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Gdańsk University of Technology

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  • Application of discrete wavelet transform in seismic nonlinear analysis of soil–structure interaction problems
    • Reza Kamgar
    • Reihaneh Tavakoli
    • Peyman Rahgozar
    • Robert Jankowski
    2021 EARTHQUAKE SPECTRA

    Simulation of soil-structure interaction (SSI) effects is a time-consuming and costly process. However, ignoring the influence of SSI on structural response may lead to inaccurate results, especially in the case of seismic nonlinear analysis. In this paper, wavelet transform methodology has been utilized for investigation of the seismic response of soil-structure systems. For this purpose, different storey outrigger braced buildings resting on two different types of soil have been considered for SSI analysis. For each SSI system, several seismic records, with different values of peak ground acceleration (PGA) and peak ground velocity (PGV), have been firstly decomposed into approximate and detailed signals using a discrete wavelet transform. Then, seismic responses of the SSI systems subjected to the approximate signal have been evaluated. The results of the study show that, for earthquakes with low PGA/PGV ratio, the error percentage of all the parameters is smaller than 5% for the first level, and the error-index is below 10% for the third level. As the PGA/PGV ratio of an earthquake increases, the concordance of approximate results with the main results decreases. However, even for the earthquakes with the PGA/PGV ratio higher than 1.2 g·sec/m, the first-level approximation can be used to predict seismic responses with at least 90% accuracy while significantly reducing the computational time.

  • APPLICATION OF ENTROPY-BASED METHODS TO DISTINGUISH HEALTHY INDIVIDUALS WITH NORMAL SINUS RHYTHM FROM PATIENTS WITH CONGESTIVE HEART FAILURE
    • Katarzyna Tessmer
    2021

    In this paper, we examined whether entropy-based methods are able to differentiate healthy individuals from patients with congestive heart failure. To this aim, we applied two methods: Permutation Entropy and Block Entropy. Long-term ECG recordings (75 000 RR intervals) were analyzed. The results proved that both methods can distinguish those groups on condition that the parameters are appropriately chosen.

  • Application of Open-Hardware-Based Solutions for Rapid Transition From Stationary to the Remote Teaching Model During Pandemic
    • Adrian Bekasiewicz
    • Bogdan Pankiewicz
    • Marek Wójcikowski
    • Miron Kłosowski
    • Sławomir Kozieł
    2021 IEEE Transactions on Education

    While research indicates usefulness of remote laboratories in teaching of digital hardware systems, their main application is to complement stationary classes. This work presents a low-cost, scalable architecture that supports rapid transformation of teaching to a model based solely on remote access mechanisms. Background: Adaptation of online laboratory solutions from the literature to en-masse teaching of digital circuits is timeconsuming and expensive. Solutions that permit cheap and rapid conversion of courses to remote environments seem to be of high value, especially when social distancing renders direct teaching impossible. Intended Outcomes: Demonstration of a flexible and cheap architecture that permits rapid transformation of digital circuits laboratories to the remote environment. Validation of system’s performance and usefulness on a large group of students. Application Design: Remote digital circuits laboratories from the literature are designed to complement stationary classes. For successful teaching during pandemic, a low-cost, flexible, and efficient solution to online laboratory based on commonly available technologies is required. Findings: The proposed remote laboratory architecture enables rapid conversion of on-site teaching to online model, while supporting in-situ upgrades and functionality enhancements. The presented solution proved to be a convenient substitute for conventional laboratories during pandemic.

  • Application of regularized Savitzky–Golay filters to identification of time-varying systems
    • Maciej Niedźwiecki
    • Marcin Ciołek
    • Artur Gańcza
    • Piotr Kaczmarek
    2021 Full text AUTOMATICA

    Savitzky–Golay (SG) filtering is a classical signal smoothing technique based on the local least squares approximation of the analyzed signal by a linear combination of known functions of time (originally — powers of time, which corresponds to polynomial approximation). It is shown that the regularized version of the SG algorithm can be successfully applied to identification of time-varying finite impulse response (FIR) systems. Such a solution is possible owing to the recently proposed preestimation technique, which converts the problem of identification of a time-varying FIR system into the problem of smoothing of the appropriately generated preestimates of system parameters. The resulting fast regularized local basis function estimators, optimized using the empirical Bayes approach, have very good parameter tracking capabilities, favorably comparing with the state-of-the-art in terms of accuracy, computational complexity and numerical robustness.

  • Application of shifted Chebyshev polynomial-based Rayleigh–Ritz method and Navier’s technique for vibration analysis of a functionally graded porous beam embedded in Kerr foundation
    • Subrat Kumar Jena
    • S. Chakraverty
    • Mohammad Malikan
    2021 Full text ENGINEERING WITH COMPUTERS

    Present study is dealt with the applicability of shifted Chebyshev polynomial based Rayleigh-Ritz method and Navier’s technique on free vibration of Functionally Graded (FG) beam with uniformly distributed porosity along the thickness of the beam. The material properties such as Young’s modulus, mass density, and Poisson’s ratio are also considered to vary along the thickness of the FG beam as per the power-law exponent model. The porous FG beam is embedded in an elastic substrate; namely, the Kerr elastic foundation and the displacement field of the beam is governed by a Refined Higher Order Shear Deformation Theory (RHSDT). The effectiveness of the Rayleigh-Ritz method is due to the use of the shifted Chebyshev polynomials as a shape function. The orthogonality of shifted Chebyshev polynomial makes the technique more computationally efficient and avoid ill-conditioning for the higher number of terms of the polynomial. Hinged-Hinged (HH), Clamped-Hinged (CH), Clamped-Clamped (CC), and Clamped-Free (CF) boundary conditions have been taken into account for the parametric study. Validation of the present model is examined by comparing it with existing literature in special cases showing remarkable agreement. A pointwise convergence study is also carried out for shifted Chebyshev polynomial based Rayleigh-Ritz method and the effect of power-law exponent, porosity volume fraction index, and elastic foundation on natural frequencies are studied comprehensively.

  • Application of Spinel and Hexagonal Ferrites in Heterogeneous Photocatalysis
    • Zuzanna Bielan
    • Szymon Dudziak
    • Adam Kubiak
    • Ewa Kowalska
    2021 Full text Applied Sciences-Basel

    Semiconducting materials display unique features that enable their use in a variety of applications, including self-cleaning surfaces, water purification systems, hydrogen generation, solar energy conversion, etc. However, one of the major issues is separation of the used materials from the process suspension. Therefore, chemical compounds with magnetic properties have been proposed as crucial components of photocatalytic composites, facilitating separation and recovery of photocatalysts under magnetic field conditions. This review paper presents the current state of knowledge on the application of spinel and hexagonal ferrites in heterogeneous photocatalysis. The first part focuses on the characterization of magnetic (nano)particles. The next section presents the literature findings on the single-phase magnetic photocatalyst. Finally, the current state of scientific knowledge on the wide variety of magnetic-photocatalytic composites is presented. A key aim of this review is to indicate that spinel and hexagonal ferrites are considered as an important element of heterogeneous photocatalytic systems and are responsible for the effective recycling of the photocatalytic materials.

