2022 - Repozytorium publikacji - Politechnika Gdańska

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Explicit solvent repulsive scaling replica exchange molecular dynamics ( RS‐REMD ) in molecular modeling of protein‐glycosaminoglycan complexes
- Mateusz Marcisz
- Margrethe Gaardløs
- Krzysztof Bojarski
- Till Siebenmorgen
- Martin Zachariasen
- Sergey A. Samsonov
2022 JOURNAL OF COMPUTATIONAL CHEMISTRY
Glycosaminoglcyans (GAGs), linear anionic periodic polysaccharides, are crucial for many biologically relevant functions in the extracellular matrix. By interacting with proteins GAGs mediate processes such as cancer development, cell proliferation and the onset of neurodegenerative diseases. Despite this eminent importance of GAGs, they still represent a limited focus for the computational community in comparison to other classes of biomolecules. Therefore, there is a lack of modeling tools designed specifically for docking GAGs. One has to rely on existing docking software developed mostly for small drug molecules substantially differing from GAGs in their basic physico-chemical properties. In this study, we present an updated protocol for docking GAGs based on the Repulsive Scaling Replica Exchange Molecular Dynamics (RS-REMD) that includes explicit solvent description. The use of this water model improved docking performance both in terms of its accuracy and speed. This method represents a significant computational progress in GAG-related research.
Exploring the Reactivity of Unsymmetrical Diphosphanes toward Heterocumulenes: Access to Phosphanyl and Phosphoryl Derivatives of Amides, Imines, and Iminoamides
- Natalia Szynkiewicz
- Jarosław Chojnacki
- Rafał Grubba
2022 Pełny tekst INORGANIC CHEMISTRY
We present a comprehensive study on the diphosphanation of iso(thio)cyanates by unsymmetrical diphosphanes. The reactions involving unsymmetrical diphosphanes and phenyl isocyanate or phenyl thioisocyanate gave rise to phosphanyl, phosphoryl, and thiophosphoryl derivatives of amides, imines, and iminoamides. The structures of the diphosphanation products were confirmed through NMR spectroscopy, IR spectroscopy, and single-crystal X-ray diffraction. We showed that unsymmetrical diphosphanes could be used as building blocks to synthesize phosphorus analogues of important classes of organic molecules. The described transformations provided a new methodology for the synthesis of organophosphorus compounds bearing phosphanyl, phosphoryl, or thiophosphoryl functional groups. Moreover, theoretical studies on diphosphanation reactions explained the influence of the steric and electronic properties of the parent diphosphanes on the structures of the diphosphanation products.
Extended micropolar approach within the framework of 3M theories and variations thereof
- Elena Vilchevskaya
- Wolfgang Müller
- Victor Eremeev
2022 Pełny tekst CONTINUUM MECHANICS AND THERMODYNAMICS
As part of his groundbreaking work on generalized continuum mechanics, Eringen proposed what he called 3M theories, namely the concept of micromorphic, microstretch, and micropolar materials modeling. The micromorphic approach provides the most general framework for a continuum with translational and (internal) rotational degrees of freedom (DOF), whilst the rotational DOFs of micromorphic and micropolar continua are subjected to more and more constraints. More recently, an “extended” micropolar theory has been presented by one of the authors: Eringen’s 3M theories were children of solid mechanics based on the concept of the indestructible material particle. Extended micropolar theory was formulated both ways for material systems as well as in spatial description, which is useful when describing fluid matter. The latter opens the possibility to model situations and materials with a continuum point that on the microscale consists no longer of the same elementary units during a physical process. The difference culminates in an equation for the microinertia tensor, which is no longer a kinematic identity. Rather it contains a new continuum field, namely an independent production term and, consequently, establishes a new constitutive quantity. This makes it possible to describe processes of structural change, which are difficult if not impossible to be captured within the material particle model. This paper compares the various theories and points out their communalities as well as their differences.
