2024 - Repozytorium publikacji - Politechnika Gdańska

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Experimental and numerical studies on the mechanical response of a piezoelectric nanocomposite-based functionally graded materials
- Mohammad Malikan
- Magdalena Rucka
2024
This work presents an experimental study of piezoelectric structures reinforced by graphene platelets, based on the concept of the functionally graded materials (FGMs). The assumed model is a rectangular beam/plate and the composition is due to the Halpin-Tsai rule. The model is also simulated in the Abaqus software which is the first time that such a structure has been modelled in an FEM package. In addition, a mathematical model based on a beam/plate theory, Lagrangian strains and variational technique is expressed and the derived partial differential equations governing the mechanics of the structure are solved numerically using the differential quadrature method. In terms of the experiments, the nanocomposite is fabricated in the form of layered FGMs using powder metallurgy. The specimens are subjected to two mechanical tests, bending and tensile. To accurately identify the FGM sample cross-section, a scanning electron microscope is used to examine the microstructure of the solid.
Experimental and numerical study of thermal and electrical potential of BIPV/T collector in the form of air-cooled photovoltaic roof tile
- Jakub Łukasik
- Jan Wajs
2024 Pełny tekst INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
Among renewable energy sources, Building-Integrated Photovoltaic/Thermal (BIPV/T) systems are gaining increasing interest. To improve their economic competitiveness, technologies that increase their efficiency are searched for. The paper is devoted to evaluating the impact of various air-cooling configurations on the thermal and electrical performance of a photovoltaic roof tile. A numerical model of the own experimental system was developed in the ANSYS Fluent software for a wide range of input variables. The original approach based on the SST k-ω turbulence model, Discrete Ordinates radiation model, and the use of Solar Load module were proposed. Such a numerical model allows representation of semi-transparent layers and variable solar irradiance, which is a unique realization of real system modelling. Numerous analyses conducted indicate a higher heat recovery potential for an airflow duct with a height of 25 mm for all configurations analysed. The highest value of recovered heat flux was approximately 330 W/m2 under conditions of a volumetric air flow rate of 7.5 m3/h and solar irradiance equal to 900 W/m2. Good agreement of the results of the multivariant CFD simulations with new experimental ones was confirmed. Insight into the flow phenomena behind the achieved thermal results supplemented the knowledge. The highest electrical efficiency obtained experimentally was 5.76 % for a channel with a height of 50 mm, volumetric flow rate equal to 7.5 m3/h and solar irradiance equal to 600 W/m2. The presented methodology and the results obtained can be useful in research devoted to optimising BIPV/T air-based cooling systems, which will then be tested in-situ. Moreover, new experimental data collection can be used for the verification of numerical models.
Experimental and numerical study on stability loss of innovative geometry steel girder
- Małgorzata Gordziej-Zagórowska
- Wojciech Migda
- Natalia Lasowicz
- Patryk Deniziak
- Alicja Bera
- Jakub Kowalski
2024 JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
This paper presents the experimental and numerical analysis of an innovative plate girder geometry with variable web thicknesses. An idea proposed in this research is to increase the stability of the girder web by increasing its thickness in the compressed zone. This solution can replace commonly used longitudinal stiffeners which are designed to prevent web local loss of stability. Moreover, such an innovative approach requires only one addi- tional butt weld along the entire element, which is technologically a simpler, cheaper and faster operation (due to the possibility of full automation of production) compared to manual welding of individual stiffeners. The experimental and numerical study shows that application of a web with variable thickness in I-shaped plate girder geometry subjected to four-point bending results in a change in failure mechanism from local to global one. Moreover plate girders with single and double-sided longitudinal stiffeners have been tested numerically. The result of the study clearly shows that values of ultimate load estimated for plate girders with longitudinal stiffeners were smaller than those obtained for innovative ones. It confirms that the proposed solution may prevent web from local stability loss and increase plate girder stability due to bending. This innovative method can be also considered as an effective procedure of strengthening the web in its compressive zone compared to commonly used longitudinal stiffeners
Experimental and theoretical study on high-temperature creep of VT6 titanium alloy under multi-axial loading conditions
- Leonid Igumnov
- Ivan Volkov
- V.a. Kazakov
- Denis Shishulin
- Ivan Modin
- Alexander Belov
- Victor Eremeev
2024 JOURNAL OF THERMAL STRESSES
In the framework of damage mechanics, we discuss a new mathematical model that describes the kinetics of the stress–strain state and damage accumulation during material degradation by the mechanism of long-term strength under complex multiaxial stress state. An experimental and theoretical technique is proposed for determination of material parameters and scalar constitutive functions for damaged media based on specially set experiments on laboratory specimens. The results of experimental studies and numerical simulations of short-term high-temperature creep of VT6 titanium alloy under uniaxial and multiaxial loading are presented. Numerical results are compared with the data obtained through experiments. Particular attention is paid to simulating the process of unsteady creep for complex deformation modes, accompanied by rotation of main areas of stress, strain and creep strain tensors. It is shown that the developed version of the constitutive relations of the damaged media enables us to describe the processes of unsteady creep and long-term strength of structural alloys under multiaxial stress with the accuracy sufficient for engineering calculations.
