2022 - Repozytorium publikacji - Politechnika Gdańska

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Comparison of three methods of EPR retrospective dosimetry in watch glass
- Agnieszka Marciniak
- Małgorzata Juniewicz
- Bartłomiej Ciesielski
- Anita Prawdzik-Dampc
- Jakub Karczewski
2022 Pełny tekst Frontiers in Public Health
In this article we present results of our follow-up studies of samples of watch glass obtained and examined within a framework of international intercomparison dosimetry project RENEB ILC 2021. We present three methods of dose reconstruction based on EPR measurements of these samples: calibration method (CM), added dose method (ADM) and added dose&heating method (ADHM). The study showed that the three methods of dose reconstruction gave reliable and similar results in 0.5–6.0Gy dose range, with accuracy better than 10%. The ADHM is the only one applicable in a real scenario, when sample-specific background spectrum is not available; therefore, a positive verification of this method is important for future use of EPR dosimetry in glass in potential radiation accidents
Comparison of thresholding algorithms for automatic overhead line detection procedure
- Paweł Kowalski
- Robert Smyk
2022 Pełny tekst Przegląd Elektrotechniczny
The article presents an overview of the thresholding algorithms. It compares the algorithms proposed by Pun, Kittler, Niblack, Huang, Rosenfeld, Remesh, Lloyd, Riddler, Otsu, Yanni, Kapur and Jawahar. Additionally, it was tested how the tuning of the Pun, Jawahar and Niblack methods affects the thresholding efficiency and proposed a combination of the Pun algorithm with a priori algorithm. All presented algorithms have been implemented and tested for effectiveness in detecting overhead lines.
Compensation of Voltage Drops in Trolleybus Supply System Using Battery-Based Buffer Station
- Mikołaj Bartłomiejczyk
- Leszek Jarzębowicz
- Jiří Kohout
2022 Pełny tekst ENERGIES
This paper analyzes the results of a trial operation of a battery-based buffer station supporting a selected section of trolleybus power supply systems in Pilsen, Czech Republic. The buffer station aims to prevent the catenary from excessive voltage drops in a part of the route that is most remote from the traction substation. Compensation of voltage drops is carried out by continuously measuring the catenary voltage and injecting the current into the catenary if the voltage decreases below a preset value. The effectiveness of such a solution was evaluated by the analysis of numerous experimental recordings, both from the buffer station itself and from trolleybuses in operation. Further on, based on the recordings, a utilized battery capacity was estimated and a control method for decreasing the required capacity was proposed. The optimal capacity analysis, supplemented with an evaluation of required output current rating, was used to define the best storage technology for the considered application.
Composite Materials Based on Silicon Oxycarbide as Anodes for Lithium-Ion Batteries
- Dominik Knozowski
2022 Pełny tekst
In this work, the properties of binary SiOC/graphite and SiOC/tin, as well as ternary SiOC/graphite/tin obtained from various preceramic precursors are described. During the first step, the materials were synthesized using various techniques such as sol-gel and hydrosilylation. To prevent sedimentation and agglomeration of graphite particles during the gelation stage without using surfactants and thickeners, a new gelation technique with utilizing simulations homogenisation and high-power ultrasounds was developed. This method enables a uniform distribution of graphite particles in a polymer blend. In addition, heat generated during this process shortens the gelation time from a few days to a few hours. In the second step, structural and electrochemical characterisation of the obtained materials was conducted. The carbon, ceramic and tin phases were carefully studied in terms of the quantity, structure, morphology, distribution, and in terms of possible reactions that could occur during the synthesis of the materials. In the case of electrochemical measurements, primary focus was on relationships between the content of the additives, the preceramic precursor type, and the resulting microstructure of the composites which influences their final electrochemical properties.