Extreme weather layer method for implementation of nature-based solutions for climate adaptation: Case study Słupsk
- Karolina Fitobór
- Rafał Ulańczyk
- Katarzyna Kołecka
- Klara Ramm
- Iwona Włodarek
- Piotr Zima
- Dominika Kalinowska
- Paweł Wielgat
- Małgorzata Mikulska
- Danuta Antończyk
- Krzysztof Krzaczkowski
- Remigiusz Łyszyk
- Magdalena Gajewska
2022 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
One of the most severe climate risks that is expected to affect all regions is related to stormwater. Climate models, constructed based on long-term trends, show that extreme weather events such as storms, cloudbursts and a large rise in sea level will be significant in the coming decades. Moreover, even the frequency and intensity of “normal” rainfall events, such as microbursts, are expected to be remarkably higher than today in some regions. The efficiency of urban drainage systems is affected by the land use in its whole catchment. In addition to the climate stress, there is ongoing continuous densification of urban space, resulting in more buildings and larger areas being covered with impervious surfaces. Planning decisions today approving such compaction do not consider the impacts beyond the close proximity of the land parcel. As a result, by following the current planning practices, cities are becoming extremely vulnerable to stormwater flooding (flash floods). This study presents a holistic and dynamic planning method – the Extreme Weather Layer (EWL) – that makes it possible to analyse the impact of a single development (e.g. paving a gravel parking lot with asphalt or turning an area of urban greenery into a shopping centre) on the performance of the urban drainage system and therefore on the flooding risk of the whole catchment. The EWL is based on a widely accepted drainage modelling engine coupled with GIS system and other databases which provide spatial information. Thus, the EWL combined with the systemic approach of turning from grey to green infrastructure could be a smart tool for implementing NBS solutions for stormwater management in climate adaptation in urban areas. This smart tool could indicate how much more green infrastructure is needed and which places in the city the mitigative NBS measures would help significantly.
Eye-tracking everywhere - software supporting disabled people in interaction with computers
- Klaudia Solska
- Tomasz Kocejko
2022
In this paper we present comprehensive system for communication with computer by gaze. One of the main assumptions behind this work was to provide solution that can be used with standard RGB webcam. The proposed comprehensive system included the eye tracking module and user interface for convenient gaze interaction with computer. As a result a fully functional application was developed. The average accuracy of the eye tracking module was 4.1°while precision was 0.042°.
Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
- Łukasz Breńkacz
- Paweł Bagiński
- Marek Adamowicz
- Sebastian Giziewski
2022 Pełny tekst Eksploatacja i Niezawodność - Maintenance and Reliability
Due to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate the influence of higher harmonics of supply voltage and current on the formation of torque oscillations on the shaft and excessive losses in the form of heat, a voltage source inverter with high switching silicon carbide (SiC) power transistors characterizing high precision of the output voltage generation with a fundamental harmonic frequency of several kilohertz has been used. During the first start-ups, it turned out that the system was not stable, and a failure occurred. The paper presents the consequences that may arise when a machine operating at a speed of about 70,000 rpm fails. The article contains pictures of a generator failure that occurred at a high rotational speed.
Family Tree for Aqueous Organic Redox Couples for Redox Flow Battery Electrolytes: A Conceptual Review
- Peter Fischer
- Petr Mazur
- Joanna Krakowiak
2022 Pełny tekst MOLECULES
Redox flow batteries (RFBs) are an increasingly attractive option for renewable energy storage, thus providing flexibility for the supply of electrical energy. In recent years, research in this type of battery storage has been shifted from metal-ion based electrolytes to soluble organic redox-active compounds. Aqueous-based organic electrolytes are considered as more promising electrolytes to achieve “green”, safe, and low-cost energy storage. Many organic compounds and their derivatives have recently been intensively examined for application to redox flow batteries. This work presents an up-to-date overview of the redox organic compound groups tested for application in aqueous RFB. In the initial part, the most relevant requirements for technical electrolytes are described and discussed. The importance of supporting electrolytes selection, the limits for the aqueous system, and potential synthetic strategies for redox molecules are highlighted. The different organic redox couples described in the literature are grouped in a “family tree” for organic redox couples. This article is designed to be an introduction to the field of organic redox flow batteries and aims to provide an overview of current achievements as well as helping synthetic chemists to understand the basic concepts of the technical requirements for next-generation energy storage materials.