Experimental investigation of thermal energy storage in shell-and-multi-tube unit with nano-enhanced phase change material
- Maciej Fabrykiewicz
- Janusz Cieśliński
2024 APPLIED THERMAL ENGINEERING
This paper deals with thermal energy storage with use of nanoparticle enhanced phase change material in shell-and-multitube unit. The experiments are conducted under atmospheric pressure. Paraffin wax and two different fatty acids are used as base phase change material. Graphite and multi-walled carbon nanotubes serve as nanoparticles. Graphite nanoparticles are tested at the concentrations of 0.1%, 1% and 5% by weight, while multi-walled carbon nanotubes only at 0.1%wt. Ultrasonic vibration and homogenizer are used in order to stabilize the dispersion of the nanoparticles. Polyvinylpyrrolidone surfactant is used to stabilize the suspension and the tested nano-enhanced phase change material exhibit satisfactory stability. Experimental measurements are performed for a bundle of 7 tubes with outside diameter of 6 mm in a staggered arrangement and a pitch ratio of 4.5. It is found that, regardless of the tested base phase change material, the addition of graphite nanoparticles with mass concentration of 0.1% does not significantly affect the charging and discharging times compared to base phase change material. The differences in charging and discharging times did not exceed 11%. For a graphite nanoparticles mass concentration of 5%, an increase in the charging time by up to 21% and a reduction in the discharging time by 24% was observed, depending on the type of base phase change material. An addition of multi-walled carbon nanotubes with mass concentration of 0.1% shows an increase in charging time regardless of the type base phase change material up to 144% with negligible influence on the discharging time. It was also observed that adding a surfactant to the produced nano-enhanced phase change material results in a reduction in charging time by up to 83% depending on the type of base phase change material.
Experimental investigation on heat pipes supported by soy wax and lauric acid for electronics cooling
- Paweł Szymański
- Radosław Paluch
2024 Journal of Energy Storage
This paper presents an experimental study of heat pipes for electronics cooling that were supported by energy storage materials (i.e. phase change materials - PCMs) coated at the adiabatic section. The PCMs utilized included two materials, namely lauric acid and soy wax, the latter being considered as a more cost-effective alternative. The study focused on three different powers: 20 W, 25 W, and 30 W. Both heating, cooling, and thermal cycling experiments were performed in order to compare the thermal performance of cooling units. The experimental results showed that the incorporation of lauric acid as a thermal energy storage material reduced the maximum temperature by 11.6 %, 14.6 %, and 14.5 % for the examined powers. On the other hand, the utilization of soy wax resulted in temperature reductions of 4.3 %, 6.3 %, and 6.8 %. Furthermore, it was observed that lauric acid could store 25 % of the energy during the maximum power dissipation test, whereas soy wax could store 12 %. It was shown that lauric acid improved the thermal performance of the unit by approximately twice as effectively as soy wax. However, it is noteworthy that soy wax exhibits a significantly lower cost, making it a potentially viable alternative for less demanding applications where cost considerations are crucial.
Experimental investigations on water sorptivity in mortars with the use of X-ray micro-CT system.