  • Application of the F-statistic of the Fisher-Snedecor distribution to analyze the significance of the effect of changes in the compression ratio of a diesel engine on the value of the specific enthalpy of the exhaust gas flow
    • Patrycja Puzdrowska
    2021 Full text Combustion Engines

    The paper discusses the impact of changes in the compression ratio on the operating parameters of a diesel engine, e.g. on the temperature of exhaust gases. It presents the construction of the laboratory test stand, on which experimental measurements were realized. It is characterized how the actual changes of the compression ratio were introduced to the existing engine. The program of experimental investigations taking into account the available test stand and measurement possibilities was described. A statistical and qualitative analysis of the obtained measurement results was made. The use of F statistics of the Fisher-Snedecor distribution was proposed to assess the significance of the effect of compression ratio changes on the specific enthalpy of the exhaust gas stream. The specific enthalpy of exhaust gases was analysed for one cycle of diesel engine work, determined on the basis of the course of quickly varying temperature of exhaust gases. The results of these analyses are discussed and the utilitarian purpose of this type of evaluation in parametric diagnostics of piston engines is presented.

  • Application of ultrasound-assisted solvent extraction of porous membrane packed liquid samples for polyphenols determination in wine samples
    • Magdalena Fabjanowicz
    • Alicia Robles
    • Justyna Płotka-Wasylka
    2021 Full text

    Polyphenols play a crucial role in a proper human health maintenance as well as their presence very often correspond to the quality assessment of producs like wine. Thus, their monitoring is of high interest. However, as they occur in a complex matrices their extraction is very often necessary prior the analysis. Herein, a new ultrasound-assisted solvent extraction of porous membrane packed liquid sample technique has been optimized for the determination of polyphenols in wine samples as an alternative for existing methods used prior gas chromatography – mass spectrometry analysis. Achieved accuracy is in the range of 100.7 – 108.3 while recovery between 97 – 110% from spiked samples at 5 to 10 ppm concentration range. LOD ranges between 0.174-1.99 µg/mL while LOQ 0.522-5.97 µg/mL.

  • Applications of Additively Manufactured Tools in Abrasive Machining—A Literature Review
    • Mariusz Deja
    • Dawid Zieliński
    • Aini Zuhra Abdul Kadir
    • Siti Nur Humaira
    2021 Full text Materials

    High requirements imposed by the competitive industrial environment determine the development directions of applied manufacturing methods. 3D printing technology, also known as additive manufacturing (AM), currently being one of the most dynamically developing production methods, is increasingly used in many different areas of industry. Nowadays, apart from the possibility of making prototypes of future products, AM is also used to produce fully functional machine parts, which is known as Rapid Manufacturing and also Rapid Tooling. Rapid Manufacturing refers to the ability of the software automation to rapidly accelerate the manufacturing process, while Rapid Tooling means that a tool is involved in order to accelerate the process. Abrasive processes are widely used in many industries, especially for machining hard and brittle materials such as advanced ceramics. This paper presents a review on advances and trends in contemporary abrasive machining related to the application of innovative 3D printed abrasive tools. Examples of abrasive tools made with the use of currently leading AM methods and their impact on the obtained machining results were indicated. The analyzed research works indicate the great potential and usefulness of the new constructions of the abrasive tools made by incremental technologies. Furthermore, the potential and limitations of currently used 3D printed abrasive tools, as well as the directions of their further development are indicated.

  • Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
    • Fatemeh Molaei
    • Maryam Zarghami Dehaghani
    • Azam Salmankhani
    • Sasan Fooladpanjeh
    • S. Mohammad Sajadi
    • Mohammad Esmaeili Safa
    • Otman Abida
    • Sajjad Habibzadeh
    • Amin Hamed Mashhadzadeh
    • Mohammad Saeb
    2021 COMPUTATIONAL MATERIALS SCIENCE

    Graphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet. The mechanical responses of defect-free and defective MSiCNS and PSiCNS having regular cracks and circular-shaped notches were captured as a function of temperature (100–1200 K), such that elevated temperatures were unconditionally deteriorative to the properties. Moreover, larger cracks and notches more severely decreased the strength of PSiCNS, e.g. Young’s modulus dropped to ca. 41% by the crack enlargement. The temperature rise similarly deteriorated the failure stress and Young's modulus of PSiCNS. However, the stress intensity factor increased by the enlargement of the crack length but decreased against temperature. We believe that the findings of the present study can shed some light on designing mechanically stable nanostructures for on-demand working conditions.

  • Applying response surface method to optimize the performance of a divergent-chimney solar power plant
    • Behrouz Adibimanesh
    • Mohammad Bagher Ayani
    • Hojjat Khozeymeh-Nezhad
    • Sylwia Polesek-Karczewska
    2021 Full text Sustainable Energy Technologies and Assessments

    One of the effective tools to generate electricity from solar energy is Divergent-chimney solar power plant (DSPP). Divergent and cylindrical chimneys of solar power plants have different performances considering turbine pressure drop ratio (ft). For the first time, the divergent angle (DA) and solar radiation (SR) interaction effects on 〖ft〗_opt are discussed through applying the Computational Fluid Dynamics (CFD) and Response Surface Method (RSM). FLUENT software is employed to perform 2D axisymmetric numerical stimulation for the Manzanares prototype. The DA, SR, and ft with ranges of 0°-3°, 200-800 W/m2, and 0.2-0.9 are considered, respectively, in the RSM optimization. The outcomes denote that the amount of 〖ft〗_optvaries from 0.71 to 0.89 continuously, and it is related inversely to the DA and directly to the SR. The maximum efficiency 〖(η〗_max) is obtained at 〖ft〗_opt, for different SRs and DAs. It is concluded that the η_max is enhanced from 0.42% to 0.50%, achieved by increasing the DA and SR values. Furthermore, the quadratic correlation of the 〖ft〗_opt and η_max in terms of DA and SR parameters are provided. Therefore, the consequences of this research would be a suitable resource for designing optimum turbines for the DSPPs.

  • Approval of an Arrangement in the Restructuring Proceedings and the Financial Condition of Companies Listed on the Stock Exchanges in Warsaw. Is There Any Relationship?
    • Błażej Prusak
    • Paweł Galiński
    2021 Full text Journal of Risk and Financial Management

    This paper attempts to identify the financial indicators differentiating companies that are insolvent or at risk of insolvency and have successfully entered into an arrangement with their creditors from those that have not. In addition, a two-factor model for predicting the odds of an arrangement has been proposed. The research was conducted using a population of companies listed on stock exchanges in Warsaw that initiated restructuring proceedings between October 2004 and 31 December 2020. Binary logistic regression was used as the research method. The research shows that the financial health of public companies in Poland, as measured by various financial indicators, has little impact on the effectiveness of a debtor–creditor arrangement. The main measure showing discriminatory features between groups of successful and unsuccessful entities is the share of shortterm liabilities in total liabilities. A statistically significant influence was also recorded for the indicator showing the share of short-term receivables in the total assets. Furthermore, a statistically significant discriminatory power for both groups was recorded for the indicator showing the ratio of inventories to sales revenue. However, in this situation the selection of this measure was due to the industry diversity of the research population. The identification of these determinants and the proposed model may help courts and supervisors to divide insolvent companies into those that should be subject to liquidation or restructuring procedures at an early stage of the proceedings. Consequently, this can significantly reduce the direct and indirect costs of implementing bankruptcy proceedings.

