2021 - Repozytorium publikacji - Politechnika Gdańska

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Flood Classification in a Natural Wetland for Early Spring Conditions Using Various Polarimetric SAR Methods
- Tomasz Berezowski
- Monika Gierszewska
- Tomasz Bieliński
2021 Pełny tekst
Abstract--- One of the major limitations of remote sensing flood detection is the presence of vegetation. Our study focuses on a flood classification using Radarsat-2 Quad-Pol data in a natural floodplain during leafless, dry vegetation (early spring) state. We conducted a supervised classification of a data set composed of nine polarimetric decompositions and Shannon entropy followed by the predictors' importance estimation to reveal which decomposed component had the strongest effect on classification models. Also, we tested two variants of polarimetric speckle filtering to see if this step influences the results. The classification accuracy was 0.78 and 0.83 for the boxcar and improved Lee sigma filter respectively. The Cloude - Pottier decomposition produced the highest accuracy (0.67) in a single-decomposition scenario, but the volume component of Pauli decomposition was the most important for classification in a multi-decomposition scenario.
Flow cytometric approach to evaluate the impact of hydro-technical concrete compounds’ release to the freshwater microbiome
- Barbara Wojtasik
- Małgorzata Zbawicka
- Lucyna Grabarczyk
- Wojciech Juzwa
2021 Pełny tekst ENVIRONMENTAL MONITORING AND ASSESSMENT
The aim of this research was to test the potential of applying a flow cytometric procedure to evaluate the impact of concrete compounds’ release to the freshwater microbiome. Cells from the collected samples were stained with a fluorogenic redox indicator dye that measures the redox potential of microbial cells. This novel approach was combined with the assessment of microorganisms’ penetration into the internal structures of concrete using the Rose Bengal sodium salt staining. Rose Bengal staining revealed an intense fouling of the upper and side walls of the concrete cubes and also indicated the penetration of microorganisms inside the concrete as observed for the cubes’ cross-sections. Flow cytometric cellular redox potential measurement revealed high percentages of active cells within the concrete’s porous structures and in non-exposed water (32.7% and 30.2% of active cells) versus samples from exposed water and concrete’s outer surfaces (6.8%, 6.1%, and 3.3% of active cells). The results demonstrated a detrimental impact of hydro-technical concrete on the vitality of microbial cells within the freshwater environment. Tested protocol by analyzing the physiology of microbial cells improved the functional description of complex communities to evaluate the fate of contaminants present in the concrete-based hydro-technical infrastructure.
Flow Process Models for Pipeline Diagnosis
- Zdzisław Kowalczuk
- Marek Tatara
2021
This chapter examines the problem of modeling and parameterization of the transmission pipeline flow process. First, the base model for discrete time is presented, which is a reference for other developed models. Then, the diagonal approximation (AMDA) method is proposed, in which the tridiagonal sub-matrices of the recombination matrix are approximated by their diagonal counterparts, which allows for a simple determination of the explicit form of the inverse matrix. Another suggestion is the Thomas model (ATM), in which the basic model is reformulated to a form to which the Thomas algorithm applies, at which the computational complexity of the order O(N) can be obtained. The fourth suggestion is a steady state analytical model (AMSS), characterizing the steady state after transient processes. In addition, the parameterization of the discrete models in space and time is analyzed, proposing a method ensuring the maximum margin of numerical stability. This model is verified by means of simulation tests. Finally, the developed model is compared with the basic model, taking into account the accuracy and time of calculations.