Fast Design Optimization of Waveguide Filters Applying Shape Deformation Techniques
- Michał Baranowski
- Łukasz Balewski
- Adam Lamęcki
- Michał Mrozowski
2022 Pełny tekst
This paper presents an efficient design of microwave filters by means of geometry optimization using shape deformation techniques. This design procedure allows for modelling complex 3D geometries which can be fabricated by additive manufacturing (AM). Shape deforming operations are based on radial basis function (RBF) interpolation and are integrated into an electromagnetic field simulator based on the 3D finiteelement method (FEM). The optimization controls two sets of design variables, i.e. the geometrical parameters of the structure and the parameters that determine the shape deformation. This approach provides great design flexibility at marginal additional cost since shape deformations require very little computational effort. A complete design procedure of a Ku-band RX waveguide bandpass filter is shown to verify this approach. The designed filter is fabricated with selective laser melting (SLM) technology. Measurements are presented in comparison with simulation
Fast EM-Driven Parameter Tuning of Microwave Circuits with Sparse Sensitivity Updates via Principal Directions
- Anna Pietrenko-Dąbrowska
- Mateusz Kozieł
2022 KNOWLEDGE-BASED SYSTEMS
Numerical optimization has become more important than ever in the design of microwave components and systems, primarily as a consequence of increasing performance demands and growing complexity of the circuits. As the parameter tuning is more and more often executed using full-wave electromagnetic (EM) models, the CPU cost of the overall process tends to be excessive even for local optimization. Some ways of alleviating these issues exist, yet, they are limited either by their accessibility or applicability range. This work presents a novel algorithmic approach to accelerated gradient-based parameter tuning of microwave components with numerical derivatives. In our methodology, computational savings are achieved by exploiting the problem-specific knowledge, specifically, by restricting the gradient updates to an orthonormal basis of essential directions corresponding to the maximum variability of the circuit responses within the frequency bands of interest. The said directions are selected through an automated decision-making process involving the analysis of the circuit response variability. Our approach is demonstrated using two multi-parameter microwave devices. Comprehensive comparison with the benchmark methods, including the standard trust-region algorithm and the three accelerated versions, indicate savings of up to fifty percent associated only with minor reduction of the design quality.
Fast Real-Time RDFT- and GDFT-Based Direct Fault Diagnosis of Induction Motor Drive
- Piotr Kołodziejek
- Daniel Wachowiak
2022 Pełny tekst ENERGIES
This paper presents the theoretical analysis and experimental veriﬁcation of a direct fault harmonic identiﬁcation approach in a converter-fed electric drive for automated diagnosis purposes. On the basis of the analytical model of the proposed real-time direct fault diagnosis, the fault-related harmonic component is calculated using recursive DFT (RDFT) and Goertzel DFT (GDFT), applied instead of the full spectrum calculations required in the most popular FFT algorithm. The simulation model of an inverter sensorlessly controlled induction motor drive is linked with the induction machine rotor fault model for testing the sensitivity of the GDFT- and RDFT-based fault diagnosis to state variable estimation errors. According to the presented simulation results, the accuracy of the direct identiﬁcation of a fault-related harmonic is sensitive to the quality of fault harmonic frequency estimation. The sensitivity analysis with respect to RDFT and GDFT algorithms is included. Based on the experimental setup with a sensorlessly controlled induction motor drive with the investigated rotor fault, fault diagnosis algorithms were implemented in the microprocessor by integration with the control system in one microcontroller and experimentally veriﬁed. The RDFT and GDFT approach has shown accurate and fast direct automated fault identiﬁcation at a signiﬁcantly decreased number of arithmetical operations in the microcontroller, which is convenient for the frequency-domain fault diagnosis in electric drives and supports fault-tolerant control system implementation.