  • Appunti di corporate governance
    • Alessandro Minichilli
    • Fabio Quarato
    • Luciano Segreto
    2021

    Il libro pone la proprietà al centro di tutte le scelte rilevanti che l’impresa compie: in particolare affronta il «problema» del governo il tema della corporate governance dalla prospettiva della proprietà e in un’accezione più ampia e articolata rispetto agli studi di matrice anglosassone. In questo contesto, si analizza il tema delle relazioni tra proprietà, governo corporate governance e strategia corporate delle imprese, con un duplice obiettivo. Da una parte, si tratta di individuare le relazioni di coerenza tra l’assetto di governance dell’impresa e i suoi risultati, in ragione della centralità che questa assume rispetto a molte delle scelte strategiche che le imprese compiono. Dall’altra, l’obiettivo è quello di considerare le possibili varianti allo “schema base”, andando a investigare il ruolo di proprietà, governo e direzione in ottica contingency, ossia nei diversi tipi di impresa. Nello specifico, vengono analizzate le imprese le public companies, le imprese multinazionali (multi-national enterprises), quelle a controllo statale (state-owned enterprises), e soprattutto le imprese a controllo familiare. La seconda parte del lavoro analizza, in una serie di paesi i sistemi economici, i modelli di capitalismo, le diverse culture economiche, i condizionamenti storici, giuridici e istituzionali e il loro ruolo nel definire il tipo di corporate governance che si è affermato

  • Aqueous Molybdate Provides Effective Corrosion Inhibition of WE43 Magnesium Alloy in Sodium Chloride Solutions
    • Dmitry Kharitonov
    • Małgorzata Zimowska
    • Jacek Ryl
    • Artur Zieliński
    • Maria Osipenko
    • Janusz Adamiec
    • Angelika Wrzesińska
    • Per Claesson
    • Irina Kurilo
    2021 Full text CORROSION SCIENCE

    Corrosion and corrosion inhibition of WE43 magnesium alloy were investigated in NaCl solutions containing different amounts of sodium molybdate. Electrochemical, microscopic, and spectroscopic experiments were utilized to examine the mechanism of corrosion inhibition by molybdates. Electrochemical data showed that Na2MoO4 inhibitor provides reliable inhibition at concentrations at and above 100 mM. Raman and XPS spectroscopy demonstrated that the formed surface layer consists of mixed Mo(V, IV) species. This layer provided inhibition with an efficiency of 91–99% after 24 h of exposure. A two-step oxidation-reduction mechanism of corrosion inhibition of the WE43 alloy by aqueous molybdates was proposed

  • Architecture in the field of art on the example of author’s realizations
    • Agnieszka Kurkowska
    2021 Full text Architectus

    The aim of the article was to show the place of architecture in the space of art on the example of original projects. In the author's opinion, architecture, using an artistic object as a means of expression, influences the process of living by showing the recipient, who is an inhabitant, important values from the point of view of creating a house that ensures a good quality of life and strengthening the understanding of both various aspects of living and elements of the house structure. The text presents original intentional projects, in a way the results of research work, and presents the manner and scope of their impact on the living process. The subject of the three described projects were spatial installations using, in two cases, ideological architectural sculptures as an artistic medium. All the projects had home and habitation as their leading themes. Their task was to recall memories, strengthen the sense of identification, or recall the values supporting the said dwelling. During the research, ideological architectural sculptures were placed in the natural landscape of Kashubia and in a block of flats. Appropriate photographic and descriptive documentation was made, constituting the basis for work according to the analytical and comparative method. An attempt was also made to conduct a survey of project participants and recipients. The article not only presents original attempts, the considerations contained in it may also inspire non-obvious activities, combining science and art, indicating the applicative nature of the first and the essence of the second.

  • Architecture of ecumenical spaces in public buildings in the 21st century: Links among the architecture of multi-faith spaces, their names, and the functions they serve in Polish airports
    • Agnieszka Szuta
    2021 Full text Frontiers of Architectural Research

    This study explores the architecture and arrangement of prayer spaces in public buildings. It examines whether Polish airports have prayers spaces and whether a correlation exists between the name (e.g., “multi-faith space,” “place of prayer,” and “place of focus”) and design. The study is supported by analyses of ecumenical spaces, which have recently been brought into service andwhere a visible symbiosis exists between their names and functions. This study includes in situ investigations and is conducted based on awide range of literature, statistical data, comparativemethods, and logical reasoning. This study may provide an important indication for countries that are only beginning to face a design problem concerning architecture of multi-faith spaces.

  • Architektura zintegrowana z zielenią. Szpalery drzew liściastych jako ochrona przeciwsłoneczna budynków
    • Justyna Janiak
    2021 Full text

    Praca dotyczy integracji drzew i architektury jako formy ochrony przeciwsłonecznej budynku w zabudowie miejskiej. Wykorzystanie zieleni wysokiej jako elementu zacieniającego zabudowę zbadano na przykładzie wybranego układu, tj. ulicy wraz ze szpalerem drzew liściastych wzdłuż każdej z pierzei przy uwarunkowaniach wilgotnego klimatu kontynentalnego. W analizie nasłonecznienia elewacji osłoniętej przez roślinne elementy zacieniające uwzględniono różne warianty odległości zadrzewień od ścian w modelach ulicy o orientacji wschód-zachód i północ-południe oraz o parametrach proporcji H/W równych: 0,2; 0,4; 0,6; 1 i 2. Badania układu wykonano w oparciu o numeryczne metody symulacyjne z wykorzystaniem komponentu godzin nasłonecznienia, który jest dostępny w nakładce Ladybug Tools programu Rhinoceros® 6. Na podstawie otrzymanych wyników stwierdzono, że szpalery drzew liściastych (o badanych parametrach) mogą pełnić rolę rozwiązania alternatywnego bądź uzupełniającego do systemów zacieniających zintegrowanych z budynkami. Skuteczność zieleni w tym zakresie zależy od relacji geometrycznych między zabudową a drzewami oraz od geometrii i orientacji tego modelu względem świata. W pracy przedstawiono również metodę modelowania oraz oceny układów roślinno-architektonicznych z drzewami pod kątem ochrony przeciwsłonecznej zabudowy, którą można wykorzystać jako narzędzie wspomagające projektowanie.

  • Arctic Freshwater Environment Altered by the Accumulation of Commonly Determined and Potentially New POPs
    • Klaudia Kosek
    • Marek Ruman
    2021 Full text Water

    Chemical composition of Arctic freshwater ecosystems depends on several factors. They include characteristics of the surrounding landscape, its lithology, geomorphology, vegetation, and hydrological features, as well as accumulation of anthropogenic pollution. In the Arctic, the problem of environmental contamination is widespread. That is why research on lakes and river catch-ments in terms of their chemical composition has enjoyed increasing interest among scientists worldwide. The freshwater reservoirs of the Arctic are fragile and particularly vulnerable to the uptake of pollutants that become trapped in the water and sediments for an extended period. This review summarises selected studies of freshwater bodies in the Arctic to highlight the problem of the accumulation of pollutants in these reservoirs. Moreover, it emphasises the possible negative impact of chemical pollutants on both animal and human health.

  • Are deep eutectic solvents useful in chromatography? A short review
    • Justyna Płotka-Wasylka
    • Małgorzata Rutkowska
    • Miguel de la Guardia
    2021 Full text JOURNAL OF CHROMATOGRAPHY A

    A literature update has been done concerning Deep Eutectic Solvents (DES) use in chromatography applications. The literature survey was based on the period from 2010 till 2020 and manuscripts reported in the data bases Web of Science and Scopus. The use of DES as mobile phase and mobile phase additives, stationary phases and solid phase modifiers and the use of DES as reaction solvents for chromatography use, were evaluated. Emphasis was placed on the differentiation of DES and Ionic Liquids (ILs) and the advanced green characteristics of the new solvents as compared with traditional organic solvents and ILs with a look into the drawbacks and future perspectives in the field of separation methods.

