2022 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2022

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Non-Adaptive Rotor Speed Estimation of Induction Machine in an Adaptive Full-Order Observer
- Marcin Morawiec
- Paweł Kroplewski
- Charles Ikechukwu Odeh
2022 Full text IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
In the sensorless control system of an induction machine, the rotor speed value is not measured but reconstructed by an observer structure. The rotor speed value can be reconstructed by the classical adaptive law with the integrator. The second approach, which is the main contribution of this paper, is the non-adaptive structure without an integrator. The proposed method of the rotor speed reconstruction is based on an algebraic relationship – the rank of the mathematical model of the observer system is not increased. However, the problem with the stabilization of the observer structure does exist. For near to zero rotor speed or in the regenerating mode of an induction machine, the speed observer structure can be unstable. Therefore, in this paper, the new stabilization functions are proposed. The stability is provided by the Lyapunov theorem and the practical stability theorems in which the uncertainty of parameters is considered. In the proposed solution, the newly introduced stabilization functions guarantee observer stability during both the motoring and regenerating conditions at the chosen low rotor speed ranges and for different load torque values. All the theoretical considerations were confirmed by simulation and experimental tests during the chosen working modes and uncertainties of nominal parameters of the induction machine.
Non-Adaptive Speed and Position Observer of Doubly-Fed Induction Generator
- Marcin Morawiec
- Krzysztof Blecharz
- Arkadiusz Lewicki
2022
The non-adaptive speed and position estimation of a doubly-fed induction generator (DFIG) is presented in this paper. The speed observer is based on the mathematical model of DFIG and to stabilize the structure the Lyapunov method is used. The classic stator field-oriented control to active and reactive power control is used in the sensorless control system. The performance of the proposed algorithm of a speed observer is validated by simulation and experimental results using the 2 kW generator. The stability analysis of the presented solution is confirmed by using the Lyapunov method and practical stability theorems.
Non-Contact Monitoring of ECG in the Home Environment—Selecting Optimal Electrode Configuration
- Adam Bujnowski
- Kamil Osiński
- Piotr Przystup
- Jerzy Wtorek
2022 Full text SENSORS
Capacitive electrocardiography (cECG) is most often used in wearable or embedded measurement systems. The latter is considered in the paper. An optimal electrocardiographic lead, as an individual feature, was determined based on model studies. It was defined as the possibly highest value of the R-wave amplitude measured on the back of the examined person. The lead configuration was also analyzed in terms of minimizing its susceptibility to creating motion artifacts. It was found that the direction of the optimal lead coincides with the electrical axis of the heart. Moreover, the electrodes should be placed in the areas preserving the greatest voltage and at the same time characterized by the lowest gradient of the potential. Experimental studies were conducted using the developed measurement system on a group of 14 people. The ratio of the R-wave amplitude (as measured on the back and chest, using optimal leads) was less than 1 while the SNR reached at least 20 dB. These parameters allowed for high-quality QRS complex detection with a PPV of 97%. For the “worst” configurations of the leads, the signals measured were practically uninterpretable.
Non-Contact Temperature Measurements Dataset
- Aleksander Mroziński
2022 Full text
The dataset titled The influence of the distance of the pyrometer from the surface of the radiating object on the accuracy of measurements contains temperature measurements using a selection of four commercially available pyrometers (CHY 314P, TM-F03B, TFA 31.1125 and AB-8855) as a function of the measuring distance. The dataset allows a comparison of the accuracy and measuring precision of the devices, which are very important features in the reliable non-contact prediction of COVID-19 symptoms without interference from external disturbances during fast patient recognition.