Fast-SEC coupled to ICP-MS for selected metal determination and its stability over time in polish wine
- Magdalena Fabjanowicz
- Justyna Płotka-Wasylka
2022 Pełny tekst MONATSHEFTE FUR CHEMIE
Metal ions contribute to the wine browning (as reaction catalysts), turbidity (in complexes), and astringency (due to inter- action with tannins). Being aware that bioavailability and metabolism of metal ions in the human body are strictly related with their concentration and the form they occur it is important to monitor not only the total content of metals but also their speciation. Thus, we can obtain more information about their potential toxicity to human health. Present research shows the application of fast size exclusion chromatography (Fast-SEC) coupled to ICP-MS for the evaluation of the distribution of elements in different sized complexes in Polish wine. The study was focused on the selected ten elements (Al, B, Ba, Cu, Fe, Mn, Ni, Pb, Sr, Zn). Additional information of this work was the evaluation of the metal complex stability over time. Based on the obtained results, it can be seen that metal complexes present in the studied wine samples are stable even 10 months after the wine bottle opening.
Fatigue Bending of V-Notched Cold-Sprayed FeCoCrNiMn Coatings
- Pasquale Cavaliere
- Angelo Perrone
- Alessio Silvello
- Aleksandra Laska
- Gianni Blasi
- Irene G. Cano
2022 Pełny tekst Metals
Cold-spray coatings were produced by FeCoCrNiMn high-entropy alloy powders deposited on carbon steel substrate. The coatings were realized at intermediate temperature and high pressure (at 1100 °C and 7 MPa). The coating microstructure was characterized by scanning electron microscopy and X-ray diffraction, revealing a very dense deposition and high flattening ratio of the splatted particles. This had a large influence on the strong adhesion of the mcoating to the substrate. The hardness and residual stress profiles were measured through nanoindentation and X-ray diffraction from the peak broadening measured layer by layer. The cyclic behavior of the coatings was evaluated through three-point bending tests performed on V-notched samples coated via cold spray. Cyclic tests were performed at different maximum strokes from 0.3 to 3.6 mm in order to monitor the crack initiation and propagation during bending tests. The fracture surface aspect was analyzed by scanning electron microscopy in order to reveal the fracture mechanisms in different deformation conditions.
Fatigue fracture morphology of AISI H13 steel obtained by additive manufacturing
- Wojciech Macek
- Rui F. Martins
- Ricardo Branco
- Zbigniew Marciniak
- Mirosław Szala
- Sebastian Wroński
2022 Pełny tekst INTERNATIONAL JOURNAL OF FRACTURE
The paper focuses on researching the effect of fatigue loading on metallic structure, lifetime, and fracture surface topographies in AISI H13 steel specimens obtained by selective laser melting (SLM). The topography of the fracture surfaces was measured over their entire area, according to the entire total area method, with an optical three-dimensional surface measurement system. The fatigue results of the SLM 3D printed steel specimens were compared with those reported for conventionally manufactured 13H steel. The investigation also considers the roughness of the specimens’ side surface. Moreover, the fractographic evaluation conducted using scanning electron microscopy confirms that the predominant fracture mechanism is transgranular fracture. Microtomography done after mechanical loading also showed the influence of the stress level on the porosity distribution. Both fractographic and Micro-CT investigations confirm that higher stresses result in coarser and much more uniform porosity observed in fractured samples. These comprehensive quantitative and qualitative fracture analyses are beneficial to predict the failure conditions of SLM steel parts, especially in the case of fatigue damage. From the quantitative analysis of the H13 SLM-manufactured fracture surface topography, it was possible to conclude that the larger the loadings acting on the specimen, the rougher the fracture surface because the ductile fracture mode dominates. It has also been proven that the porosity degree changes along the length of the sample for the most stressed specimens.