  • Arithmetic Loophole in Bell's Theorem: Overlooked Threat to Entangled-State Quantum Cryptography
    • Marek Czachor
    2021 Full text ACTA PHYSICA POLONICA A

    Bell’s theorem is supposed to exclude all local hidden-variable models of quantum correlations. However,an explicit counterexample shows that a new class of local realistic models, based on generalized arith-metic and calculus, can exactly reconstruct rotationally symmetric quantum probabilities typical oftwo-electron singlet states. Observable probabilities are consistent with the usual arithmetic employedby macroscopic observers but counterfactual aspects of Bell’s theorem are sensitive to the choice ofhidden-variable arithmetic and calculus. The model is classical in the sense of Einstein, Podolsky,Rosen and Bell: elements of reality exist and probabilities are modeled by integrals of hidden-variableprobability densities. Probability densities have a Clauser–Horne product form typical of local realistictheories. However, neither the product nor the integral nor the representation of rotations are the usualones. The integral has all the standard properties but only with respect to the arithmetic that definesthe product. Certain formal transformations of integral expressions found in the usual proofs à la Belldo not work, so standard Bell-type inequalities cannot be proved. The system we deal with is de-terministic, local-realistic, rotationally invariant, observers have free will, detectors are perfect, hencethe system is free of all the canonical loopholes discussed in the literature

  • Artificial Intelligence Technologies in Education: Benefits, Challenges and Strategies of Implementation
    • Mieczysław Owoc
    • Agnieszka Sawicka
    • Paweł Weichbroth
    2021 Full text

    Since the education sector is associated with highly dynamic business environments which are controlled and maintained by information systems, recent technological advancements and the increasing pace of adopting artificial intelligence (AI) technologies constitute a need to identify and analyze the issues regarding their implementation in education sector. However, a study of the contemporary literature reveled that relatively little research has been undertaken in this area. To fill this void, we have identified the benefits and challenges of implementing artificial intelligence in the education sector, preceded by a short discussion on the concepts of AI and its evolution over time. Moreover, we have also reviewed modern AI technologies for learners and educators, currently available on the software market, evaluating their usefulness. Last but not least, we have developed a strategy implementation model, described by a five-stage, generic process, along with the corresponding configuration guide. To verify and validate their design, we separately developed three implementation strategies for three different higher education organizations. We believe that the obtained results will contribute to better understanding the specificities of AI systems, services and tools, and afterwards pave a smooth way in their implementation.

  • Assessing business process complexity based on textual data: Evidence from ITIL IT ticket processing
    • Nina Rizun
    • Aleksandra Revina
    • Vera Maister
    2021 Full text Business Process Management Journal

    Purpose This study aims to draw the attention of business process management (BPM) research and practice to the textual data generated in the processes and the potential of meaningful insights extraction. The authors apply standard natural language processing (NLP) approaches to gain valuable knowledge in the form of business process (BP) complexity concept suggested in the study. It is built on the objective, subjective and meta-knowledge extracted from the BP textual data and encompassing semantics, syntax and stylistics. As a result, the authors aim to create awareness about cognitive, attention and reading efforts forming the textual data-based BP complexity. The concept serves as a basis for the development of various decision-support solutions for BP workers. Design/methodology/approach The starting point is an investigation of the complexity concept in the BPM literature to develop an understanding of the related complexity research and to put the textual data-based BP complexity in its context. Afterward, utilizing the linguistic foundations and the theory of situation awareness (SA), the concept is empirically developed and evaluated in a real-world application case using qualitative interview-based and quantitative data-based methods. Findings In the practical, real-world application, the authors confirmed that BP textual data could be used to predict BP complexity from the semantic, syntactic and stylistic viewpoints. The authors were able to prove the value of this knowledge about the BP complexity formed based on the (1) professional contextual experience of the BP worker enriched by the awareness of cognitive efforts required for BP execution (objective knowledge), (2) business emotions enriched by attention efforts (subjective knowledge) and (3) quality of the text, i.e. professionalism, expertise and stress level of the text author, enriched by reading efforts (meta-knowledge). In particular, the BP complexity concept has been applied to an industrial example of Information Technology Infrastructure Library (ITIL) change management (CHM) Information Technology (IT) ticket processing. The authors used IT ticket texts from two samples of 28,157 and 4,625 tickets as the basis for the analysis.

  • ASSESSING THE POTENTIAL REPLACEMENT OF MINERAL OIL WITH ENVIRONMENTALLY ACCEPTABLE LUBRICANTS IN A STERN TUBE BEARING: AN EXPERIMENTAL ANALYSIS OF BEARING PERFORMANCE
    • Jerzy Kowalski
    • Wojciech Leśniewski
    • Daniel Piątek
    • Dominika Cuper-Przybylska
    2021 Full text Polish Maritime Research

    T his study compares the performance of a plain bearing, with a similar structure to a tail shaft stern bearing, lubricated with either mineral oil or an environmentally acceptable lubricant (EAL). The main characteristic of the bearing is its length/diameter ratio of <1. Measurements are carried out with the bearing operating under loads from 0.5 to 1 MPa and seven speeds ranging from 1 to 11 rev/s. The bearing lubricated with either mineral oil with a viscosity grade of 100 or an environmentally acceptable lubricant (EAL) with a viscosity grade of 100 or 150 is investigated according to the ISO standard. Bearing wear is simulated by increasing the clearance circle by 0.1 mm. According to the results obtained, the use of an EAL in place of mineral oil does not cause significant changes in the bearing performance, regardless of the value of the clearance radius. The pressure distribution in the oil film, bearing load carrying capacity, eccentricity and friction coefficient have similar values for the entire load and speed ranges considered, and the discrepancies in the results are within the range of the measurement errors. Only an increase in EAL viscosity causes significant changes in bearing performance and these changes comply with the general theory of lubrication.

  • Assessing the Risk in Urban Public Transport for Epidemiologic Factors
    • Marcin Budzyński
    • Aneta Łuczkiewicz
    • Jacek Szmagliński
    2021 Full text ENERGIES

    Pandemics have presented new challenges for public transport organisers and operators. New diseases (e.g., influenza H1N1, severe acute respiratory syndrome—SARS, as well as, more recently, SARS-CoV-2) increase the need for new protection measures to prevent epidemic outbreaks in public transport infrastructure. The authors’ goal is to present a set of actions in the area of public transport that are adjusted to different levels of epidemic development. The goal goes back to the following question: how can the highest possible level of passenger safety be ensured and the losses suffered by urban public transport companies kept as low as possible? The sets of pro-active measures for selected epidemic scenarios presented in the article may offer support to local authorities and public transport operators. In the next steps, it is important to develop and implement tools for public transport management to ensure safety and tackle epidemic hazards.

  • Assessment and design of greener deep eutectic solvents – A multicriteria decision analysis
    • Marta Bystrzanowska
    • Marek Tobiszewski
    2021 Full text JOURNAL OF MOLECULAR LIQUIDS

    Deep eutectic solvents (DES) are often considered as green solvents because of their properties, such as negligible vapor pressure, biodegradability, low toxicity or natural origin of their components. Due to the fact that DES are cheaper than ionic liquids, they have gained many applications in a short period of time. However, claims about their greenness sometimes seem to be exaggerated. Especially, bearing in mind lots of data gaps for DES properties as well as their individual components. To clarify the situation on their greenness status, a comprehensive assessment of commonly used hydrogen bond acceptors and donors separately and as DES is performed. The application of multicriteria decision analysis (TOPSIS ranking) with combination of biological effect modeling for DES to rank these alternatives according to greenness criteria is proposed. Also traditional organic solvents and ionic liquids as greenness reference points for better understanding are introduced. The ranking results show that many DES, which are synthetized by mixing sugars alcohols, alcohols, sugars and amides are promising environmentally friendly solvents, more than some imidazolium-based ionic liquids. Mixtures including components with metal ions and organic acids are less green.

