm borosilicate glass on the bottom. Computational Fluid Dynamics (CFD) calculations are executed using ANSYS Fluent software employing the Volume of Fluid (VOF) multi-phase model. Bacterial deactivation is described by a first-order kinetic model, while the Arrhenius equation is employed to define the decay coefficient. The light-heat conversion is modeled using a literature-based approach, validated against experimental data. Our findings affirm the efficacy of the proposed physical model (laser + gold nanoparticles) for bacterial inactivation. Additionally, we propose an innovative approach by coupling bacterial inactivation equations and VOF model, opening avenues for further applications in the field.

  • Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
    • Torkan Shafighfard
    • Farzin Kazemi
    • Faramarz Bagherzadeh
    • Magdalena Mieloszyk
    • Doo-Yeol Yoo
    2024 Pełny tekst COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING

    One of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was assessed based on 193 experimental specimens from real-life beam models. The ML techniques were applied to predict SFRC beam responses to bending load as functions of the steel fiber properties, concrete elastic modulus, beam dimensions, and reinforcement details. The accuracy of the models was evaluated using the coefficient of determination (R2), mean absolute error (MAE), and root mean square error (RMSE) of actual versus predicted values. The findings revealed that the proposed technique exhibited notably superior performance, delivering faster and more accurate predictions compared to both the ANNs and parallel models. Shapley diagrams were used to analyze variable contributions quantitatively. Shapley values show that the chained model prediction of ductility index is highly affected by two other targets (peak load and peak deflection) that show the chained algorithm utilizing the prediction of previous steps for enhancing the prediction of the target feature. The proposed model can be viewed as a function of significant input variables that permit the quick assessment of the likely performance of SFRC beams in bending.

  • Characteristics of silver-dopped carbon nanotube coating destined for medical applications
    • Dorota Rogala-Wielgus
    • Beata Majkowska-Marzec
    • Andrzej Zieliński
    2024 Pełny tekst Materials Today Communications

    Carbon nanotubes are materials demonstrating outstanding mechanical, chemical, and physical properties and are considered coatings of titanium implants. The present research is aimed to characterize the microstructure and properties of the multi-wall carbon nanotubes (MWCNTs) layer decorated with silver nanoparticles (Ag NPs) on the Ti13Nb13Zr alloy destined for long-term implants. The electrophoretic deposition of coatings was performed in a two-stage process, at first at 0.25 wt. pct. of MWCNTs, and next at 0.30 wt. pct. of Ag NPs content in the bath. The SEM, EDS, AFM, Raman spectroscopy, nanoindentation tests, nano-scratch test, wettability assessments, and corrosion tests were carried out. The effects of the presence of Ag NPs onto the MWCNTs coating were observed as the roughness increased to 0.380 µm and thickness to 5.26 µm, the improved adhesion and corrosion resistance, the water contact angle of 62.94◦, the decreased nanohardness, Young`s modulus and resistance to plastic deformation under load, and slightly improved adhesion. The obtained results can be explained by a specific two-layer structure of the coating, in which the Ag NPs agglomerates create the coating less porous and permeable, but softer structure. Future research will focus on the improvement of the adhesion of the component coatings in different ways.

  • Characterization of corrosion in reinforced concrete beams using destructive and non-destructive tests
    • Tomasz Ferenc
    • Erwin Wojtczak
    • Błażej Meronk
    • Magdalena Rucka
    2024 Pełny tekst Case Studies in Construction Materials

    The paper presents both non-destructive and destructive experimental tests on steel-reinforced concrete beams subjected to electrochemical corrosion. To examine the condition and behavior of the specimens, destructive tests were carried out, i.e., a three-point bending together with a modulated ultrasonic wave test. In addition, a series of non-destructive experiments were conducted, such as the potential measurement method, low-frequency vibrations, and ultrasonic wave propagation. A three-point bending test was conducted to examine the behavior of specimens under applied quasi-static force, together with a modulated ultrasonic wave test. The force-displacement relation, capacity, failure displacement, flexural stiffness, and failure mode were determined for each specimen. A modulated ultrasonic wave test was also performed during the flexural test. Prior to this, the specimens were visually inspected to check if any cracks occurred and a series of non-destructive tests such as potential measurement, low-frequency vibrations, and ultrasonic wave propagation were then performed.