Fluorine ions in photocatalysts’ synthesis: an obstacle or an ally? The investigation of photocatalysts in Ti-O-F system
- Marta Kowalkińska
- Szymon Dudziak
- Jakub Karczewski
- Agnieszka Fiszka Borzyszkowska
- Anna Zielińska-Jurek
2021 Pełny tekst
Titanium(IV) oxide (TiO2) is one of the most promising photocatalysts, which is expected to be applied in the photocatalytic degradation of xenobiotics. For sustainable development and green chemistry approach recently, much effort has been paid to enhance TiO2 photocatalytic activity in UV-vis light by modifying its structure. The photocatalytic process’s complexity cannot be simply described as electron-hole pairs generations and •OH formation; therefore, the interaction between the surface structure of photocatalyst and reactant molecules needs further investigation. The surface chemistry and morphology of TiO2 are crucial factors that can affect its photocatalytic performance by influencing the selective adsorption and photocatalytic oxidation of substrates. In this regard, considering the strong complexation between F- and Ti and the high electronegativity of fluorine, the present study focused on Ti-O-F photocatalytic system. An advantage of introducing fluorine compounds inside the reaction system is the stabilization of thermodynamically unfavoured {0 0 1} facets, which are described as more active than other TiO2 facets with defined morphology. The obtained results for anatase nanosheets with exposed {0 0 1} facets have shown that a higher amount of surface fluorine enhances the photocatalytic degradation of phenol and its mineralization. This observation can be explained by F atoms influencing the surface charge distribution and raising charge separation in the 2D structure of TiO2. Meanwhile, samples with a lower F/Ti ratio on the surface and the presence of Ti3+ exhibited lower photocatalytic activity. On the other hand, titanium oxyfluoride (TiOF2) used as a precursor for the synthesis of 2D TiO2 had a negative effect on phenol photocatalytic degradation and TOC mineralization. In this case, fluorine ions could induce the surface formation of nonstoichiometric TiO2−x, which decreased photocatalytic activity of TiO2 particles with exposed {0 0 1} facets.
Focus on Misinformation: Improving Medical Experts’ Efficiency of Misinformation Detection
- Aleksandra Nabożny
- Bartłomiej Balcerzak
- Mikołaj Morzy
- Adam Wierzbicki
2021
Fighting medical disinformation in the era of the global pandemic is an increasingly important problem. As of today, automatic systems for assessing the credibility of medical information do not offer sufficient precision to be used without human supervision, and the involvement of medical expert annotators is required. Thus, our work aims to optimize the utilization of medical experts’ time. We use the dataset of sentences taken from online lay medical articles. We propose a general framework for filtering medical statements that do not need to be manually verified by medical experts. The results show the gain in fact-checking performance of expert annotators on capturing misinformation by the factor of 2.2 on average. In other words, our framework allows medical experts to fact-check and identify over two times more non-credible medical statements in a given time interval without applying any changes to the annotation flow.
Folding‐upon‐repair DNA nanoswitches for monitoring DNA repair enzymes activity
- Nada Farag
- Rosanna Mattossovich
- Rosa Merlo
- Łukasz Nierzwicki
- Giulia Palermo
- Alessandro Porchetta
- Giuseppe Perugino
- Francesco Ricci
2021 ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
We demonstrate here a new class of DNA‐based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding‐upon‐repair DNA nanoswitches are synthetic DNA sequences containing O6‐methyl‐guanine (O6‐MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation of the O6‐MeG nucleobases they can form stable intramolecular Hoogsteen interactions and fold into an optically active triplex DNA structure. We have first characterized the folding mechanism induced by the enzymatic repair activity through fluorescent experiments and Molecular Dynamics simulations. We then demonstrated that the folding‐upon‐repair DNA nanoswitches are suitable and specific substrates for different methyltransferase enzymes including the human homologue (hMGMT) and they allow the screening of novel potential methyltransferase inhibitors.
Food Bioactive Ingredients Processing Using Membrane Distillation
- Emilia Gontarek-Castro
- Marek Lieder
2021
Separation processes are an important part of today’s food industries, especially in the case of specific bioactive components due to their health benefits. In general, processing of bioactive food ingredients assumes the introduction of integrated system directed to their separation, fractionation, and recovery. Recently, membrane distillation (MD) has been considered as an alternative membrane-based separation and concentration process in food technology. MD separates volatile components from aqueous feed solution into the permeate through microporous hydrophobic membranes, by means of the vapor pressure difference on both membrane sides. This chapter contains the analysis of the ongoing literature related to recovery and purification of food bioactive compounds using membrane distillation. Insights into the use of different MD configurations have been discussed and typical advantages and drawbacks over conventional technologies and other membrane processes have been highlighted.
Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector
- Tomasz Stefański
- Jacek Gulgowski
2021 Pełny tekst ENTROPY
In this paper, the formulation of time-fractional (TF) electrodynamics is derived based on the Riemann-Silberstein (RS) vector. With the use of this vector and fractional-order derivatives, one can write TF Maxwell’s equations in a compact form, which allows for modelling of energy dissipation and dynamics of electromagnetic systems with memory. Therefore, we formulate TF Maxwell’s equations using the RS vector and analyse their properties from the point of view of classical electrodynamics, i.e., energy and momentum conservation, reciprocity, causality. Afterwards, we derive classical solutions for wave-propagation problems, assuming helical, spherical, and cylindrical symmetries of solutions. The results are supported by numerical simulations and their analysis. Discussion of relations between the TF Schrödinger equation and TF electrodynamics is included as well.