Nonconventional 1,8-Diazafluoren-9-One Aggregates for Green Light Enhancement in Hybrid Biocompatible Media
- Aneta Lewkowicz
- Mattia Pierpaoli
- Katarzyna Walczewska-Szewc
- Martyna Czarnomska
- Piotr Bojarski
- Robert Bogdanowicz
- Stanisław Pogorzelski
- Leszek Kułak
- Jakub Karczewski
2022 Full text Materials
Organic aggregates currently play a prominent role, mainly for their unique optoelectronic properties in the aggregated state. Such properties can be related to the aggregates’ structure and the molecular packing mode. In the literature, we have well-established models of H and J aggregates defined based on the molecular exciton model. However, unconventional aggregates, the most unrecognized forms, have been generating interest among researchers recently. Within unconventional aggregation, aggregation-induced emission systems (AIE) are considered. In the present work, we discuss the effect of the forming of unconventional aggregation together with the change in dye concentration on the surface energy characteristics of the materials. All materials were prepared as hybrid biocompatible thin films where the matrix is TiO2 or TiO2/carbon nanowalls (CNWs) with the incorporated dye in the form of 1,8-diazafluoren-9-one (DFO). Using the time-resolved emission spectra and the determination of surface parameters from contact angle measurements, we indicated the correlation between the changes in such parameters and the concentration of DFO dye in two types of TiO2 and TiO2/CNW structures. To examine the propensity of DFO for aggregation, the internal energy of the dye was assessed in several aggregate structures using Quantum chemistry calculations. The results emphasize that DFO is an attractive structure in the design of new fluorophores due to its low molecular weight, the presence of a nitrogen atom that provides good coordination properties, and the ability to form hydrogen bonds. Our studies show that when using suitable matrices, i.e., rigid media, it forms the preferred forms of aggregates in the excited state, characterized by high emission efficiency in the band maximum of around 550 nm.
Non-Isocyanate-Based Waterborne Polyurethanes
- Marcin Włoch
- Iga Carayon
2022
Non-isocyanate polyurethanes (NIPUs) are a greener alternative for the conventional polyurethanes synthesized using toxic and moisture-sensitive di- or polyisocyanates. The most often described method of NIPU synthesis involves the reaction of five-membered cyclic carbonates with amines, and resulting polymers containing primary and secondary hydroxyl groups (so they are also known as polyhydroxyurethanes), which can be further used for the functionalization of such macromolecules. What cannot be omitted is an application of bio-based substrates in the synthesis of NIPUs, which presently may constitute more than 50 wt.% of such NIPU systems. Waterborne non-isocyanate polyurethanes (WNIPUs) can be prepared as solids, solutions, or dispersions by several different synthetic pathways. Broad-spectrum synthesis methods and used compounds may lead to sufficient molecular masses and mechanical properties on a laboratory scale. Some semi-products of such reactions can be further processed into thin films, coatings, hydrogels, or functionalized nanoparticles. Thus, careful selection of substrates, as in the case of isocyanate-based polyurethanes, provides many opportunities for valuable product fabrication. WNIPUs in the form of dispersions may find an application to cast films with great success, whereas the formation of latexes allows for coating formation. Coatings are the largest group of proposed WNIPU applications due to excellent adhesion, gloss, mechanical properties (flexibility and impact resistance), and thermal stability. Hydrogels are just after coatings because they are characterized by favorable mechanical properties and swelling capability. In this chapter, we describe the synthesis and properties of WNIPUs.
Non-Least Square GNSS Positioning Algorithm for Densely Urbanized Areas
- Jerzy Demkowicz
2022 Full text Remote Sensing
The paper introduces an essentially new algorithm for calculating the GNSS position as an alternative to the least-square method. The proposed approach can be widely applied to any positioning method that uses multiple position lines for position calculation and is an example ofhow using a numerical solution can improve position accuracy without access to historical data. In essence, the method is based on the adaptation of the median filtering method widely used in the field of image processing, while at the same time applying a combinatorial approach and order statistics. The proposed solution makes it possible to improve on and assess the credibility of a single measurement. The article highlights the differences between the proposed and currently used approaches, as well as their advantages and disadvantages. The algorithm has been extensively tested under various environmental and weather conditions. The tests were carried out in typical and also in very demanding conditions, thus taking into account the real application context, i.e., pedestrian and car navigation in densely urbanized areas.
