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Gdańsk University of Technology

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  • Detection of anomalies in bee colony using transitioning state and contrastive autoencoders
    • Tymoteusz Cejrowski
    • Julian Szymański
    2022 Full text COMPUTERS AND ELECTRONICS IN AGRICULTURE

    Honeybees plays vital role for the environmental sustainability and overall agricultural economy. Assisting bee colonies within their proper functioning brings the attention of researchers around the world. Electronics systems and machine learning algorithms are being developed for classifying specific undesirable bee behaviors in order to alert about upcoming substantial losses. However, classifiers could be impaired when used for general honeybee colony state inference. Application of the classifier models for the hazardous situations detection without focusing on the model’s genericity could result with systems that are not applicable in the real environment. Furthermore, the detection of a specific phenomenon does not provide researchers with any new conclusions about the honeybee colony life but only with the binary information about hazardous situation presence. In our research we propose a method for inferring the bee colony state using a sensitive contrastive autoencoder and an anomaly detection model. With presented approach, hive’s internal state is modeled with the use of an autoencoder’s latent vector extended with in-hive temperature dynamics. We test our methodology with a bee feeding experiment where the glucose syrup application was detected and the length of food intake was estimated. As our methodology has been applied successfully, we argue that contrastive autoencoders can be used for precise inference about the behavior of honeybees.

  • Detection of Anomalies in the Operation of a Road Lighting System Based on Data from Smart Electricity Meters
    • Tomasz Śmiałkowski
    • Andrzej Czyżewski
    2022 Full text ENERGIES

    Smart meters in road lighting systems create new opportunities for automatic diagnostics of undesirable phenomena such as lamp failures, schedule deviations, or energy theft from the power grid. Such a solution fits into the smart cities concept, where an adaptive lighting system creates new challenges with respect to the monitoring function. This article presents research results indicating the practical feasibility of real‐time detection of anomalies in a road lighting system based on analysis of data from smart energy meters. Short‐term time series forecasting was used first. In addition, two machine learning methods were used: one based on an autoregressive integrating moving average periodic model (SARIMA) and the other based on a recurrent network (RNN) using long short‐term memory (LSTM). The algorithms were tested on real data from an extensive lighting system installation. Both approaches enable the creation of self‐learning, real‐time anomaly detection algorithms. Therefore, it is possible to implement them on edge computing layer devices. A comparison of the algorithms indicated the advantage of the method based on the SARIMA model.

  • Determinants and effects of Poland’s road accidents in the context of the 2030 agenda for sustainable development – poviat level analysis for the years 2010-2019
    • Aleksandra Romanowska
    • Sylwia Pangsy-Kania
    • Marcin Budzyński
    • Katarzyna Wierzbicka
    • Joanna Prystrom
    2022 Full text Ekonomia i Środowisko

    The objective of the research was to assess how selected factors influence road safety in Poland’s poviats. To that end, an analysis was conducted of road accident determinants and effects in the poviats in the years 2010-2019. The time horizon fits in with Goal 3.6. of Agenda 2030, which is to halve the number of global deaths and injuries from road traffic accidents by 2020. The article pres-ents the analysis results for the following determinants: the rate of car ownership by poviat, poviat spending on transport and length of the road network, and quality of road infrastructure. The research problem was to establish which of the poviats are closest to achieving Goal 3.6. of Agenda 2030 and how likely it is, and, as a consequence, which of the poviats should step up their road safety policies to align them to the targets set out in the Agenda. To identify groups of poviats sharing similar character-istics, they were grouped using the k-means method. Five groups of poviats were identified and analysed for how their road safety indicators changed between 2010 and 2019. The results of the analysis show that the highest fatality reduction (-40%) was achieved by urban poviats with the highest per capita spending on transport. The same poviats, however, have the highest increases in serious inju-ries (+30%). The analyses show that Polish poviats are still far from achieving Goal 3.6 of Agenda 2030. The research results presented in the article are original for the poviat level