Fourth industrial revolution and new challenges in post-pandemic world
- Kazimierz Kosmowski
2021
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Fractal dimension for bending–torsion fatigue fracture characterisation
- Wojciech Macek
- Ricardo Branco
- Mateusz Korpyś
- Tadeusz Łagoda
2021 Pełny tekst MEASUREMENT
Fracture surfaces after biaxial fatigue tests were compared using fractal dimension for three types of metallic materials in smooth and notched specimens made of S355J2 and 10HNAP steels and 2017-T4 aluminium alloy, considering both proportional and nonproportional cyclic loading. High-resolution optical 3D measurement studies were performed on the entire fracture surface. A direct correlation between fractal dimension and fatigue loading was established. This systematic relationship can serve as a basis for obtaining information about fatigue loading from the fracture surfaces of failed materials and structures. Moreover, measurements of the fracture surface with an optical profilometer, quantitative analysis, and fractography contribute to a better comprehension of the fatigue failure processes. Differences in individual zones of fatigue fractures were identified while demonstrating the correctness of the total fracture surface method.
Fracture Areas Quantitative Investigating of Bending-Torsion Fatigued Low-Alloy High-Strength Steel
- Wojciech Macek
2021 Pełny tekst Metals
In this study, the impact of pseudo-random non-proportional bending-torsion fatigue loadings proportion on the fatigue life and the fracture surface topography was analyzed. Investigation was carried out for 24 specimens made of S355J2 steel with 11 different ratios of maximum stresses λ. For these cases, after the fatigue tests, the surface topography measurements were carried out using an optical profilometer, using the focus variation method. Three fracture zones were analyzed for each specimen: (1) total; (2) propagation; (3) rupture, taking into account the root average square height Sq and void volume Vv parameters. The results pointed that ratio of maximum stresses λ is the most influenced on volume surface parameters represented by void volume at a given height Vv, in the rupture area. A new fatigue loading parameter P was used, depending on fatigue life T and ratio of maximum stresses λ, which shows very good correlation in 4th degree type of fit, to void volume Vv parameter for the rupture area.
Free Convection Heat Transfer from Horizontal Cylinders
- Janusz Cieśliński
- Sławomir Smoleń
- Dorota Sawicka
2021 Pełny tekst ENERGIES
The results of experimental investigation of free convection heat transfer in a rectangular container are presented. The ability of the commonly accepted correlation equations to reproduce present experimental data was tested as well. It was assumed that the examined geometry fulfils the requirement of no-interaction between heated cylinder and bounded surfaces. In order to check this assumption recently published correlation equations that jointly describe the dependence of the average Nusselt number on Rayleigh number and confinement ratios were examined. As a heat source served electrically heated horizontal tube immersed in an ambient fluid. Experiments were performed with pure ethylene glycol (EG), distilled water (W), and a mixture of EG and water at 50%/50% by volume. A set of empirical correlation equations for the prediction of Nu numbers for Rayleigh number range 3.6 × 104 < Ra< 9.2 × 105 or 3.6 × 105 < Raq <14.8 × 106 and Pr number range 4.5 ≤ Pr ≤ 160 has been developed. The proposed correlation equations are based on two characteristic lengths, i.e., cylinder diameter and boundary layer length.
Freehand drawing versus digital design tools in architectural teaching
- Antoni Taraszkiewicz
2021 Pełny tekst Global Journal of Engineering Education
The oldest drawings resembling modern architectural designs date from the 22nd Century BC. Throughout history, the first drawings have evolved into the basic tool of the architect’s work. The exchange of information between the architect and the contractor began to take place through a drawing system, allowing to describe three-dimensional space using flat representations. With time, architectural drawings also began to resemble true works of art, delighting with their artistry and ability to show even the most complicated spatial and technical solutions. With the increasing use of digital design tools taking place today, the teaching and practical use of freehand drawing and traditional methods of presenting students’ work is beginning to disappear in architecture schools. The purpose of this article is to investigate students’ ability to use traditional and digital methods to create and present architectural designs, based on architectural education carried out in the Faculty of Engineering at Gdańsk University of Technology (FA-GUT), Poland, in the academic year 2020/2021.