  • Assessment of Connectivity-based Resilience to Attacks Against Multiple Nodes in SDNs
    • Dorabella Santos
    • Amaro de Sousa
    • Carmen Mas-Machuca
    • Jacek Rak
    2021 Full text IEEE Access

    In Software Defined Networks (SDNs), the control plane of a network is decoupled from its data plane. For scalability and robustness, the logically centralized control plane is implemented by physically placing different controllers throughout the network. The determination of the number and placement of controllers is known as the Controller Placement Problem (CPP). In the regular (i.e., failure-free) state, the control plane must guarantee a given maximum delay between every switch and its primary controller and a given maximum delay between every pair of controllers. In general, these delay bounds allow multiple solutions and, so, other goals can be used to determine the best CPP solution. In this paper, we assess the connectivity-based resilience to malicious attacks against multiple network nodes of the CPP solutions obtained with three different aims: the regular state delay optimization without any concern about attacks, the regular state delay optimization taking into consideration the worst-case attacks and the resilience optimization to attacks against multiple nodes. We assess the CPP solutions considering attacks of targeted nature (when the attacker has complete knowledge of the data plane) and attacks of non-targeted nature (i.e., random and epidemic attacks). We present computational results providing an analysis of the CPP solutions to the different types of attacks. The main conclusion is that the connectivity-based resilience between the different CPP solutions strongly depends on the network topology, the regular state delay bounds and the type of attacks. Finally, we provide insights on how SDN operators can consider the conducted assessment when deciding the controller placements in their networks.

  • Assessment of Corrosive Behaviour and Microstructure Characterization of Hybrid Friction Stir Welded Martensitic Stainless Steel
    • Dhanesh G. Mohan
    • S Gopi
    • Jacek Tomków
    • Shabbir Memon
    2021 Full text Advances in Materials Science

    This study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using energydispersive X-ray spectroscopy (EDX). The rate of corrosion was found out via the weight loss method in a 1 M HCL solution. The hybrid friction stir welding method used for this work is induction assisted friction stir welding; the results show that this method could produce sound AISI 410 stainless steel Joints. The experiment results show that the joint made at a spindle speed of 1150 rpm, welding speed 40 mm/min, plunge depth 0.5 mm, and in-situ heat by induction 480°C show a better corrosion resistance property with a fine grain structure.

  • Assessment of diversity and composition of bacterial community in Sludge Treatment Reed Bed systems
    • Przemysław Kowal
    • Slawomir Ciesielski
    • Martyna Godzieba
    • Karolina Fitobór
    • Magdalena Gajewska
    • Katarzyna Kołecka
    2021 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    Due to their low emission of odours and lack of the need to apply additional chemical agents, sludge treatment reed beds (STRBs) constitute an economically feasible and eco-friendly approach to sewage sludge management. Correctly designed and operated STRBs ensure effective reduction of the dry matter content coupled with the mineralisation of organic compounds. Successful operation of STRBs relies on complex interactions between the plants and microorganisms responsible for the decomposition of organic matter and nutrient cycling. While the biocenoses of wetland systems dedicated to wastewater treatment have been intensively investigated, in the case of sludge treatment applications, there is a deficit of available microbial data. The aim of this study was to explore the diversity and spatial distribution of the bacteria in three distinct STRBs which differ in maturation and feeding patterns. Analyses of the dry mass and organic matter content showed the general trend of the sludge stabilisation processes advancing through the bed depth, with the best performance in the Matured Continuous Feed (MCF) bed being noted. Samples from the MCF bed showed the statistically greatest biodiversity in relation to the other beds. Moreover, increased biodiversity of microorganisms was observed on the surface of the STRBs and the bottom zone of the MCF equipped with a passive aeration system, which proves the application of such solutions in order to enhance the performance of the process. The results of 16S rRNA gene sequencing revealed that Bacteroidetes, Proteobacteria and Firmicutes contributed approximately 80% of all identified sequences read. Network analysis revealed dominant role of Bacteroidetes in the formation of interspecies coexistence patterns. Nitrospira was the most abundant organism responsible for nitrogen metabolism in the STRBs.

  • Assessment of Fuel Cells’ State of Health by Low-Frequency Noise Measurements
    • Arkadiusz Szewczyk
    • Łukasz Gaweł
    • Kazimierz Darowicki
    • Janusz Smulko
    2021 Full text ENERGIES

    We proposed applying low-frequency (flicker) noise in proton-exchange membrane fuel cells under selected loads to assess their state of health. The measurement set-up comprised a precise data acquisition board and was able to record the DC voltage and its random component at the output. The set-up estimated the voltage noise power spectral density at frequencies up to a few hundred mHz. We observed the evolution of the electrical parameters of selected cells of different qualities. We confirmed that flicker noise intensity varied the most (more than 10 times) and preceded changes in the impedance or a drop in the output DC voltage (less than 2 times). The data were observed for current loads (from 0.5 to 32 A) far from the permissible load. We deduce that the method can be utilised in industrial conditions to monitor the state of health of the selected cells by noise analysis. The method can be used in real-time when the flicker noise is measured within the range of a few Hz and requires a reasonable amount of averaging time to estimate its power spectral density. The presented method of flicker noise measurement has considerable potential for use in innovative ways of fuel cell quality monitoring.

  • Assessment of OpenMP Master–Slave Implementations for Selected Irregular Parallel Applications
    • Paweł Czarnul
    2021 Full text Electronics

    The paper investigates various implementations of a master–slave paradigm using the popular OpenMP API and relative performance of the former using modern multi-core workstation CPUs. It is assumed that a master partitions available input into a batch of predefined number of data chunks which are then processed in parallel by a set of slaves and the procedure is repeated until all input data has been processed. The paper experimentally assesses performance of six implementations using OpenMP locks, the tasking construct, dynamically partitioned for loop, without and with overlapping merging results and data generation, using the gcc compiler. Two distinct parallel applications are tested, each using the six aforementioned implementations, on two systems representing desktop and worstation environments: one with Intel i7-7700 3.60 GHz Kaby Lake CPU and eight logical processors and the other with two Intel Xeon E5-2620 v4 2.10 GHz Broadwell CPUs and 32 logical processors. From the application point of view, irregular adaptive quadrature numerical integration, as well as finding a region of interest within an irregular image is tested. Various compute intensities are investigated through setting various computing accuracy per subrange and number of image passes, respectively. Results allow programmers to assess which solution and configuration settings such as the numbers of threads and thread affinities shall be preferred.