Non-Linear Analysis of Structures Utilizing Load-Discretization of Stiffness Matrix Method with Coordinate Update
- Najmadeen Saeed
- Ahmed Manguri
- Marcin Szczepański
- Robert Jankowski
2022 Full text Applied Sciences-Basel
This paper proposes a stiffness method based structural analysis algorithm for geometrically non-linear structures. In this study, the applied load on the joints has been discretized to a sequence of a few loadings applied. Each loading step produces incremental external nodal displacements, which are added to the corresponding coordinates to get a new geometrical shape of the structure. This process is iteratively repeated until the sum of the loading of all iterations matches the total initial applied loading. The size of the increments affects the technique’s accuracy, subsequently affecting the number of iterations. The configuration of non-linear geometrical structures is vital in the work; a slight change of the coordinates makes a considerable variation of nodal displacements. In this paper, three pin-jointed assemblies and a cantilever beam have been examined using the proposed technique; significantly reasonable outcomes emerged, compared to the non-linear approaches, such as Dynamic Relaxation Method (DRM) and Non-linear approach by Kwan. In a numerical sense, the dissimilarity between the results of the conventional Stiffness Matrix (SM) method and the non-linear method is about 228%, while the maximum discrepancy between the proposed approach and the non-linear methods is just above 15%
Nonlinear free and forced vibrations of a dielectric elastomer-based microcantilever for atomic force microscopy
- Amin Alibakhshi
- Shahriar Dastjerdi
- Mohammad Malikan
- Victor Eremeev
2022 Full text CONTINUUM MECHANICS AND THERMODYNAMICS
The majority of atomic force microcode (AFM) probes work based on piezoelectric actuation. However, some undesirable phenomena such as creep and hysteresis may appear in the piezoelectric actuators that limit their applications. This paper proposes a novel AFM probe based on dielectric elastomer actuators (DEAs). The DE is modeled via the use of a hyperelastic Cosserat model. Size effects and geometric nonlinearity are included utilizing the modified couple stress theory and the von-Kármán strains. A non-contact interaction condition is adopted for AFM, which is taken into account via the van der Waals force. Governing equations are derived employing Hamilton’s principle, and a reduced model is obtained using an extended Galerkin scheme. The free vibration of the system is formulated when a static voltage is applied to the elastomer. The forced vibration is then formulated when the system is under a combination of static and dynamic voltages. The ordinary differential equations of the free and forced vibrations are numerically and analytically solved by the backward differentiation method and multiple time scales method, respectively. Results are presented in time histories, phase portraits, Poincaré maps, fast Fourier transforms, and frequency amplitude curves. Overall, the obtained information displays that the system undergoes quasiperiodic and periodic motions. Moreover, the resonant response of the DE-based AFM is softening-type.
Nonlinear material identification of heterogeneous isogeometric Kirchhoff–Love shells
- Bartosz Borzeszkowski
- Izabela Lubowiecka
- Roger Sauer
2022 Full text COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
This work presents a Finite Element Model Updating inverse methodology for reconstructing heterogeneous materialdistributions based on an efficient isogeometric shell formulation. It uses nonlinear hyperelastic material models suitable fordescribing incompressible material behavior as well as initially curved shells. The material distribution is discretized by bilinearelements such that the nodal values are the design variables to be identified. Independent FE analysis and material discretization,as well as flexible incorporation of experimental data, offer high robustness and control. Three elementary test cases and oneapplication example, which exhibit large deformations and different challenges, are considered: uniaxial tension, pure bending,sheet inflation, and abdominal wall pressurization. Experiment-like results are generated from high-resolution simulations withthe subsequent addition of up to 4% noise. Local optimization based on the trust-region approach is used. The results showthat with a sufficient number of experimental measurements, design variables and analysis elements, the algorithm is capableto reconstruct material distributions with high precision even in the presence of large noise. The proposed formulation isvery general, facilitating its extension to other material models, optimization algorithms and meshing approaches. Adaptedmaterial discretizations allow for an efficient and accurate reconstruction of material discontinuities by avoiding overfitting dueto superfluous design variables. For increased computational efficiency, the analytical sensitivities and Jacobians are provided.