Fatigue fracture surface metrology of thin-walled tubular austenitic steel specimens after asynchronous loadings
- Wojciech Macek
- Łukasz Pejkowski
- Ricardo Branco
- Reza Masoudi Nejad
- Krzysztof Żak
2022 Pełny tekst ENGINEERING FAILURE ANALYSIS
This paper aims to study the effect of asynchronous axial-torsional strain-controlled loading histories on fracture surface behavior of thin-walled tubular X5CrNi18-10 (304/304L) austenitic steel specimens. Tests under pure axial loading and pure torsional loading are also conducted to better segregate the effect of multiaxiality. The fractures surface topographies were examined through the profiles over the entire surface with the support of an optical measurement system. Then, features of the post-failure fractures were related to the loading conditions and the fatigue life. The outcomes indicate that the multiaxial loading path significantly affects the surface topography. Overall, fracture surface parameters increase for higher fatigue lives. Based on the dialectic relationship, a fatigue damage model able to estimate the fatigue lifetime under asynchronous axial-torsional loading histories has been successfully developed. The fracture surface topology parameters collected from both sides of the same specimen lead to comparable results which reinforces the applicability of the proposed approach.
Fatigue life improvement using low transformation temperature weld material with measurement of residual stress
- Jordan Franks
- Greg Wheatley
- Pedram Zamani
- Reza Masoudi Nejad
- Wojciech Macek
- Ricardo Branco
- Farzaneh Samadi
2022 Pełny tekst INTERNATIONAL JOURNAL OF FATIGUE
Welding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial loading considering two types of LTT materials. The results show that the crack propagation of all samples was similar in cycles although both LTT materials extended the crack initiation, and, therefore, the overall life of the part. It was found that both LTT materials reduced the residual tensile stresses, increased the residual compressive stresses, leading to increase in fatigue life about 30%.
Fatigue of titanium alloy Ti6Al4V with diamond structure obtained by Laser Power Bed Fusion method
- Anna Falkowska
- Andrzej Seweryn
2022 Pełny tekst INTERNATIONAL JOURNAL OF FATIGUE
This paper presents the results of fatigue tests conducted on Ti6Al4V titanium alloy with diamond structure obtained by the Laser Power Bed Fusion method. Samples used in tests were printed with porosities: 81%, 73%, 50%, 34% and near-zero porosity. Samples were subjected to cyclic tests with a constant stress amplitude. The number of cycles until sample failure was registered. Obtained fatigue test results made it possible to determine simple, semi-empirical dependencies making it possible to forecast the fatigue life of Ti6Al4V titanium alloy with diamond structure obtained by the Laser Power Bed Fusion method under conditions of uniaxial, cyclically variable loads. The experimental results revealed that the initiation of the macro-crack occurred already with a small number of cycles. This was caused by the presence of two types of notches: technological micro-notches between particles of melted powder and notches related to the shape of the diamond structure itself. Microscopic observations of the fatigue fractures of samples were carried out, both on those subjected to low-cycle tests and those subjected to high-cycle tests. This made it possible to identify crack initiation and damage accumulation mechanisms as well as to propose numerical dependencies for samples of the tested structure. For this purpose, it is necessary to determine only the tensile strength of the given metamaterial and the fatigue characteristic for the given porosity.
Fault-tolerant performance of the novel five-phase doubly-fed induction generator
- Roland Ryndzionek
- Krzysztof Blecharz
- Filip Kutt
- Michał Michna
- Grzegorz Kostro
2022 Pełny tekst IEEE Access
The article presents the concept of a new design of a multi-phase doubly-fed induction generator (DFIG). The innovative design approach uses a five-phase power supply from the rotor side of the generator with a three-phase classic stator power supply. Modern three-phase doubly-fed induction generators are the dominant choice for Wind Energy Conversion Systems (WECS). Solutions of this type are sensitive to the loss of at least one phase of the power supply from the rotor side due to the failure of the rotor side inverter. The proposed design solution in the form of a multi-phase power supply in the rotor circuit aims to extend the range of possible failure-free operation of the generator system, thus reducing system downtime due to the failure of power electronic systems. The correctness of the adopted conceptual assumptions was confirmed by the results of laboratory tests. The main contribution is to prove that using five-phase rotor winding improves the overall reliability of the proposed electrical energy generation system significantly.
Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
- Corey E. Frank
- Emma E. McCabe
- Fabio Orlandi
- Pascal Manuel
- Xiaoyan Tan
- Zheng Deng
- Changqing Jin
- Mark Croft
- Thomas Emge
- Shukai Yu
- Huaiyu Wang
- Venkatraman Gopalan
- Saul Lapidus
- MeiXia Wu
- Man-Rong Li
- Juliane Gross
- Paul Burger
- Aleksandra Mielewczyk-Gryń
- Tomasz Klimczuk
- Weiwei Xie
- David Walker
- Martha Greenblatt
2022 CHEMISTRY OF MATERIALS
Three new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize as noncentrosymmetric R3c. Microprobe measurements indicate that for x = 0.25 and 0.5, the substitution of Sn4+ is not offset by vacancies, which implies the presence of Fe2+, as corroborated by X-ray absorption near-edge spectroscopy and single-crystal X-ray structure refinements. Neutron powder diffraction experiments on x = 0.5 indicate that these compounds are canted A-type antiferromagnets that, like Fe2O3 and InFeO3, consist of ferromagnetic layers that stack antiferromagnetically with a single magnetic transition. Weak ferromagnetic interactions persist to very high temperatures. Temperature-dependent second harmonic generation (SHG) measurements on x = 0.25 and 0.5 show a SHG response with ferroelectric-like hysteretic maxima that correspond with the respective magnetic transitions, which suggest coupling of the magnetic and polarization order. These new compounds provide more information about fine-tuning the electronic, magnetic, and structural properties of corundum-derived mutlferroics in the search for tunable high-temperature magnetoelectric materials.
Feature extraction in detection and recognition of graphical objects
- Jerzy Dembski
2022
Detection and recognition of graphic objects in images are of great and growing importance in many areas, such as medical and industrial diagnostics, control systems in automation and robotics, or various types of security systems, including biometric security systems related to the recognition of the face or iris of the eye. In addition, there are all systems that facilitate the personal life of the blind people, visually impaired or people in full health, but who need devices to support them in the increasingly complex modern world, such as home monitoring systems or driving assistance systems.
Feature Weighted Attention-Bidirectional Long Short Term Memory Model for Change Detection in Remote Sensing Images
- Raj Kumar Patra
- Sujata N. Patil
- Przemysław Falkowski-Gilski
- Zbigniew Łubniewski
- Rachana Poongodan
2022 Pełny tekst Remote Sensing
In remote sensing images, change detection (CD) is required in many applications, such as: resource management, urban expansion research, land management, and disaster assessment. Various deep learning-based methods were applied to satellite image analysis for change detection, yet many of them have limitations, including the overfitting problem. This research proposes the Feature Weighted Attention (FWA) in Bidirectional Long Short-Term Memory (BiLSTM) method to reduce the overfitting problem and increase the performance of classification in change detection applications. Additionally, data usage and accuracy in remote sensing activities, particularly CD, can be significantly improved by a large number of training models based on BiLSTM. Normalization techniques are applied to input images in order to enhance the quality and reduce the difference in pixel value. The AlexNet and VGG16 models were used to extract useful features from the normalized images. The extracted features were then applied to the FWA-BiLSTM model, to give more weight to the unique features and increase the efficiency of classification. The attention layer selects the unique features that help to distinguish the changes in the remote sensing images. From the experimental results, it was clearly shown that the proposed FWA-BiLSTM model achieved better performance in terms of precision (93.43%), recall (93.16%), and overall accuracy (99.26%), when compared with the existing Difference-enhancement Dense-attention Convolutional Neural Network (DDCNN) model.