  • Determinants of Directionality and Efficiency of the ATP Synthase Fo Motor at Atomic Resolution
    • Antoni Marciniak
    • Paweł Chodnicki
    • Kazi Hossain
    • Joanna Słabońska
    • Jacek Czub
    2022 Full text Journal of Physical Chemistry Letters

    Fo subcomplex of ATP synthase is a membrane-embedded rotary motor that converts proton motive force into mechanical energy. Despite a rapid increase in the number of high-resolution structures, the mechanism of tight coupling between proton transport and motion of the rotary c-ring remains elusive. Here, using extensive all-atom free energy simulations, we show how the motor’s directionality naturally arises from the interplay between intraprotein interactions and energetics of protonation of the c-ring. Notably, our calculations reveal that the strictly conserved arginine in the a-subunit (R176) serves as a jack-of-all-trades: it dictates the direction of rotation, controls the protonation state of the proton-release site, and separates the two proton-access half-channels. Therefore, arginine is necessary to avoid slippage between the proton flux and the mechanical output and guarantees highly efficient energy conversion. We also provide mechanistic explanations for the reported defective mutations of R176, reconciling the structural information on the Fo motor with previous functional and single-molecule data.

  • Determinants of judges’ career choices and productivity: a Polish case study
    • Przemysław Banasik
    • Katarzyna Metelska-Szaniawska
    • Małgorzata Godlewska
    • Sylwia Morawska
    2022 Full text European Journal of Law and Economics

    The goal of this paper is to identify factors which affect judges’ productivity and career choice motives with the view of increasing judicial efficiency. Specifically, the investigation focuses on such aspects as judges’ remuneration, promotion, threat of judgment revocation, service/mission, periodic assessment, the threat of a complaint about protracted proceedings or of disciplinary proceedings, the threat of destabilization of the employment relationship, status/prestige of the profession, power/authority, social recognition, leisure, as well as administrative supervision and self-monitoring. To this end, a survey was conducted among judges of three of the largest Polish regional courts and subordinate district courts. The descriptive and statistical analyses show that judges’ care for the number of cases resolved, proxying for their productivity, is significantly correlated with self-monitoring of their adjudication activity. The stability of employment, the status/prestige of the profession and a relatively high remuneration are the most important factors in terms of judges’ career choices. In their care for the number of cases resolved remuneration is, albeit, no longer a relevant factor. Judges monitor their productivity due to reasons other than remuneration, possibly the sense of service/mission and the threat of various adverse consequences, the evidence for which is, however, also rather weak.

  • DETERMINANTY (NIE)PRZEJRZYSTOŚCI FINANSÓW SAMORZĄDOWYCH
    • Maria Jastrzębska
    2022 Full text Optimum. Studia Ekonomiczne

    Cel – Celem artykułu jest identyfikacja determinant przejrzystości finansów samorządowych oraz wskazanie, które z nich pozytywnie i negatywnie oddziałują na jej poziom, ze szczególnym uwzględnieniem sytuacji w Polsce. Metody – Artykuł ma charakter teoretyczny, jest oparty na przeglądzie literatury przedmiotu z zakresu ekonomii i finansów, organizacji i zarządzania oraz socjologii. Wykorzystano metodę analizy deskryptywnej oraz komparatywnej. Wyniki – Rola sprawozdawczości jednostki samorządu terytorialnego jako źródła użytecznej informacji oraz przepływ informacji o stanie finansów samorządowych i stanie majątku komunalnego między władzą samorządową a mieszkańcami są ograniczone. Częste zmiany regulacji prawa finansów samorządowych zwiększają ich nieprzejrzystość. Centralizacja finansów publicznych zmniejsza samodzielność finansową samorządu terytorialnego i negatywnie wpływa na przejrzystość jego finansów. Oryginalność/wartość/implikacje/rekomendacje – Badania w zakresie oceny przejrzystości finansów samorządowych w Polsce są podejmowane rzadko. W niniejszym artykule zwrócono uwagę na podejście podażowe i popytowe do przejrzystości finansów samorządowych. Zidentyfikowano determinanty przejrzystości finansów jednostek samorządu terytorialnego w ich otoczeniu dalszym (makrootoczeniu): społeczno-kulturowe, polityczno-prawne, ekonomiczne oraz w otoczeniu bliższym (mikrootoczeniu): instytucjonalne.