Nonlinear strain gradient and micromorphic one-dimensional elastic continua: Comparison through strong ellipticity conditions
- Victor Eremeev
- Emanuele Reccia
2022 Full text MECHANICS RESEARCH COMMUNICATIONS
We discuss the strong ellipticity (SE) conditions for strain gradient and micromorphic continua considering them as an enhancement of a simple nonlinearly elastic material called in the following primary material. Recently both models are widely used for description of material behavior of beam-lattice metamaterials which may possess various types of material instabilities. We analyze how a possible loss of SE results in the behavior of enhanced models. We shown that SE conditions for a micromorphic medium is more restrictive than for its gradient counterpart. On the other hand we see that a violation of SE for a primary material affects solutions within enhanced models even if the SE conditions are fulfilled for them.
NONLINEAR VIBRATION ANALYSIS OF BEAM AND PLATE WITH CLOSED CRACK: A REVIEW
- Samrawit Alemayehu Tewelde
- Marek Krawczuk
2022 Full text Acta Mechanica et Automatica
The effect of nonlinearity is high sensitivity in damage detection, especially for closed cracks and delamination. This review illustrates the results of several researchers dealing with nonlinear effects caused by the closure of cracks in the structure, i.e., beam and plate structures. Early detection of damage is an important aspect for the structure and, therefore, continuous progress is being made in developing new and effective methods that use nonlinear effects for early detection of damage and barely visible cracks, i.e., closed cracks and delamination, as well as for the determination of crack size and location. After analysing various methods, the merits, drawbacks and prospects of a number of nonlinear vibration methods for structural damage detection are discussed, and recommendations are made for future researchers
Nonlocal Models of Plates and Shells with Applications in Micro- and Nanomechanics
- Mohammad Malikan
2022 Full text
Nowadays, the use of small-scale structures in micro/nanomachines has become more and more widespread. The most important applications of such small-sized parts are in micro-electro-mechanical systems (MEMS) as well as nano-electro-mechanical systems (NEMS) as actuators, sensors, energy harvesters. For example, nanosensors are nanoscale devices that measure physical quantities and convert these to signals that can be detected and analyzed. On the applications of micro/nanosensors in civil engineering, one can state that nanosensors can be developed and used in construction to monitor and/or control the environmental conditions and the materials/structures' performance. As an example, nanosensors can be used to monitor concrete corrosion and micro-cracking. The smart sensor can also be employed for structural health monitoring in bridges and other structures. In this regard, understanding the mechanical response of such structures in various environmental and physical situations is seriously required. For the design and modelling of such a device, one can use various approaches. First, we mention straightforward experiments which need special equipment and result in high costs. Second, molecular dynamics could be used, which requires a lot of computational efforts, in general. Moreover, this method cannot be implemented for all types of nanostructures. Finally, the application of continuum models properly modified for modelling materials and structures at small scales is worth mentioning. Among various enhancements of classic mechanics of continua and structures, we mention the non-local approach related to the description of long-range interactions. In what follows, we apply the third technique based on non-local models and corresponding modelling to thin-walled structures as principal elements of MEMS and NEMS. Moreover, we consider the coupling between mechanical and electromagnetic fields. So this dissertation is based on this approach. Using it, the mechanical behavior of the MEMS and NEMS has been predicted.
Nonlocalized thermal behavior of rotating micromachined beams under dynamic and thermodynamic loads
- Ahmed E. Abouelregal
- Hamid M. Sedighi
- Mohammad Malikan
- Victor Eremeev
2022 Full text ZAMM-Zeitschrift fur Angewandte Mathematik und Mechanik
Rotating micromachined beams are one of the most practical devices with several applications from power generation to aerospace industries. Moreover, recent advances in micromachining technology have led to huge interests in fabricating miniature turbines, gyroscopes and microsensors thanks to their high quality/reliability performances. To this end, this article is organized to examine the axial dynamic reaction of a rotating thermoelastic nanobeam under a constant-velocity moving load. Using Eringen’s nonlocal elasticity in conjunction with Euler–Bernoulli theory and Hamilton's principle, the governing equations are derived. It is assumed that the nanobeam is affected by thermal load and the boundary condition is simply supported. The Laplace transform approach is employed to solve the partial differential equations. A numerical example is presented to analyze the effects of the nonlocal parameter, rotation speed and velocity of the static moving load on the dynamic behavior of the system. The numerical results are graphically illustrated and analyzed to recognize the variations of field variables. Finally, in some special cases, our results are compared to those reported in the literature to demonstrate the reliability of the current model.