Free-standing TiO2 nanotubes decorated with spherical nickel nanoparticles as a cost-efficient electrocatalyst for oxygen evolution reaction
- Łukasz Haryński
- Katarzyna Grochowska
- Jakub Karczewski
- Jacek Ryl
- Jakub Rysz
- Siuzdak Katarzyna
2021 Pełny tekst RSC Advances
Here, we report significant activity towards the oxygen evolution reaction (OER) of spherical nickel nanoparticles (NPs) electrodeposited onto free-standing TiO2 nanotubes (TNT) via cyclic voltammetry. It has been shown that simple manipulation of processing parameters, including scan rate and number of cycles, allows for formation of the NPs in various diameters and amounts. The polarization data with respect to transmission electron microscopy (TEM) allowed for determination of the diameter and propagation depth of the Ni NPs leading to the highest activity towards the OER with an overpotential of 540 mV at +10 mA cm−2 and Tafel slope of 52 mV per decade. X-ray photoelectron spectroscopy (XPS) indicates the presence of structure defects within Ni NPs whereas Mott–Schottky analysis provides information on the anodically shifted flat band potential and highly increased donor density. The obtained results along with literature studies allowed a proposal of the origin of the enhancement towards the OER. We believe that combination of transition metal-based NPs and TNT provides valuable insight on efficient and low-cost electrocatalysts.
Freeze-Up Ice Jam Formation in the River Bend, a Case Study on the Inner Mongolia Reach of Yellow River
- Shui-Xia Zhao
- Wen-Jun Wang
- Xiao-Hong Shi
- Sheng-Nan Zhao
- Ying-Jie Wu
- Qiang Quan
- Chao Lin
- Michał Szydłowski
- Wei Li
- Tomasz Kolerski
2021 Pełny tekst Crystals
Concern has been expressed regarding the impacts of climate change on river ice and ice jam formation in cold regions. Ice jams are easily initiated in bends and narrow channels and cause disasters. In this study, observations and remote sensing monitoring are used to study the freeze-up ice jam formation of bends. Sediment transport and freezing process of the river interact, influencing bed changes profile and sedimentary budget. River ice processes, channel evolution, ice hydro-thermodynamics, and ice jam accumulation are explored. The results show that the channel topography determines the river thalweg, and that the channel elevation interacts with the river ice through sediment transport. The channel shrinkage increases the probability of ice jam, and the sharp bend is prone to ice jam formation. Under the effect of secondary circulation flow in the bend and in the outer bank, the juxtaposed freeze-up and the hummocky ice cover occur in the same location, and frazil ice accumulates under the junction of the main channel and the shoals. Affected by the increase of the hydraulic slope and the velocity downstream, open water reaches develops downstream of the ice accumulation. An open water section is emerged upstream of the bend, due to the ice deposition, and partly cut-off supply of the frazil.
Frequency-Based Regularization for Improved Reliability Optimization of Antenna Structures
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
- Muath Al-hasan
2021 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
The paper proposes a modified formulation of antenna parameter tuning problem. The main ingredient of the presented approach is a frequency-based regularization. It allows for smoothening the functional landscape of the assumed cost function, defined to encode the prescribed design specifications. The regularization is implemented as a special penalty term complementing the primary objective and enforcing the alignment of the antenna responses with the target operating frequency (or frequencies for multi-band antennas). The result is an improved reliability and reduced cost of the optimization process, both highly desirable from the point of view of the efficacy of EM-driven design procedures. Furthermore, regularization makes the use of local routines sufficient even in situations where global search is otherwise imperative (e.g., due to poor initial design). Our methodology is demonstrated using three microstrip antennas. The superior performance of the approach, both in terms of design reliability and in terms of the computational cost of the optimization process, is corroborated by comparisons with a conventional formulation.