  • Determination of Changes in Viscosity of Hydrogel Depending on Shear Rates
    • Szymon Mania
    • Robert Tylingo
    • Katarzyna Kozłowska-Tylingo
    2022 Full text

    The datasets entitled Determination of changes in viscosity of hydrogel depending on shear rate contain the results of viscosity measurements using a Brookfield viscometer, with different kinds of spindles and shear rates. The data allowed the used hydrogel preparations to be characterised and their functional parameters, as substances modifying the rheology of thickeners and determining the effect of shear rate on the viscosity of hydrogels, to be assessed.

  • Determination of Heavy Metals Concentration in Water and Soil at Various Locations in Lahore and their Harmful Impacts on Human and Plants life
    • Ayesha Noreen
    • Sajid Hussain
    • Umar Farooq
    • Younas Tasaddaq
    • Rahid Khan
    • Gamal Mohamed
    2022 Full text Pakistan Journal of Medical & Health Sciences

    Heavy metals poisoning of soil and water has resulted from industrial expansion in Lahore, Pakistan, creating a significant environmental hazard. As a result, monitoring the contamination of soil and water around industrial sites is critical. The fact that higher concentrations of heavy metals have a negative influence on both plants and human life and this cannot be ignored. Higher heavy metal concentrations have a direct impact on human health due to their presence in drinking water. Consumable plants and vegetables cultivated in these polluted areas may collect higher concentrations of heavy metals from soil and water via the phytoremediation process. Its worth mentioning that the accumulation of toxic metals in edible plants and vegetables also has a direct negative impact on human and animal health. The purpose of this study is to find the heavy metals concentration in the soil and ground water in the Lahore area. Five industrial zones were evaluated for water and soil throughout the research period of December 2021 to January 2022 (pre-monsoon). pH and heavy metals content measurements were performed on the collected soil and water samples. We discovered that the water had a higher pH and that the soil was heavily contaminated with significantly higher concentrations of toxic heavy metals. According to the research, there is a gangrenous influence of pollution caused by industrial waste and the surrounding environment on soil and water resources, which affects living creatures.

  • Determination of Odor Air Quality Index (OAQII) Using Gas Sensor Matrix
    • Dominik Dobrzyniewski
    • Bartosz Szulczyński
    • Jacek Gębicki
    2022 Full text MOLECULES

    This article presents a new way to determine odor nuisance based on the proposed odor air quality index (OAQII), using an instrumental method. This indicator relates the most important odor features, such as intensity, hedonic tone and odor concentration. The research was conducted at the compost screening yard of the municipal treatment plant in Central Poland, on which a self-constructed gas sensor array was placed. It consisted of five commercially available gas sensors: three metal oxide semiconductor (MOS) chemical sensors and two electrochemical ones. To calibrate and validate the matrix, odor concentrations were determined within the composting yard using the field olfactometry technique. Five mathematical models (e.g., multiple linear regression and principal component regression) were used as calibration methods. Two methods were used to extract signals from the matrix: maximum signal values from individual sensors and the logarithm of the ratio of the maximum signal to the sensor baseline. The developed models were used to determine the predicted odor concentrations. The selection of the optimal model was based on the compatibility with olfactometric measurements, taking the mean square error as a criterion and their accordance with the proposed OAQII. For the first method of extracting signals from the matrix, the best model was characterized by RMSE equal to 8.092 and consistency in indices at the level of 0.85. In the case of the logarithmic approach, these values were 4.220 and 0.98, respectively. The obtained results allow to conclude that gas sensor arrays can be successfully used for air quality monitoring; however, the key issues are data processing and the selection of an appropriate mathematical model.