Composition Patterns of Contemporary Polish Residential Building Facades
- Michał Malewczyk
- Antoni Taraszkiewicz
- Piotr Czyż
2022 Nexus Network Journal
This study aims to define the types of composition patterns of contemporary Polish multi-family building facades. The authors define the compositional patterns to determine their frequency. Analyses carried out on the basis of photos and visualizations of 113 examples of architecture from Poland identified groups of common features of facades. Statistical analyses of these features resulted in six types of compositions. Clear differences were noticed in relation to features, such as the repeatability of compositional elements and the method of building a vertical compositional axis. Variations were observed in the frequency and extent of application of specific types of compositions. The results of this study can be a starting point for the development of generative algorithms supporting the process of designing facades. Specifying the types will allow for further exploration of the theme, both in terms of the use of specific compositional measures and in terms of their perception.
Comprehensive analysis of low-temperature methods for reclaiming of ground tire rubber
- Łukasz Zedler
2022 Pełny tekst
Management of waste tires has become an important topic for decades. The lack of an effective method to manage the materials as mentioned above leads to illegal landfills. This problematic waste can be divided into two main categories depending on the physical condition of the waste: (i) partially used tires; (ii) end-of-life tires. While the first group can be reused or retreaded, the second group requires special measures to manage it. At present, the most intensively researched method is the reclaiming of ground tire rubber (GTR). According to literature reports, many approaches have already been made to the subject, among which mechanical, thermal, chemical methods and their combinations have been used. However, the vast majority of these publications do not verify the environmental impact of processing and exploitation of the material. The following dissertation presents an analysis of the available literature on the topic of rubber waste management, as well as my research aimed at (i) developing a GTR processing technology to obtain a product with satisfactory functional properties, (ii) developing a research methodology for GTR-based products considering the gaps in the current state of knowledge, (iii) assessing the environmental impact of GTR processing, and (iv) evaluating the recycling potential of GTR-based products.
Comprehensive Enhancement of Prepolymer-Based Flexible Polyurethane Foams’ Performance by Introduction of Cost-Effective Waste-Based Ground Tire Rubber Particles
- Wiktoria Żukowska
- Paulina Kosmela
- Paweł Wojtasz
- Mariusz Szczepański
- Adam Piasecki
- Roman Barczewski
- Mateusz Barczewski
- Aleksander Hejna
2022 Pełny tekst Materials
Material innovations in polyurethane (PU) foams should ideally combine performance enhancement, environmental impact limitation, and cost reduction. These goals can be achieved by applying recycled or waste-based materials without broader industrial applications, implicating their low price. Herein, from 5 to 20 parts by weight of ground tire rubber (GTR) particles originated from the recycling of postconsumer car tires were incorporated into a flexible foamed PU matrix as a cost-effective waste-based filler. A two-step prepolymer method of foams manufacturing was applied to maximize the potential of applied formulation changes. The impact of the GTR content on the foams’ processing, chemical, and cellular structure, as well as static and dynamic mechanical properties, thermal stability, sound suppression ability, and thermal insulation performance, was investigated. The introduction of GTR caused a beneficial reduction in the average cell diameter, from 263.1 µm to 144.8–188.5 µm, implicating a 1.0–4.3% decrease in the thermal conductivity coefficient. Moreover, due to the excellent mechanical performance of the car tires—the primary application of GTR—the tensile performance of the foams was enhanced despite the disruption of the cellular structure resulting from the competitiveness between the hydroxyl groups of the applied polyols and on the surface of the GTR particles. The tensile strength and elongation at break were increased by 10 and 8% for 20 parts by weight GTR addition. Generally, the presented work indicates that GTR can be efficiently applied as a filler for flexible PU foams, which could simultaneously enhance their performance, reduce costs, and limit environmental impacts due to the application of waste-based material.