- Łukasz Skarżyński
- Andrzej Tejchman-Konarzewski
2024 CONSTRUCTION AND BUILDING MATERIALS
W pracy doswiadczalnej zbadano zjawisko sorpcji wody w pryzmatycznych próbkach zapraw, które jest ściśle powiązane z trwałością materiału. Sorpcyjność oceniana na etapie ustalonym w połączeniu z warunkami zewnętrznymi może być wykorzystana do przewidywania okresu użytkowania. Sorpcyjność początkową i wtórną wody w próbkach zapraw nienasyconych zmierzono w badaniach laboratoryjnych zgodnie z normą amerykańską ASTM C 1585–04. Wpływ porowatości początkowej na sorpcyjność zbadano poprzez zmianę stosunku cementu do piasku (c/s) i stosunku wody do cementu (w/c). Dodatkowo zmieniono powierzchnię napływu wody, która miała orientację pionową lub poziomą. Nowością była wizualizacja rozkładu wody w badanych próbkach za pomocą aparatu rentgenowskiego mikro-CT 3D SkyScan 1173. Stwierdzono, że na sorpcyjność zaprawy silnie reaguje współczynnik c/s, wahający się do 100%, przy czym umiarkowany wpływ na nią ma współczynnik w/c zmieniający się aż do 25% i powierzchnia napływu wody zmienny od 25% do 45%. Sorpcyjność wzrastała wraz ze spadkiem współczynnika c/s (zgodnie z istniejącymi danymi literaturowymi) i stosunku w/c (w przeciwieństwie do istniejących danych literaturowych). Na podstawie zdjęć mikro-CT stwierdzono, że rozkład wody w próbkach zapraw był nierównomierny, a ich większa porowatość wpływała na wzrost poziomu wody, ale nie na całkowitą objętość pochłoniętej wody (w przeciwieństwie do danych literaturowych). Do odrywania cząstek wody doszło przed jej głównym frontem.
Experimental observations on the creep behaviour of frozen soil
- Katarzyna Staszewska
- Andrzej Niemunis
- Marcin Cudny
2024 Acta Geotechnica
Constitutive models in the literature for creep of frozen soil are based on the direct use of time counted from the onset of creep. An explicit time dependence in a constitutive equation violates the principles of rational mechanics. No change in stress or temperature is allowed for during creep, using the time-based formulations. Moreover, the existing descriptions need much verification and improvement on the experimental side as well. Creep behaviour of artificially frozen sand was evaluated experimentally. Novel testing methods were used, and new insights into the creep behaviour of frozen soil were gained. Creep rate under uniaxial compression was examined with different kinds of interruptions, like unloadings or overloadings. Experimental creep curves were presented as functions of creep strain. They were brought to a dimensionless form which describes the creep universally, despite changes in stress or temperature. Possible anisotropy of frozen soil was revealed in the creep tests on cubic samples with changes of the loading direction. Using the particle image velocimetry (PIV) technique, information on the lateral deformation and the uniformity of creep were obtained. Volumetric creep of unsaturated frozen soil under isotropic compression was demonstrated to be due to the presence of air bubbles only.
Experimental study and numerical simulation on porosity dependent direct reducibility of high-grade iron oxide pellets in hydrogen
- Behzad Sadeghi
- Pasquale Cavaliere
- Mutlucan Bayat
- Niloofar Ebrahimzadeh Esfahani
- Aleksandra Laska
- Damian Koszelow
2024 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
The transition to more environmentally friendly steel production methods has intensified research into hydrogen-based direct reduction (HyDR) of iron oxide pellets. The aim of this study is to systematically investigate the kinetics of the reduction process, the evolution of porosity and the resulting microstructural changes on the reduction behavior of high-quality pellets during HyDR of iron ore at different temperatures. A modified mathematical model is developed based on the shrinkage kernel model, taking into account both mass and heat transport in a hydrogen atmosphere. The effects of temperature, particle size and time on the reduction behavior of the pellets are investigated. The simulated results are validated and discussed by the results of a batch of iron oxide pellets consisting of ten almost spherical pellets subjected to the direct reduction process with pure hydrogen. The results show that the total energy input to the HyDR process is a complex balance of factors, including chemical reaction rates, diffusion dynamics and entropy generation. The increase in free volume and simultaneous decrease in pore diameter reflect the dynamic nature of the microstructure, which includes additional free volume and defects due to the volume discrepancies and associated stresses between the reactant and product phases. Furthermore, the data show that higher temperatures accelerate the reduction reactions, especially the transformation of wustite into metallic iron. This phase transition is characterized by a significant volume change that cannot be accommodated by elastic deformation alone, leading to the development of lattice defects such as cracks, creep pores and dislocations that serve as stress relief mechanisms. The trends for porosity change at 950 °C and 1000 °C observed in the experimental results are correct and in good agreement with the numerical and simulated results.