  • Determination of phenylbutazone, sulfamethazine, carbendazim and linuron using a novel pine bark biosorbent for solid-phase extraction (SPE) with high-performance liquid chromatography (HPLC)
    • Hassen Khazri
    • Grzegorz Boczkaj
    • Ibtissem Ghorbel-Abid
    • Malika Trabelsi-Ayadi
    2022 INSTRUMENTATION SCIENCE & TECHNOLOGY

    The paper presents a novel pine bark based biosorbent for solid-phase extraction (SPE). The morphology and composition of the pine bark were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The biosorbent was used for the preparation of wastewater for the determination of phenylbutazone, sulfamethazine, carbendazim, and linuron by high performance liquid chromatography with ultraviolet detection (HPLC-UV). The SPE conditions were optimized with respect to elution solvent, sample volume, and extraction pH. The results showed that developed sorbent provides good repeatability. The relative standard deviation (n = 3), was between 0.3 and 2.2%. The limits of detection (LOD) were between 0.11 and 0.4 µg.L−1. The developed method was used for determination of the analytes in effluent from a wastewater treatment plant.

  • Determination of stepped plate thickness distribution using guided waves and compressed sensing approach
    • Beata Zima
    2022 Full text MEASUREMENT

    Guided waves recently have attracted significant interest as a very promising research area. The signals registered by a specially designed sensor network are processed to assess the state of the tested structure. Despite the constant development of novel damage detection algorithms employing guided waves, the phenomenon of wave propagation still needs detailed recognizing and understanding for the further progress of non-destructive wave-based methods. Special attention is paid to guided waves in plate-like structures, but the majority of considered cases concern plates with constant thickness. However, in the real world, we often deal with specimens with variable thickness. The thickness variability of the specimen is often forced to fulfill the construction requirements and optimize stress distribution or is the result of degradation i.e. corrosion. Thus, the development of NDT methods forces the need of considering specimens with complex geometry and the problem of wave propagation in waveguides with variable thickness is crucial for improving novel as well as so far proposed algorithms. The article presents the results of the analytical, numerical and experimental analysis of wave propagation in plates with variable thickness. The analysis concerns the influence of thickness distribution of plate structure on wave velocity, the time course wave packet and amplitude. Moreover, the novel approach based on constrained convex optimization for determining the plate thickness distribution has been proposed and verified during numerical and experimental campaigns.

  • Determination of vertical displacements by using the hydrostatic levelling systems with the variable location of the reference sensor,
    • Waldemar Kamiński
    2022 Full text Archives of Civil Engineering

    Abstract: In this paper, the author proposed a new method for determination of vertical displacements with the use of hydrostatic levelling systems. The traditional method of hydrostatic levelling uses a rule in which a position of reference sensor is stable. This assumption was not adapted in the proposed method. Regarding the issue mentioned above, the reference sensor is treated in the same way as the others sensors that measure the liquid level. As a consequence of this approach there is a possibility of vertical displacement determination of both the reference sensor as well as the remaining controlled sensors. A theoretical considerations were supplemented with the practical examples. The possibility of calculating the vertical displacement of reference sensor is an undoubted advantage of the submitted proposal. This information enables more detailed interpretation of the vertical displacements results obtained from hydrostatic levelling systems. Thus, wider knowledge about maintenance of the entire examined object treated as the rigid body is obtained. The tests that were carried out confirm the theoretical assumptions and encourage to perform further, more precise empirical analyses.