  • Assessment of particular abdominal aorta section extraction from contrast-enhanced computed tomography angiography
    • Tomasz Dziubich
    • Artur Skrzynecki
    • Marcin Perdeusz
    2021

    The aim of this work is to improve the accuracy of extraction of a particular abdominal aorta section and to reduce the distortion in three-dimensional Computed Tomography Angiography (CTA) images. Imaging modality and quality plays crucial role in the medical diagnostic process, thus ensuring high quality of images is essential at every stage of acquisition and processing.Noise is defined as a disturbance of the image quality that characterized by the presence of pixels that are not desired in the image. Removing or reducing the occurrence of the noise is still a challenging problem in the image processing field. We selected denoising or smoothing methods, such as Gaussian, anisotropic, Taubin, and Laplace filter. This work was carried out as a part of the aorta segmentation software which can detect and display abdominal aorta ROI. We embedded the denoising methods in the system in order to smoothen and to enhance the detection of the contour and surface of the vasculature, which subsequently leads to more accurate segmentation results and extraction particular segment of aorta. We compare the performance of method by using the aortic segmentation result represented in the form of the Dice Similarity Coefficient. Gaussian smoothing is one noise reduction technique that obtained the best in segmentation (average Dice similarity coefficient 0.9103 ±0.04. The results showed that the segmentation results presented in this work are promising, although not all the visualization was well maintained.

  • Assessment of Tensile Strength Reserve of Asphalt Mixtures at Low Temperatures
    • Marek Pszczoła
    • Cezary Szydłowski
    2021 Full text

    During winter conditions, low-temperature cracks develop at the surface of the asphalt pavement when tensile thermal stress induced in the asphalt layer during cooling equals and exceeds the tensile strength of the material. The paper presents the results of tensile strength reserve assessment of asphalt mixtures with neat and SBS-polymer modified bitumen application. The tensile strength reservewas calculated as difference between the tensile strength βt(T) obtained from the uniaxial tension stress test (UTST) and the cryogenic (thermal) stress σcry(T) obtained from the thermal stress restrained specimen test (TSRST) at the same temperature T. It can be useful factor assessing the low-temperature properties of asphalt mixtures. It was found that the highest values of tensile strength reserve were obtained for the asphalt mixture with SBS-polymer modified bitumen.

  • Assessment of the devulcanization process of EPDM waste from roofing systems by combined thermomechanical/microwave procedures
    • Xavier Colom
    • Javier Cañavate
    • Krzysztof Formela
    • Alireza Shadman
    • Mohammad Saeb
    2021 Full text POLYMER DEGRADATION AND STABILITY

    Ethylene-propylene-diene rubber (EPDM) is a elastomer widely used in common industrial applications. EPDM can be shaped into sheets and employed as isolating material for roofing systems. In this study, scraps of EPDM from commercial, industrial and residential roofing systems were treated by combined thermo-mechanical and microwave devulcanization processes including peroxide of benzoyl (BPO). The devulcanized EPDM (Dev-EPDM) was characterized by cross-link density, Horikx plot, sol fraction content, SEM and TGA analysis. In order to assess the effect of the different factors implied (type of devulcanization process, temperature and amount of BPO), the Fractional Factorial Design (FFD) method has been applied. The obtained results show that, when thermo-mechanical and microwave methods are combined, produce an intense devulcanization effect. It was also found that the presence of BPO has significative influence in the devulcanization and that the effect of the temperature is related to the amount of BPO.

  • Assessment of the factors influencing on the formation of energy-oriented modes of electric power consumption by water-drainage installations of the mines
    • Oleg Sinchuk
    • Igor Sinchuk
    • Tetyana Beridze
    • Yulii Filipp
    • Kyrylo Budnikov
    • Oleg Dozorenko
    • Ryszard Strzelecki
    2021 Full text Mining of Mineral Deposits

    Purpose. Performing the analysis to determine energy-efficient modes and assess the characteristics of the main indicators of electric power consumption by mine water-drainage installations based on the developed research mathematical model. Methods. To achieve the purpose set, a methodology is used to develop the multiple multifactor correlation-regression modeling with respect to the modes of electric power consumption by electrical and mechanical complexes of mine waterdrainage installations. The amount of consumed electric power is found as an effective feature. The expediency of using the nonlinear multiple regression analytical ratios has been substantiated during the model development. A comparative analysis of a multiple multifactor regression model, presented in the form of a power and linear function, has been performed. Findings. The expediency of using a multiple multifactor regression model in the form of a power function has been substantiated. The elaborated quantitative values of the factors of electric power consumption by electrical and mechanical complexes of mine waterdrainage installations have become the basis for the introduction of innovative technological solutions at the relevant iron ore enterprises to optimize the cost characteristics of the electric power consumption. Originality. For the first time for the analysis and assessment of the operating modes of the main water-drainage installations of mines, the use of mathematical modeling based on the multiple correlation-regression method is proposed. The developed model takes into account a complex of technological parameters of influence on the water-pumping process. The analysis of the proposed model makes it possible to identify significant factors influencing the modes of electric power consumption by electrical and mechanical complexes for constructing an algorithm for optimal control of this process in the cost-target direction. Practical implications. The analysis of the obtained results of mathematical and statistical modeling makes it possible to take into account the complex of technological parameters of the influence on the water-pumping process, to identify and assess the modes of electric power consumption by the main waterdrainage installations, as well as to obtain the initial data for the development of the structure of the control algorithm for mine stationary installations of this type in the cost-target aspect.

  • Assessment of the ice jam potential on regulated rivers and reservoirs with the use of numerical model results
    • Tomasz Kolerski
    2021 Full text COLD REGIONS SCIENCE AND TECHNOLOGY

    This study presents an attempt at estimating the jam potential on rivers with significant anthropogenic intervention in the course or flow characteristics of the river. The DynaRiCE model was used for forecasting both the place and time of an ice jam occurrence. In this modified method, two ice parameters are subjected to analysis, namely the relative ice-to-water velocity (vi/vw),and the ice thickness to single floe thickness (ηi/η0). Both variables were analyzed at two locations; first spot is the Odra River near Słubice-Frankfurt bridge (between 581 and 586 km), and the second is the Vistula section between the existing Włocławek dam (674.75 river km) and the planned Siarzewo dam (706.38 river km), covering a 31.6 km reach. Once the model is implemented in the selected areas, the numerical simulations were processed and the obtained results were analyzed in terms of ice accumulation and jamming. The results on both rivers shown some potential of ice jamming, due to the planned engineering works. In the case of the Odra river, it was indicated that ice jam potential increased during the ice run of high concentration in the average flow conditions. For the Vistula river two locations for ice jamming were designated and for both of the points an increase of the ice thickness by about 60% from the initial, single flow thickness was observed. Also in this case, the area-averaged ice velocity in an initially specified location drops below 15% of the average water velocity in that area. According to the used methodology, both cases are classified as ‘ice jam probable’ type.

  • Assessment of the Influence of Road Infrastructure Parameters on the Behaviour of Drivers and Pedestrians in Pedestrian Crossing Areas
    • Marcin Budzyński
    • Anna Gobis
    • Lucyna Gumińska
    • Łukasz Jeliński
    • Mariusz Kieć
    • Piotr Tomczuk
    2021 Full text ENERGIES

    Pedestrians are participants and, most likely, fatalities in every third road traffic accident in Poland. Over 30% of all fatalities on Polish roads are pedestrians. Accidents with pedestrians are very often the result of various factors related to the infrastructure and behaviour of pedestrians and drivers. The objective of the work was to assess driver and pedestrian behaviour in pedestrian crossing areas. The research also served as a pilot study for similar work to be conducted across Poland, and constituted the basis for monitoring the behaviour of road users in the area of pedestrian crossings. Parameters which must be analysed were identified on the basis of field studies. Principles of selecting test sites were adopted, and measurement methods for pedestrian crossing areas are presented. The influence of the location of the selected test cross-section infrastructure parameters on the behaviour of road users in pedestrian crossing areas is demonstrated. The results of the study will be used as a basis for new solutions involving pedestrian crossing infrastructure designed to improve pedestrian safety. The results were also used in formulating new regulations for the design and maintenance of pedestrian crossings and recommendations for road safety auditors.