Comprehensive evaluation of the carbon footprint components of wastewater treatment plants located in the Baltic Sea region
- Mojtaba Maktabifard
- Alexis Awaitey
- Elina Merta
- Henri Haimi
- Ewa Zaborowska
- Anna Mikola
- Jacek Mąkinia
2022 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
Finland and Poland share similar environmental interests with regard to their wastewater effluents eventually being discharged to the Baltic Sea. However, differences in the influent wastewater characteristics, treatment processes, operational conditions, and carbon intensities of energy mixes in both countries make these two countries interesting for carbon footprint (CF) comparison. This study aimed at proposing a functional unit (FU) which enables a comprehensive comparison of wastewater treatment plants (WWTPs) in terms of their CF. Direct emissions had the highest contribution (70%) to the total CF. Energy consumption dominated the total indirect emissions in both countries by over 30%. Polish WWTPs benefitted more from energy self-sufficiency than Finnish plants as a result of higher electricity emission factors in Poland. The main difference between indirect emissions of both countries were attributed to higher chemical consumption of the Finnish WWTPs. Total pollution equivalent removed (TPErem) FU proposed enabled a better comparison of WWTPs located in different countries in terms of their total CF. High correlations of TPErem with other FUs were found since TPErem could balance out the differences in the removal efficiencies of various pollutants. Offsetting CF was found a proper strategy for the studied WWTPs to move towards low-carbon operation. The studied WWTPs could reduce their CF from up to 27% by different practices, such as selling biofuel, electricity and fertilizers. These findings are applicable widely since the selected WWTPs represent the typical treatment solutions in Poland, Finland and in the Baltic Sea region.
Comprehensive Investigation of Stoichiometry–Structure–Performance Relationships in Flexible Polyurethane Foams
- Adam Olszewski
- Paulina Kosmela
- Adam Piasecki
- Wiktoria Żukowska
- Mariusz Szczepański
- Paweł Wojtasz
- Mateusz Barczewski
- Roman Barczewski
- Aleksander Hejna
2022 Pełny tekst Polymers
Polyurethane (PU) foams are versatile materials with a broad application range. Their performance is driven by the stoichiometry of polymerization reaction, which has been investigated in several works. However, the analysis was often limited only to selected properties and compared samples differing in apparent density, significantly influencing their performance. In the bigger picture, there is still a lack of comprehensive studies dealing with the stoichiometry impact on PU foams’ performance. Herein, flexible PU foams with a similar apparent density but differing in the isocyanate index (IIso) (from 0.80 to 1.20) were prepared. The stoichiometry–structure–performance relationships were investigated considering cellular and chemical structure, as well as the static and dynamic mechanical properties, thermal stability, thermal insulation, and acoustic performance. For IIso of 1.00, the biggest cell diameters of 274 µm were noted, which was 21–25% higher compared to 0.80 and 1.20 values. Increasing IIso reduced open cell content from 83.1 to 22.4%, which, combined with stiffening of structure (rise of modulus from 63 to 2787 kPa) resulting from crosslinking, limited the sound suppression ability around five times. On the other hand, it significantly strengthened the material, increasing tensile and compressive strength 4 and 13 times, respectively. Changes in the foams’ performance were also induced by the glass transition temperature shift from 6.1 to 31.7 ◦C, resulting from a greater extent of urethane groups’ generation and additional isocyanate reactions. Generally, the presented work provides important insights into preparing flexible PU foams and could be very useful for the future development of these materials.
Compressible gas density measurement by means of Fourier analysis of interferograms
- Janusz Telega
- Ryszard Szwaba
- Małgorzata Śmiałek-Telega
2022 Pełny tekst MEASUREMENT
This paper describes a method for nonintrusive compressible gas density measurement by means of automated analysis of interferograms using FFT (Fast Fourier Transform), and its implementation using DFT (Discrete Fourier Transform), that does make this measurement technique a fairly valuable and accessible experimental method. The presented approach makes it possible to use the finite fringe setting of the interferometer, thus reducing adjustment time. In the process of analysis, the errors originating from the imperfections of optical elements are reduced, and a digital image of a virtual infinite setting of the instrument is generated. As described here, the method is extremely beneficial, but not limited to, flows with shock wave – boundary layer interactions. A result of density measured for a flow with shock wave is presented.