  • Deterministic versus stochastic modelling of unsaturated flow in a sandy field soil based on dual tracer breakthrough data
    • Gunnar Nützmann
    • Stanislaw Maciejewski
    • Wioletta Gorczewska-Langner
    2022 Full text GEOLOGICAL QUARTERLY

    The 216 km2 Neuenhagen Millcreeck catchment can be characterized as a drought sensitive landscape in NE Germany. It is therefore a fundamental human interest to understand how water that fell as precipitation moves through the unsaturated soils and recharges groundwater. Additionally, a better knowledge of nutrient transport from soil to groundwater is important also, especially in landscapes with light sandy soils. For a better understanding of these processes a dual tracer field experiment with bromide (Br-) and deuterium (D2O) was carried out years ago. The aim of the present study is to use results of these data for modelling tracer transport in the unsaturated zone with two different concepts, the classical deterministic advection – dispersion equation and a new stochastic approach. The advantage of the stochastic modelling method proposed here for field scale tracer application is to produce reliable information about expected total solute fluxes from the unsaturated zone to groundwater or mean transit times. Moreover, this allows one to evaluate the mass of solute in the soil profile and to determine the range of water velocity fluctuations. Field experiments should be concentrated on estimation of fluctuation of water flow velocity to make stochastic models more accurate. To summarize, this work contributes to new modelling methods for simulation of water and solute transport in unsaturated sandy soils which are heavily affected by droughts and irregular hydrological processes in the subsurface.

  • Developing Polycentricity to Shape Resilient Metropolitan Structures: The Case of the Gdansk–Gdynia–Sopot Metropolitan Area
    • Piotr Lorens
    • Anna Golędzinowska
    2022 Full text Urban Planning

    Making the metropolitan area resilient, in many cases, calls for amending its spatial structures. This may take various forms, including both reshaping the metropolitan core and redeveloping the entire regional network of cities and centres, making them part of a coherent structure. The latter strategy is associated with reinforcing secondary urban centres as well as shaping new connections between them. In this case, the term “resilience” is associated not only with environmental aspects but also with socio‐economic and spatial ones. Shaping resilient metropolitan areas is therefore associated with complex planning and development undertakings, in many cases spread over decades. This approach was proven to be correct during the recent Covid‐19 pandemic, which spurred this process of rethinking metropolitan structures and led to generating new approaches to metropolitan development and planning. The article focuses on the Gdansk–Gdynia– Sopot Metropolitan Area, which is potentially the largest polycentric metropolitan area on the southern shore of the Baltic Sea. In this case, polycentricity has a twofold origin—it includes centres with a shaped spatial structure that come closer together as they develop and diffuse suburban structure, the shaping of which remains one of the main challenges of the regional spatial policy. The authors look at both concepts and tools associated with reshaping this metropolitan centre. In particular, they analyse the effects of using both obligatory and optional planning tools which are available according to Polish law. They also try to answer the question of under what conditions a polycentric structure has a chance to become a resistant structure.

  • Developing the Urban Blue-Green Infrastructure as a Tool for Urban Air Quality Management
    • Joanna Badach
    • Jakub Szczepański
    • Wojciech Bonenberg
    • Jacek Gębicki
    • Lucyna Nyka
    2022 Full text Sustainability

    Urban structure is an important factor that shapes the process of urban ventilation and pollution dispersion. With proper planning of the urban spatial layout, city breathability can be effectively regulated, contributing to urban air quality improvement. This paper investigates the development and current management of urban systems of green and open spaces in four Polish cities: Gda ´nsk, Warsaw, Pozna ´n and Wrocław, with a particular focus on the planning aspects of urban ventilation and air quality management. The initial GIS-based comparison of historical plans and the current spatial layouts of the cities show that these systems, consciously shaped at the beginning of the twentieth century, remain clearly identifiable. However, in some locations, the continuance of these systems was interrupted by later investments. The next step was to develop GIS procedures to effectively map the spatial distribution of selected urban form indicators that are related to urban ventilation, especially the frontal area index. The results made it possible to determine the main features of the current ventilation systems and to identify some of the local problem areas. The last phase of the study was to conduct a local-scale analysis of these problem areas. With this study, the applicability of various analysis and simulation tools for the purpose of improving city breathability by appropriate integrated planning and design decisions was demonstrated. The presented approach, taking into account the city- and micro-scale interactions, should be used in current planning practice to preserve the historically developed ventilation systems.