  • Assessment of User Mobility’s Influence on System Loss in Several Body-to-Body Scenarios
    • Filipe D. Cardoso
    • Manuel M. Ferreira
    • Andrzej Ambroziak
    • Kenan Turbić
    • Luis M. Correia
    2021 Full text

    In this paper, Body-to-Body communications in indoor and outdoor environments for different on-body antenna configurations and different mobility scenarios were studied, based on system loss measurements at 2.45 GHz. The main objective is to properly characterise the influence of the Transmitter-Receiver configuration on system loss and fast fading behaviour, the latter being modelled by the Rice Distribution. Globally, it is observed that there is no significant difference on the measured average system loss between indoor and outdoor environments, but a strong dependence is seen on the configuration of the antennas and on the mobility scenario. Concerning the Rice Factor, as expected, higher values were obtained in outdoor environments, due to the lower level of multipath, the difference to the indoor case being below 4 dB, depending on the mobility environment and on the positioning of the antennas.

  • ASSESSMENT OF VOLATILE ORGANIC COMPOUNDS EMISSIONS FROM RECYCLED LOW-DENSITY POLYETHYLENE STREAMS
    • Jerzy Korol
    • Aleksander Hejna
    • Mariusz Marć
    2021 Full text

    The recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for the potential methods of their utilization. Nevertheless, it should not be forgotten that recycled plastics are not pure materials, and they still may show an unfavorable environmental impact. They may contain different contaminants accumulated during processing processes, as well as their use. Moreover, post-consumer plastics may be partially degraded due to the actions of stress, temperature, or environmental conditions. Therefore, it is imperative to investigate the actual environmental impact and eco-friendliness of recycled plastics. In the presented paper, we analyzed the volatile organic compounds emissions from recycled low-density polyethylene streams. Results indicated that the application of recycled plastics should not be indisputably considered the environmentally-friendly solution.

  • Assessment of wastewater quality indicators for wastewater treatment influent using an advanced logistic regression model
    • Bartosz Szeląg
    • Mohammad Javad Mehrani
    • Jakub Drewnowski
    • Monika Majewska
    • Grzegorz Łagód
    • Sheena Kumari
    • Faizal Bux
    2021 Desalination and Water Treatment

    Influent quality indicators play a significant role in wastewater treatment plant performance due to their correlation with reactor operations and effluent quality. However, selecting a specific/best parameter indicator for predicting influent wastewater quality is one of the challenges in wastewa- ter treatment. This study, therefore, focused on determining suitable variables as influent quality indicators. For this purpose, a logistic regression model involving different inflow parameters from two wastewater treatment plants in Poland was used to identify the best wastewater parameter as a suitable indicator for operational monitoring, process control and simulation purpose. The results showed that the model is flexible enough to simultaneously predict two or three effective waste- water quality indicators. Furthermore, the sensitivity analysis results showed a strong nonlinear relationship between the complex values of total nitrogen, total phosphorus and suspended solids.

  • Asymmetrical Modes in Polyphase Motors and Drives
    • Valentin Tomasov
    • A Usoltsev
    • Marcin Morawiec
    • Paweł Szczepankowski
    • Ryszard Strzelecki
    2021 Russian Electrical Engineering

    The effect of power supply and/or motor asymmetry on the phase-load distribution and the ripple of electromagnetic torque in a polyphase drive is studied by the method of symmetrical components. It is shown that the presence of asymmetry causes the mapping of all harmonics in the supply voltage into all planes of symmetrical components and eliminates the possibility of independent control of harmonics. The dynamic model of a five-phase squirrel-cage induction motor demonstrates that even minor phase or amplitude asymmetry causes asymmetry in the phase load and ripple of the electromagnetic torque. Their level eliminates the possibility of continuous operation of the motor in this mode and requires the use of control systems that provide load balance in the intact phases.

  • Atmospheric deposition of microplastics in the coastal zone: Characteristics and relationship with meteorological factors
    • Karolina Szewc
    • Bożena Graca
    • Anna Dołęga
    2021 SCIENCE OF THE TOTAL ENVIRONMENT

    The quantitative and qualitative compositions of microplastics (MPs) deposited from the atmosphere in the coastal zone were analysed. Moreover, links between MP deposition and meteorological factors (air humidity, wind speed, precipitation height, and air mass trajectories) were investigated

  • Atom-economic thiophosphoroselenenylations of C–H acid esters and amides
    • Arkadiusz Majewski
    • Witold Przychodzeń
    2021 Full text SYNTHETIC COMMUNICATIONS

    Three improved thiophosphoroselenenylation procedures of CHacids, including derivatives of malonic and acetyl-, phosphono-, 4-nitrophenyl- and 3-pyridylacetic acids, have been described and compared to previously reported thiophosphoroselenylation of diethyl malonate using bis(disopropoxyphosphinothioyl)diselenide alone or with the aid of methyl iodide. The use of iodine makes it possible to utilize both equivalents of the selenenylating agent. The procedures work well for the majority of nucleophiles in a pKa range between more acidic malononitrile or Meldrum acid and less acidic phenylacetates. The reaction carried out on diethyl malonate in boiling rectified ethanol yields selenoacetate, which cannot be obtained by direct phosphoroselenenylation. Crystal structure of one of the selenomalonamides confirms the stabilization effects of both carbonyl oxygens on selenium atom. The P-Se bond splitting, using TBAF in 3-molar excess in the presence of alkylating agent yields the respective C,Se-dialkyl derivatives.

  • Automatic Identification System (AIS) Dynamic Data Integrity Monitoring and Trajectory Tracking Based on the Simultaneous Localization and Mapping (SLAM) Process Model
    • Krzysztof Jaskólski
    • Łukasz Marchel
    • Andrzej Felski
    • Marcin Jaskólski
    • Mariusz Specht
    2021 Full text SENSORS

    To enhance the safety of marine navigation, one needs to consider the involvement of the automatic identification system (AIS), an existing system designed for ship-to-ship and shipto- shore communication. Previous research on the quality of AIS parameters revealed problems that the system experiences with sensor data exchange. In coastal areas, littoral AIS does not meet the expectations of operational continuity and system availability, and there are areas not covered by the system. Therefore, in this study, process models were designed to simulate the tracking of vessel trajectories, enabling system failure detection based on integrity monitoring. Three methods for system integrity monitoring, through hypotheses testing with regard to differences between model output and actual simulated vessel positions, were implemented, i.e., a Global Positioning System (GPS) ship position model, Dead Reckoning and RADAR Extended Kalman Filter (EKF)—Simultaneous localization and mapping (SLAM) based on distance and bearing to navigational aid. The designed process models were validated on simulated AIS dynamic data, i.e., in a simulated experiment in the area of Gda´nsk Bay. The integrity of AIS information was determined using stochastic methods based on Markov chains. The research outcomes confirmed the usefulness of the proposed methods. The results of the research prove the high level (~99%) of integrity of the dynamic information of the AIS system for Dead Reckoning and the GPS process model, while the level of accuracy and integrity of the position varied depending on the distance to the navigation aid for the RADAR EKF-SLAM process model.