Experimental study of the impact of notches and holes made in the front edge of adherends on the properties of static and fatigue strength of adhesive joints
- Andrzej Kubit
- Wojciech Macek
- Władysław Zielecki
- Paulina Szawara
- Piotr Myśliwiec
2024 INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES
The paper presents the results of experimental studies aimed at determining the effect of holes and notches at the front edge of adherends on the strength of adhesive joints. Single-lap joints made of S235JR steel sheets joined with Araldite 2014-2 epoxy adhesive were tested. Comparative tests of static strength in the shear test as well as high-cycle fatigue strength tests were carried out. Joints with three holes with a diameter of 3 mm filled with adhesive and notches 3 mm wide and 4 mm long also filled with adhesive were tested and compared with reference joints, i.e. without modification. The assumption was that the structural changes applied were to contribute to the reduction of the peak of peel and shear stresses that typically occur in this type of joint. Based on the static strength tests, no significant effect of the applied modifications on the strength of the connections was demonstrated. However, in the case of fatigue strength, a significant improvement in fatigue lifetime was demonstrated, which in the area of low cycle fatigue increased by 328.6 % for the joint with notches and by 640.8 % for the variant with holes. For the fatigue fracture surfaces, a topography analysis was carried out by determining the roughness parameters. Significant differences were exposed since at the leading edge, the selected parameters were significantly lower for the reference variant than for variants with notches and holes.
Experimental study of the multi-disc negative brake for a hydraulic motor
- Paweł Śliwiński
- Ryszard Jasiński
2024
This paper describes the methodology for experimental testing of a multi-disc brake. The construction of this brake was also present. The brake is dedicated to hydraulic motors with a small working volume. Experimental tests were carried out on a brake with plates immersed in oil and, for comparison, tests were carried out on a dry brake. As a result of the tests, the permissible torque (load) that is able to transfer the brake and the pressure required to release the brake were determined. The temperature rise in the chamber of the uncoupled brake (both wet and dry brake), whose shaft with active discs was rotated at speed of 1,500 rpm, was also examined. The influence of the deformation of the brake discs on the characteristics of the torque of friction in these discs was also observed.
Experimental study on the feasibility of alternative materials for tilting pad thrust bearings operating in transition to mixed friction
- Michał Wasilczuk
- Michał Wodtke
2024 Pełny tekst Friction
In hydrodynamic bearings traditional bearing alloys: Babbitts and bronzes are most frequently utilized. Polymer sliding layers are sometimes applied as a valuable alternative. Hard diamond-like carbon (DLC) coatings, which are also considered for certain applications may show some advantages, as well. Although material selection is of secondary importance in a full film lubrication regime it becomes important in mixed friction conditions, which is crucial for bearings with frequent starts and stops. Experimental research aimed at studying the performance of fluid film bearings in the specific operating regime, including the transition to mixed friction, is described in the paper. The tests were carried out on four tilting pad bearings of different material compositions: Steel/bronze, DLC/steel, steel/polyether ether ketone (PEEK), and steel/Babbitt. The tests comprised stopping under load and reproduction of the Stribeck curve by decreasing rotational speed to very low values, and observing the changes of friction force during the transition to mixed friction regime. Analysis of the transition conditions and other results showed clear differences between the tested bearings, illustrating the feasibility of less popular material compositions for bearings operating in specific conditions. More specifically, the DLC/steel bearing was demonstrating superior performance, i.e. lower friction, transition to mixed friction occurring at higher load, and more stable performance at start-stop regime over the other tested bearings.
Experimental test results of an automatic voltage regulator with independent phase voltage controllers
- Wojciech Śleszyński
- Artur Cichowski
- Krzysztof Jakub Szwarc
- Robert Małkowski
- Paweł Szczepankowski
- Andrzej Augusiak
- Dariusz Karkosiński
- Ryszard Strzelecki
2024 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences
The growing number of distributed renewable energy sources and dynamic constant-power loads (e.g. electric vehicle charging stations) pose new challenges for network operators. These changes result in alterations to network load profiles and load flows, leading to greater voltage volatility. One effective solution to these problems can be the use of automatic voltage regulators (AVRs), which stabilize and symmetrize voltage output, whether at distribution transformers (DTs) or elsewhere in the distribution network. The device developed by the authors consists of two bidirectional power converters and three single-phase transformers connected in series to the low-voltage grid as a stabilizer. The proposed control system provides accurate and fast regulation of the AVR’s output voltage (within the range of ±10% of the nominal grid voltage), with each phase being independently adjusted, regardless of the type of power load. The article includes test results demonstrating selected functionalities of the developed AVR. The physical model of the device discussed in the article is a research componentof the LINTE2 laboratory of the Gda´nsk University of Technology
Experimental tests of steel double-type balcony connections
- Maciej Tomasz Solarczyk
- Paweł Michał Piotrkowski
- Maciej Niedostatkiewicz
2024 Pełny tekst Czasopismo Techniczne
The paper presents analysis and results of experimental tests of full scale prefabricated balcony sets with dimensions (width × length × height): 2.0 m × 2.78 m × 0.186 m (in slope to 0.17 m). The sets consists of reinforced concrete slabs (balcony and ceiling) connected with each other by double-type balcony connections. The paper analyses the impact of variable parameters on the load carry capacity of elements. Additionally an overview of current scientific and technical papers in the field of balcony connections is provided.