Non-Perfect Propagation of Information to a Noisy Environment with Self-Evolution
- Piotr Mironowicz
- Paweł Horodecki
- Ryszard Horodecki
2022 Full text ENTROPY
We study the non-perfect propagation of information for evolving a low-dimensional environment that includes self-evolution as well as noisy initial states and analyse the interrelations between the degree of objectivization and environment parameters. In particular, we consider an analytical model of three interacting qubits and derive its objectivity parameters. The numerical analysis shows that the quality of the spectrum broadcast structure formed during the interaction may exhibit non-monotonicity both in the speed of self-dynamics of the environment as well as its mixedness. The former effect is particularly strong, showing that—considering part of the environment as a measurement apparatus—an increase of the external magnetic field acting on the environment may turn the vague measurement into close to ideal. The above effects suggest that quantum objectivity may appear after increasing the dynamics of the environment, although not with respect to the pointer basis, but some other, which we call the generalized pointer or indicator basis. Furthermore, it seems also that, when the objectivity is poor, it may be improved, at least by some amount, by increasing the thermal noise. We provide further evidence of this by analysing the upper bounds on distance to the set of states representing perfect objectivity in the case of a higher number of qubits.
Non-volatile molecular composition and discrimination of single grape white of chardonnay, riesling, sauvignon blanc and silvaner using untargeted GC–MS analysis
- Bekzod Khakimov
- Inal Bakhytkyzy
- Carsten Fauhl-Hassek,
- Søren Balling Engelsen
2022 FOOD CHEMISTRY
This study developed and applied a GC–MS method aiming at molecular fingerprinting of 120 commercial single grape white wines (Chardonnay, Riesling, Sauvignon Blanc and Silvaner) for possible authentication according to grape variety. The method allowed detection of 372 peaks and tentative identification of 146 metabolites including alcohols, organic acids, esters, amino acids and sugars. The grape variety effect explained 8.3% of the total metabolite variation. Univariate tests showed two-thirds of the metabolites being different between grape varieties. Partial least squares-discriminant analysis based classification models were developed for each grape variety and a panel of classifiers (42 metabolites) was established. All the classification models for grape variety showed a high certainty (>91%) for an independent test set. Riesling contained the highest relative concentrations of sugars and organic acids, while concentrations of hydroxytyrosol and gallic acid, common antioxidants in wine, decreased in the order of Chardonnay > Riesling > Sauvignon Blanc > Silvaner.
Notch fatigue analysis and life assessment using an energy field intensity approach in 7050-T6 aluminium alloy under bending-torsion loading
- Ricardo Branco
- José Domingos Costa
- L.p. Borrego
- Wojciech Macek
- Filippo Berto
2022 Full text INTERNATIONAL JOURNAL OF FATIGUE
This paper studies the fatigue crack initiation and fatigue crack propagation of notched cylindrical bars made of 7050-T6 aluminium alloy subjected to multiaxial bending-torsion loading. The sites of crack initiation and the angles of crack initiation were successfully predicted from the distribution of the first principal stress at the notch surface. Fatigue crack initiation lives were computed through the new concept of energy field intensity formalised in a linear-elastic framework along with a local stress-strain model for notch plasticity analysis. Regardless of the model used to compute the cyclic response at the geometric discontinuity, the fatigue life predictions were in good agreement with the experimental observations.