Computationally Efficient Surrogate-Assisted Design of Pyramidal-Shaped 3D Reflectarray Antennas
- Peyman Mahouti
- Mehmet Belen
- Nurullah Calik
- Sławomir Kozieł
2022 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
Reflectarrays (RAs) have been attracting considerable interest in the recent years due to their appealing features, in particular, a possibility of realizing pencil-beam radiation patterns, as in the phased arrays, but without the necessity of incorporating the feeding networks. These characteristics make them attractive solutions, among others, for satellite communications or mobile radar antennas. Notwithstanding, available microstrip implementations are inherently narrow-band, and heavily affected by conductor and surface wave losses. RAs based on grounded dielectric layers offer improved performance and flexibility in terms of shaping the phase reflection response. In either case, a large number of variables (induced by the need for independent adjustment of individual unit cell geometries), and the necessity of handling several requirements, make the design process of reflectarrays a challenging endeavor. In particular, RA optimization is extremely expensive when conducted at the level of EM simulation models, otherwise necessary to ensure reliability. A practical solution is surrogate-assisted design with the metamodels constructed for the RA unit elements. Unfortunately, conventional modeling methods require large numbers of training data samples to render accurate surrogates, which turns detrimental to the optimization process efficiency. This work proposes an alternative approach with the unit element representations constructed using deep learning with automated adjustment of the model architecture. As a result, design-ready surrogates can be constructed using only a few hundred samples, and the total RA optimization cost is reduced to only a handful of equivalent EM analyses of the entire array. Our approach is validated using an RA incorporating 3D pyramidal-shaped elements and favorably compared to benchmark techniques. Experimental verification of the obtained design is discussed as well.
Computer Aided Telediagnostics System for Stoma Patients
- Rafal Zawislak
- Mariusz Szwoch
- Grzegorz Granosik
- Anna Miarka
- Joanna Mik-Wojtczak
- Michal Mik
2022
Stoma surgery may concern patients with colorectal cancer and inflammatory bowel disease. More than half of patients diagnosed with colon cancer present at an advanced stage, and palliative treatment may involve stoma formation. This type of surgery may change the patient’s life strongly, therefore they should receive special medical care. The paper presents the assumptions, concept, and architecture of the Stoma-Alert diagnosis support system, including the assessment of stoma complications and issuing recommendations for treatment and care. In particular, the telediagnosis subsystem, which is essential in the pandemic era, supports the assessment of stoma status on the basis of photos and symptoms provided remotely by the patient. The first experiences in the development of the system and interaction with it, both on the part of doctors and medical personnel, as well as the patients themselves, are also presented.
Computer-Aided Automated Greenery Design—Towards a Green BIM
- Dominik Sędzicki
- Jan Cudzik
- Lucyna Nyka
- Wojciech Bonenberg
2022 Pełny tekst Sustainability
Contemporary climate challenges are changing the architect’s awareness, which results in a broader spectrum of interest. The available software enables the design of vegetation, but it is often very limited and requires specialist knowledge. The available software allows the creation of individual solutions based on visual algorithms or writing scripts; however, they are still not common methods used in architecture and urban planning. The study proposes a new complex digital method of selection and design of greenery based on a new parameter spreadsheet. The proposition is supported by the review and investigation of the software used by designers identifying a range of tools for the design of greenery. The study proposes a theoretical model for automated plant selection and variations of possible greenery scenarios that could be integrated into the design process at the early stages of concept development.
Computer-Aided Detection of Hypertensive Retinopathy Using Depth-Wise Separable CNN
- Imran Qureshi
- Qaisar Abbas
- Junhua Yan
- Ayyaz Hussain
- Kashif Shaheed
- Abdul Rauf Baig
2022 Pełny tekst Applied Sciences-Basel
Hypertensive retinopathy (HR) is a retinal disorder, linked to high blood pressure. The incidence of HR-eye illness is directly related to the severity and duration of hypertension. It is critical to identify and analyze HR at an early stage to avoid blindness. There are presently only a few computer-aided systems (CADx) designed to recognize HR. Instead, those systems concentrated on collecting features from many retinopathy-related HR lesions and then classifying them using traditional machine learning algorithms. Consequently, those CADx systems required complicated image processing methods and domain-expert knowledge. To address these issues, a new CAD-HR system is proposed to advance depth-wise separable CNN (DSC) with residual connection and a linear support vector machine (LSVM). Initially, the data augmentation approach is used on retina graphics to enhance the size of the datasets. Afterward, this DSC approach is applied to retinal images to extract robust features. The retinal samples are then classified as either HR or non-HR using an LSVM classifier as the final step. The statistical investigation of 9500 retinograph images from two publicly available and one private source is undertaken to assess the accuracy. Several experimental results demonstrate that the CAD-HR model requires less computational time and fewer parameters to categorize HR. On average, the CAD-HR achieved a sensitivity (SE) of 94%, specificity (SP) of 96%, accuracy (ACC) of 95% and area under the receiver operating curve (AUC) of 0.96. This confirms that the CAD-HR system can be used to correctly diagnose HR.