From Regenerative Buildings to Regenerative Urban Projects: Design frameworks to scale up within the area of regenerative practice
- Eduardo Blanco
- Dorota Kamrowska-Załuska
- Jonas Gremmelspacher
- Melinda Orova
2021
In this chapter, a discussion will be presented of design frameworks and assessment tools that are useful for boosting the scale jumping of regenerative design practices and the paradigm shift. Our main objectives will be to identify existing design and assessment frameworks, to describe the way they work and how they can contribute to scale-jumping regenerative design, as well as to identify shortcomings and opportunities. We showcase and discuss ten design frameworks that practitioners can use to foster regenerative projects on an urban scale.
From Structure to Luminescent Properties of B2O3-Bi2O3-SrF2 Glass and Glass-Ceramics Doped with Eu3+ Ions
- Karolina Milewska
- Michał Maciejewski
- Anna Synak
- Marcin Łapiński
- Aleksandra Mielewczyk-Gryń
- Wojciech Sadowski
- Barbara Kościelska
2021 Pełny tekst Materials
Glass-ceramics with the composition B2O3 -Bi2O3 -SrF2 were synthesized by the conventional melt-quenching technique and subsequent crystallization of the parental glasses. The temperature at which the ceramization was carried out was selected based on differential scanning calorimetry (DSC) analysis. The structure of the studied materials and the formation of SrF2 nanocrystals were confirmed by the Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques. It was found that the amount of strontium fluoride introduced into the parental borate-bismuth glass has a significant impact on the growth of SrF2 nanocrystals. In particular, the influence of the crystalline SrF2 phase on luminescence intensity and kinetics was studied using Eu2O3 -doped samples. An increase in luminescence intensity was observed in the samples in which SrF2 nanocrystals were formed. This is most likely related to the fact that some of the Eu3+ ions were (after annealing of the glass) located in the crystalline structure of strontium fluoride. This was confirmed both by the luminescence lifetime obtained based on the luminescence decay curves and the calculated Judd–Ofelt parameters, Ω2 and Ω4 . The results achieved confirm that the glasses and glass-ceramics described in this work could be considered as a new phosphor for light-emitting diodes (LEDs).
Fully Automated AI-powered Contactless Cough Detection based on Pixel Value Dynamics Occurring within Facial Regions
- Maciej Szankin
- Alicja Kwaśniewska
- Natalia Głowacka
- Jacek Rumiński
- Rey Nicolas
- David Gamba
2021
Increased interest in non-contact evaluation of the health state has led to higher expectations for delivering automated and reliable solutions that can be conveniently used during daily activities. Although some solutions for cough detection exist, they suffer from a series of limitations. Some of them rely on gesture or body pose recognition, which might not be possible in cases of occlusions, closer camera distances or impediments that prevent users from performing such movements at all. Others focus on analyzing breath using audio recordings, which cannot be easily applied in crowded or loud spaces. Many of them utilize visible light data which is prone to changing lighting conditions and can lead to various privacy concerns. Taking these into account, we propose to make use of the temporal pixel value changes occurring within specific facial areas. Due to the use of a combination of object detection and signal classification models, our system allows for fully automated classification of breathing anomalies. The benchmark evaluation performed on the newly created thermal cough data set proved the reliability of the introduced solution (precision of cough detection equals 94%). Due to the use of a lightweight deep learning model, the proposed system also has huge practical value, as it can potentially be deployed on edge devices frequently sought out in markets such as autonomous vehicles, drones, smart home or military applications.
Functional Safety and Cybersecurity Analysis and Management in Smart Manufacturing Systems
- Kazimierz Kosmowski
2021
This chapter addresses some of the issues of the integrated functional safety and cybersecurity analysis and management with regard to selected references and the functional safety standards: IEC 61508, IEC 61511, ISO 13849-1 and IEC 62061, and a cybersecurity standard IEC 62443 that concerns the industrial automation and control systems. The objective is to mitigate the vulnerability of industrial systems that include the information technology (IT) and operational technology (OT) to reduce relevant risks. An approach is proposed for verifying the performance level (PL) or the safety integrity level (SIL) of defined safety function, and then to check the level obtained taking into account the security assurance level (SAL) of particular domain, for example, a safety-related control system (SRCS), in which the given safety function is to be implemented. The SAL is determined based on a vector of fundamental requirements (FRs). The method uses defined risk graphs for the individual and/or the societal risk, and relevant risk criteria, for determining the performance level required PLr or the safety integrity level claimed SIL CL, and probabilistic models to verify PL/SIL achievable for the architecture of the SRCS considered.