Novel amides of mycophenolic acid and some heterocyclic derivatives as immunosuppressive agents
- Juliusz Walczak
- Dorota Iwaszkiewicz-Grześ
- Michalina Ziomkowska
- Magdalena Śliwka-Kaszyńska
- Mateusz Daśko
- Piotr Trzonkowski
- Grzegorz Cholewiński
2022 Full text JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
The group of new amide derivatives of mycophenolic acid (MPA) and selected heterocyclic amines was synthesised as potential immunosuppressive agents functioning as inosine-5'-monophosphate dehydrogenase (IMPDH) uncompetitive inhibitors. The synthesis employed uronium-type activating system (TBTU/HOBt/DIPEA) while or phosphonic acid anhydride method (T3P/Py) facilitating amides to be obtained in moderate to excellent yields without the need of phenolic group protection. Most of optimised protocols did not require complicated reaction work-ups, including chromatographic, solvent- consuming methods. The biological activity assay was performed on the T-Jurkat cell line and peripheral mononuclear blood cells (PBMCs) which are both dedicated for antiproliferative activity determination. Each of designed derivatives was characterised by reduced cytotoxicity and benzoxazole analogue revealed the most promising activity. Subsequently, an observed structure-activity relationship was discussed.
Novel Binary Mixtures of Alkanolamine Based Deep Eutectic Solvents with Water—Thermodynamic Calculation and Correlation of Crucial Physicochemical Properties
- Bartosz Nowosielski
- Marzena Jamrógiewicz
- Justyna Łuczak
- Dorota Warmińska
2022 Full text MOLECULES
This paper demonstrates the assessment of physicochemical and thermodynamic properties of aqueous solutions of novel deep eutectic solvent (DES) built of tetrabutylammonium chloride and 3-amino-1-propanol or tetrabutylammonium bromide and 3-amino-1-propanol or 2-(methylamino)ethanol or 2-(butylamino)ethanol. Densities, speeds of sound, refractive indices, and viscosities for both pure and aqueous mixtures of DES were investigated over the entire range of compositions at atmospheric pressure and T = (293.15 - 313.15) K. It was concluded that the experimental data were successfully fitted using the Jouyban–Acree model with respect to the concentration. Obtained results showed that this mathematical equation is an accurate correlation for the prediction of aqueous DES properties. Key physicochemical properties of the mixtures—such as excess molar volumes, excess isentropic compressibilities, deviations in viscosity, and deviations in refractive indices—were calculated and correlated by the Redlich–Kister equation with temperaturedependent parameters. The non-ideal behavior of the studied systems were also evaluated by using the Prigogine−Flory−Patterson theory and the results were interpreted in terms of interactions between the mixture components.
Novel chalcone-derived pyrazoles as potential therapeutic agents for the treatment of non-small cell lung cancer
- Natalia Maciejewska
- Mateusz Olszewski
- Jakub Jurasz
- Marcin Serocki
- Maria Dzierżyńska
- Katarzyna Cekała
- Ewa Wieczerzak
- Maciej Bagiński
2022 Full text Scientific Reports
Lung cancer is considered to account for approximately one-fifth of all malignant tumor-related deaths worldwide and is therefore one of the most lethal malignancies. Pyrazole scaffold possesses a wide range of biological and pharmacological activities, which play important roles in medicinal chemistry. The present study reports the synthesis and in vitro biological characterization of nine pyrazoles derived from chalcones as potential anticancer agents for non-small cell lung cancer A-549, H226, and H460 cell lines. Most of the compounds efficiently inhibited the growth of all the tested cancer cell lines at micromolar concentrations. One of the most active compounds (PCH-1) was further evaluated for its effect on cell cycle distribution, apoptosis, migration, epithelial–mesenchymal transition, and oxidative stress. Furthermore, studies on the mechanism of action revealed that PCH-1 disrupts microtubule assembly, leading to cancer cell death. Molecular modeling studies confirmed the potent interaction of PCH-1 with the vinblastine binding site on tubulin. Overall, this study provides novel opportunities to identify anticancer agents in the pyrazole series.