Experimentally Aided Operational Virtual Prototyping to Predict Best Clamping Conditions for Face Milling of Large-Size Structures
- Krzysztof Kaliński
- Marek Galewski
- Michał Mazur
- Natalia Stawicka-Morawska
2024 Applied Sciences-Basel
Vibrations occurring during milling operations are one of the main issues disturbing the pursuit of better efficiency of milling operations and product quality. Even in the case of a stable cutting process, vibration reduction is still an important goal. One of the possible solutions to obtain it is selection of the favorable conditions for clamping the workpiece to the machine table. In this paper, a method for predicting and selecting the clamping condition of a large-size workpiece for the reduction in vibrations during milling is presented. A modal test of the workpiece is performed first for a selected set of tightening screw settings. Next, one milling pass is performed to obtain reference data which are then used to tune the hybrid computational model. In the subsequent step, milling simulations are performed for a set of tightening variants, and the best one is selected, providing the lowest vibrations, assessed as the root mean square (RMS) of vibration displacements. In this paper, the description of the clamping selection procedure, key elements of the simulation model, and simulation and experimental results obtained for the milling of the test workpiece performed for a set of different clamping conditions are provided. The proposed method accurately predicts not only the best but also the worst clamping conditions.
Expermental investigation on adsorption of methylene blue dye from waste water using corncob cellulose-based hydrogel
- Samuel Latebo Majamo
- Temesgen Amibo
- Dereje Tadesse Mekonnen
2024 Pełny tekst Scientific Reports
Hydrogel from corncob cellulose was synthesized in this investigation. The synthesized Hydrogel was characterized by SEM, XRD, and FTIR instruments. As the results indicate the synthesized hydrogel has required and important features, these suggest the suitability of hydrogel for the adsorption of methylene blue dye (MBD). Three important process variables (dosage, contact time, and initial concentration) with three levels were studied during the adsorption process at 30 °C and neutral pH. The efficiency of hydrogel for adsorption of MBD was determined in each experiment. The experimental results were statistically analyzed and interpreted. The maximum removal efficiency was achieved at 2.22 g/L of dosage, 80.36 min of contact time, and 74.54 mg/L of initial concentration. At this condition, 98.25% of MBD was achieved through experimental tests. Kinetics, isotherm, and thermodynamics studies were performed. Langmuir isotherm is more suitable to describe the adsorption process and the Pseudo second-order kinetic model fits this process. From the thermodynamics studies, all negative values of change in Gibbs free energy (ΔG°), and positive value of change in enthalpy (ΔH°), and change in entropy (ΔS°) indicate that the carried out experimental process is a spontaneous and endothermic. Moreover, the regeneration experiment for adsorbent was performed. The treatment of real textile industry waste water was conducted and the removal efficiency of hydrogel was 64.76%. This removal percentage reduction from sythetic aqueous solution is due to involvement of other pollutants in the real waste water. The synthesized hydrogel adsorbent is suitable up to the third cycle without significant loss in removal efficiency.
Exploring avian exposure to parent polycyclic aromatic hydrocarbons (PAHs): Using the common eider Somateria mollissima in a global context
- Aneta Pacyna-Kuchta
- Juliana Souza-Kasprzyk
- Svend Erik Garbus
- Igor Eulaers
- Christian Sonne
- Dariusz Jakubas
2024 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
Compared to other organic contaminants, birds are rarely studied for their exposure to polycyclic aromatic hydrocarbons (PAHs), mainly due to their effective metabolization of parent PAHs. However, as some studies suggest, exposure to PAHs may result in adverse health effects including decreased survival, especially following oil spills. In the present study, we analyzed samples from a sea duck, the common eider Somateria mollissima including feathers, preen oil, blood, liver and bile, to evaluate whether non- lethally collected samples could be reliably used for avian biomonitoring strategies. Phenanthrene was the only individual PAH detected across sample types, with the highest concentration found in preen gland and the lowest in blood. Significant differences in concentrations were observed between bile vs preen gland and liver vs preen gland, while for most compounds neither blood nor feathers showed detectable levels of parent PAHs. Therefore, the utility of those sample types for PAH exposure assessment may be limited and should be interpreted with caution, moreover as several physiological factors may affect them. Additionally, we also provide a comparison with the available literature to review current avian PAH exposure assessment and outline future research focused needs.