Computer-assisted pronunciation training—Speech synthesis is almost all you need
- Daniel Korzekwa
- Jaime Lorenzo-trueba
- Thomas Drugman
- Bożena Kostek
2022 Pełny tekst SPEECH COMMUNICATION
The research community has long studied computer-assisted pronunciation training (CAPT) methods in non-native speech. Researchers focused on studying various model architectures, such as Bayesian networks and deep learning methods, as well as on the analysis of different representations of the speech signal. Despite significant progress in recent years, existing CAPT methods are not able to detect pronunciation errors with high accuracy (only 60% precision at 40%–80% recall). One of the key problems is the low availability of mispronounced speech that is needed for the reliable training of pronunciation error detection models. If we had a generative model that could mimic non-native speech and produce any amount of training data, then the task of detecting pronunciation errors would be much easier. We present three innovative techniques based on phoneme-to-phoneme (P2P), text-to-speech (T2S) and speech-to-speech (S2S) conversion to generate correctly pronounced and mispronounced synthetic speech. We show that these techniques not only improve the accuracy of three machine learning models for detecting pronunciation errors, but also help establish a new state-of-the-art in the field. Earlier studies have used simple speech generation techniques such as P2P conversion, but only as an additional mechanism to improve the accuracy of pronunciation error detection. We, on the other hand, consider speech generation to be the first-class method of detecting pronunciation errors. The effectiveness of these techniques is assessed in the tasks of detecting pronunciation and lexical stress errors. Non-native English speech corpora of German, Italian, and Polish speakers are used in the evaluations. The best proposed S2S technique improves the accuracy of detecting pronunciation errors in AUC metric by 41% from 0.528 to 0.749 compared to the state-of-the-art approach.
Con l’introduzione
- Luciano Segreto
2022
Nata nel 1953 con l’obiettivo di portare l’Italia tra le nazioni avanzate anche in campo energetico, Eni rappresenta una delle principali imprese ad aver influenzato l’innovazione economica del Paese. La sua storia, legata a doppio filo alla figura di Enrico Mattei, consente di seguirne le traiettorie di sviluppo e le strategie di internazionalizzazione, nel quadro di un contesto in continua evoluzione. Questo volume ripercorre quasi cento anni di documenti: i saggi che lo compongono – frutto di ricerche originali, condotte in molti archivi, prima di tutto in quello di Eni – consentono di seguire da vicino il lungo percorso della storia energetica italiana.
CONCRETE MIX DESIGN USING ABRAMS AND BOLOMEY METHODS
- Salem Abdelgader
- Marzena Kurpińska
- Jamal Khatib
- Hakim S. Abdelgader
2022 Pełny tekst BAU Journal - Science and Technology
One way to reduce the consumption of cement is to optimize its use. Many known methods of concrete design, based on the Abrams law and the Bolomey method. Therefore, the authors chose those methods for analysis. The concrete composition with the assumed strength class, calculated by any method differs significantly. This applies especially to the cement content, as its content in the composition of concrete varies from 20 to 50%. The authors presented the computational analysis and the results of laboratory tests of concrete samples with the assumed compressive strengths of 25, 30, 35, 40 and 45 MPa and for two consistency classes plastic and liquid. Moreover, the tensile strength tests results of the samples due to splitting presented. The authors defined the scope of application of the calculation methods according to the Abrams and Bolomey methods.