  • Automation of the Road Gate Operations Process at the Container Terminal—A Case Study of DCT Gdańsk SA
    • Karol Moszyk
    • Mariusz Deja
    • Michał Dobrzyński
    2021 Full text Sustainability

    The future increased terminal capacity will result in more container movement through the road complex and rail siding, which are one of the most critical areas (potential bottlenecks) in the container terminal. Truck turnaround time is one of the major factors that customers take into account while deciding how many container volumes they will handle through the container terminal. To enable to optimize increased traffic with future container terminal development, as well as increase gates throughput, and as a consequence, encourage more volume and increase customer satisfaction, Deepwater Container Terminal Gdańsk SA plans to reorganize and automatize Gate Operation Process. Gate Automation includes supply, installation, commissioning, implementation, and maintenance of software and hardware that would allow automatizing the handling of trucks at container terminal gates by using OCR (Optical Camera Recognition) technology, LPR (License Plate Recognition) systems and self-service kiosk for truck drivers.

  • AUTOMATYCZNE GENEROWANIE KOLEJNOŚCI LIST UTWORÓW MUZYCZNYCH
    • Kamila Pietrusińska
    • Adam Kurowski
    • Bożena Kostek
    2021

    W niniejszym rozdziale przedstawiono przygotowanie algorytmu do automa-tycznego układania kolejności utworów muzycznych i zgrywającego je do postaci jednego, długiego miksu. Dzięki algorytmowi dobierane są utwory na podstawie analizy podobieństwa fragmentów końcowych i początkowych utworów. Podo-bieństwo to jest obliczane za pomocą odległości euklidesowej między wektorami parametrów wyznaczonymi przez autoenkoder oraz na podstawie analizy skupień (data clustering). Taki sposób ułożenia utworów umożliwia zapewnienie ciągłości listy. Jakość wyników jest weryfikowana z zastosowaniem testów odsłuchowych przez porównanie automatycznie generowanych list z listami ułożonymi w sposób losowy.

  • Automatyzacja procesów produkcji spiekanych kompozytów diamentowo-metalowych.
    • Andrzej Bakoń
    • Adam Barylski
    2021 Materiały & Maszyny Technologiczne

    Przedstawiono technologie produkcji narzędzi diamentowych o spoiwach metalowych spiekanych. Na podstawie własnych doświadczeń oraz kontaktów z wytwórcami takich narzędzi i firmami oferującymi urządzenia do ich produkcji dokonano przeglądu stosowanych technologii wytwarzania pod katem ich automatyzacji.

  • Axial capacity of steel built-up battened columns
    • Paweł Pieczka
    • Piotr Iwicki
    2021

    This paper deals with the numerical investigation aimed to study the axial capacity of pin-ended steel built-up columns. Three methods of calculating forces in chords and batten, taking into account the material and geometric imperfections specified in the Eurocode 3 are considered. The aim of this study was to compare different methods allowing the calculation of the column load capacity and determine a simpler and faster method than the present Eurocode 3 procedure related to design of built up members. In the paper, the method according to Eurocode 3 for uniform built-up compression member and the method according to PN-B-03200:1990 are compared with the code method for the structure modeled as separate members for column chords and battens. Calculations were carried out for the column modeled by 1D-beam elements and for a whole shell model of the column. Finite element (FE) models were established and verified against the built-up columns with similar configurations that were tested experimentally in the studies presented in the literature, and then compared with the calculations specified in Eurocode 3.

  • Bacteriophages as potential tools for use in antimicrobial therapy and vaccine development
    • Beata Zalewska-Piątek
    • Rafał Piątek
    2021 Full text Pharmaceuticals

    The constantly growing number of people suffering from bacterial, viral, or fungal infections, parasitic diseases, and cancers prompts the search for innovative methods of disease prevention and treatment, especially based on vaccines and targeted therapy. An additional problem is the global threat to humanity resulting from the increasing resistance of bacteria to commonly used antibiotics. Conventional vaccines based on bacteria or viruses are common and are generally effective in preventing and controlling various infectious diseases in humans. However, there are problems with the stability of these vaccines, their transport, targeted delivery, safe use, and side effects. In this context, experimental phage therapy based on viruses replicating in bacterial cells currently offers a chance for a breakthrough in the treatment of bacterial infections. Phages are not infectious and pathogenic to eukaryotic cells and do not cause diseases in human body. Furthermore, bacterial viruses are sufficient immuno-stimulators with potential adjuvant abilities, easy to transport, and store. They can also be produced on a large scale with cost reduction. In recent years, they have also provided an ideal platform for the design and production of phage-based vaccines to induce protective host immune responses. The most promising in this group are phage-displayed vaccines, allowing for the display of immunogenic peptides or proteins on the phage surfaces, or phage DNA vaccines responsible for expression of target genes (encoding protective antigens) incorporated into the phage genome. Phage vaccines inducing the production of specific antibodies may in the future protect us against infectious diseases and constitute an effective immune tool to fight cancer. Moreover, personalized phage therapy can represent the greatest medical achievement that saves lives. This review demonstrates the latest advances and developments in the use of phage vaccines to prevent human infectious diseases; phage-based therapy, including clinical trials; and personalized treatment adapted to the patient’s needs and the type of bacterial infection. It highlights the advantages and disadvantages of experimental phage therapy and, at the same time, indicates its great potential in the treatment of various diseases, especially those resistant to commonly used antibiotics. All the analyses performed look at the rich history and development of phage therapy over the past 100 years.

  • Badania architektoniczne Twierdzy Wisłoujście w Gdańsku. Etap III: wnętrza Wieńca
    • Piotr Samól
    • Arkadiusz Woźniakowski
    • Robert Hirsch
    2021

    Badania architektoniczne dotyczyły Wieńca w Twierdzy Wisłoujście. Stanowiły uzupełnienie rozwarstwień Wieńca w zakresie planu budowli.

  • Badania nad docieraniem płaskich elementów ceramicznych z wymuszonym dawkowaniem zawiesiny ściernej
    • Adam Barylski
    • Maciej Gniot
    2021

    W pracy przedstawiono zagadnienia dotyczące obróbki wykończeniowej płaskich uszczelnień ceramicznych. Wymagania obróbkowe stawiane tego typu elementom sprawiają, że konieczne jest zastosowanie docierania w procesie technologicznym. Tego typu bardzo dokładna obróbka ścierna powierzchni płaskich wymaga użycia odpowiedniej zawiesiny lub pasty ściernej. Na wynik obróbki ma wpływ wiele czynników związanych z metalową tarczą docierającą, składnikami zawiesiny ściernej i warunkami technologicznymi obróbki. Decydujące znaczenie ma też sposób i intensywność dawkowania zawiesiny w strefę docierania. Standardowy swobodny sposób dawkowania - w sposób ciągły, najczęściej zalewowo lub kroplowo, powoduje duże straty ścierniwa. Część mikroziaren ściernych zostaje szybko usunięta z powierzchni roboczej tarczy docierającej przez obracające się pierścienie prowadzące separatory z obrabianymi elementami i nie bierze w ogóle udziału w skrawaniu. Opracowany innowacyjny układ jest przystosowany do pracy na docierarce Abralap 380. W artykule opisano zalety takiego systemu dawkowania zawiesiny ściernej oraz sposób postępowania podczas planowania badań docierania elementów płaskich z ceramiki technicznej na przykładzie Al2O3. Zaprezentowano wybrane wyniki badań ubytku elementów, które następnie poddano analizie statystycznej.