Exploring Cause-and-Effect Relationships Between Public Company Press Releases and Their Stock Prices
- Filip Grzonkowski
- Paweł Weichbroth
2024
The aim of the work is to design and implement a method of exploring the cause-and-effect relationships between company announcements and the stock prices on NASDAQ stock exchange, followed by a brief discussion. For this purpose, it was necessary to download the stock quotes of selected companies from the NASDAQ market from public web sources. Additionally, media messages related to selected companies had to be downloaded, and then a news sentiment analysis mechanism had to be prepared. The mechanism of sentiment analysis was prepared based on the supervised machine learning approach. The implemented method was used to analyze the sentiment of a set of stock exchange announcements and it was correlated with changes in the share prices of selected companies. Based on the collected data, the association rules were extracted using the Apriori algorithm. While the obtained results are very promising, however, one should also estimate the rate of return for the interrelated transactions to determine the true and ultimate value of discovered relationships.
Exploring hydrogen energy systems: A comprehensive review of technologies, applications, prevailing trends, and associated challenges
- Muhammad Kamran
- Marek Turzyński
2024 Journal of Energy Storage
Exploring hydrogen energy and its associated technologies is a pivotal pathway towards achieving carbon neutrality. This article comprehensively reviews hydrogen production technologies, storage technologies, and end-use applications of hydrogen, based on the input energy source, operating conditions, conversion efficiency, energy density, and unit investment cost. The review also highlights the advantages, disadvantages, and technological readiness of hydrogen production technologies, and storage methods. The selected hydrogen production methods include pyrolysis, gasification, fermentation, biophotolysis, electrolysis, thermolysis, and photolysis, while the selected hydrogen storage technologies are compressed, liquid, cryo-compressed, adsorption, and hydrides. Water electrolysis, highly efficient at 55–80 % and versatile, comes with a higher cost of $4.15–$10.30/kg. In contrast, pyrolysis offers more cost-effective solutions with moderate efficiency (35–50 %) and a reasonable yield (25–65 g/kg), making it suitable for budget-sensitive projects. Compressed, liquid, and cryo-compressed hydrogen offer high efficiency with the added benefit of compact storage due to their high volumetric and gravimetric densities. Metal and chemical hydrides provide excellent safety and efficiency, with metal hydrides also delivering high volumetric density for more compact solutions. Furthermore, the review explores the applications of hydrogen energy in renewable energy systems, support to existing grid, transportation, cogeneration and tri-generation, and metallurgy along with insights from pilot projects. Moreover, the article examines the challenges and opportunities encountered in hydrogen production, storage methods, and end-use applications. Finally, the article conducts a SWOT analysis, pinpointing key aspects crucial for the successful adoption of hydrogen in the future. The conclusions indicate that ongoing efforts in performance enhancement, scaling up, and technical advancements are essential to establish a cost-effective hydrogen economy.
Exploring Mechanism of Corrosion Inhibition of WE43 and AZ31 Alloys by Aqueous Molybdate in Hank’s Solution by Multisine Impedimetric Monitoring
- Maria Osipenko
- Jakub Karczewski
- Michał Dominów
- Marta Prześniak-Welenc
- Jacek Gurgul
- Irina Kurilo
- Jacek Ryl
- Dmitry Kharitonov
2024 CORROSION SCIENCE
The concept of utilizing multisine dynamic electrochemical impedance spectroscopy to monitor effectiveness of a model molybdate inhibitor for AZ31 and WE43 Mg alloys is proposed. The corrosion kinetics and instantaneous values of inhibition efficiency (IE) of molybdate at concentrations up to 150 mM were examined. The inhibitor provides inhibition in Hank’s solution at concentrations starting from ca. 25 mM, with the IE of about 90%. These data together with results of the surface analysis allowed to propose the mechanism of the corrosion inhibition of AZ31 and WE43 Mg alloys by aqueous molybdate in Hank’s solution.