Condition-Based Monitoring of DC Motors Performed with Autoencoders
- Krzysztof Włódarczak
- Łukasz Grzymkowski
- Tomasz Stefański
2022
This paper describes a condition-based monitoring system estimating DC motor degradation with the use of an autoencoder. Two methods of training the autoencoder are evaluated, namely backpropagation and extreme learning machines. The root mean square (RMS) error in the reconstruction of successive fragments of the measured DC motor angular-frequency signal, which is fed to the input of autoencoder, is used to determine the health indicator (HI). A complete test bench is built using a Raspberry Pi system (i.e., motor driver controlling angular frequency) and Jetson Nano (i.e., embedded compute node to estimate motor degradation) to perform exploratory analysis of autoencoders for condition-based monitoring and comparison of several classical artificial intelligence algorithms. The experiments include detection of degradation of DC motor working in both constant and variable work points. Results indicate that the HI obtained with the autoencoders trained with the use of either training method is suitable for both work points. Next, an experiment with multiple autoencoders trained on each specific work point and running in parallel is reviewed. It is shown that, in this case, the minimum value of RMS error among all autoencoders should be taken as HI. Furthermore, it has been shown that there is a nearlinear relationship between HI and the difference between measured and reconstructed angular-frequency waveforms.
CONDITIONING FACTORS OF INDUSTRY-UNIVERSITY COOPERATION FROM THE PERSPECTIVE OF ENTERPRISES
- Sylwia Sieracka
- Marek Wirkus
2022 Pełny tekst Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska
The cooperation between enterprises and universities varies in terms of character and intensity. Bearing in mind the potential represented by both parties, its low intensity is still noticed, and consequently, the lack or incomplete use of opportunities resulting from this cooperation. Current factors of industry-university cooperation were identified from the perspective of companies from biotechnology and pharmaceutical industries, as well as the conditions shaping these factors. The so-called 'overfactors' of cooperation with the university were distinguished, which should be particularly emphasized in order to intensify the cooperation. The dependence and change of factors on the stage of cooperation and industry were found, which may have an impact on the type of factors determining cooperation with universities. Współpraca przedsiębiorstw z uczelniami ma różny charakter i intensywność. Biorąc pod uwagę potencjał reprezentowany przez obie strony, wciąż zauważalny jest niski poziom jej intensywności, a co za tym idzie brak lub niepełne wykorzystanie szans wynikających z kooperacji obu podmiotów. W pracy przedstawiono aktualne czynniki współpracy przemysł-uczelnia z perspektywy przedsiębiorstw branży biotechnologicznej i farmaceutycznej oraz uwarunkowania kształtujące te czynniki. Wyróżniono tzw. „nadczynniki”, któremu należy poświęcić szczególną uwagę w celu zintensyfikowania współpracy przemysł-uczelnia. Ponadto stwierdzono zależność i zmianę czynników na poszczególnych etapach kooperacji oraz branży, co może mieć wpływ na rodzaj czynników determinujących tę współpracę.
Conditions for Multiple Acquisition of Echoes from Stationary Targets in Successive Transmissions of Active Sonars
- Lech Kilian
- Aleksander Schmidt
- Mariusz Rudnicki
2022 Pełny tekst Vibrations in Physical Systems
In echolocation, the highest possible number of contacts with a detected target is clearly decisive on the possibilities of echo processing to optimise the estimation of distinctive characteristics of the observed target. In hydrolocation, the slow propagation of acoustic waves in water reduces the number of contacts of echosounders and sonars with detected targets. The article considers model conditions for acquiring multiple contacts with stationary targets detected by various sounding methods - with echosounders, classic active sonars and side looking sonars. Appropriate formulas explicitly linking the possible number of echo signals from the target in a specific geometry of the survey performed at the assumed speed are presented. These formulas are intuitively clear and not very complicated, but their value lies in the ability to instantly combine the vessel speed with the sounding effects, and may be a clear argument for imposing a low sounding speed, which make it difficult to steer the vessel.