  • Development and Assessment of Regeneration Methods for Peptide-Based QCM Biosensors in VOCs Analysis Applications
    • Tomasz Wasilewski
    • Bartosz Szulczyński
    • Dominik Dobrzyniewski
    • Weronika Jakubaszek
    • Jacek Gębicki
    • Wojciech Kamysz
    2022 Full text Biosensors-Basel

    Cleaning a quartz crystal microbalance (QCM) plays a crucial role in the regeneration of its biosensors for reuse. Imprecise removal of a receptor layer from a transducer’s surface can lead to unsteady operation during measurements. This article compares three approaches to regeneration of the piezoelectric transducers using the electrochemical, oxygen plasma and Piranha solution methods. Optimization of the cleaning method allowed for evaluation of the influence of cleaning on the surface of regenerated biosensors. The effectiveness of cleaning the QCM transducers with a receptor layer in the form of a peptide with the KLLFDSLTDLKKKMSEC-NH2 sequence was described. Preliminary cleaning was tested for new electrodes to check the potential impact of the cleaning on deposition and the transducer’s operation parameters. The effectiveness of the cleaning was assessed via the measurement of a resonant frequency of the QCM transducers. Based on changes in the resonant frequency and the Sauerbrey equation, it was possible to evaluate the changes in mass adsorption on the transducer’s surface. Moreover, the morphology of the QCM transducer’s surface subjected to the selected cleaning techniques was presented with AFM imaging. The presented results confirm that each method is suitable for peptide-based biosensors cleaning. However, the most invasive seems to be the Piranha method, with the greatest decrease in performance after regeneration cycles (25% after three cycles). The presented techniques were evaluated for their efficiency with respect to a selected volatile compound, which in the future should allow reuse of the biosensors in particular applications, contributing to cost reduction and extension of the sensors’ lifetime.

  • Development and performance analysis of a novel multiphase doubly-fed induction generator
    • Roland Ryndzionek
    • Krzysztof Blecharz
    • Filip Kutt
    • Michał Michna
    • Grzegorz Kostro
    2022 Full text Archives of Electrical Engineering

    This paper presents the research into the design and performance analysis of a novel five-phase doubly-fed induction generator (DFIG). The designed DFIG is developed based on standard induction motor components and equipped with a five-phase rotor winding supplied from the five-phase inverter. This approach allows the machine to be both efficient and reliable due to the ability of the five-phase rotor winding to operate during single or dual-phase failure. The paper presents the newly designed DFIG validation and verification based on the finite element analysis (FEA) and laboratory tests.

  • Development of a Response Assessment Tool for a Floating Dock System
    • Jianan Zhang
    • Lin Li
    • Muk Chen Ong
    • Omar El Beshbichi
    • Aleksander Kniat
    2022

    Docking operations of ships require a response assessment to ensure structural and personnel safety. Environmental loads and improper ballast adjustments are the main threats to the docking operations. They can cause severe structural damages and stability loss to a floating dock system which includes a floating dock and a docked vessel, even if the velocities of the dock and the vessel are very low during the docking process. Response assessment of the floating dock system, including structural strength analysis and stability check, needs to be performed for a safe docking operation. This paper aims to propose a framework of a floating dock system’s response assessment. The stages of ship docking operations are firstly described. The environmental and operational risks involved in those stages are discussed in detail. Then, relevant studies on the structural strength assessment and stability analysis of floating docks are reviewed. Based on the review, a framework to perform a response assessment of a floating dock system is proposed and discussed with a focus on the dynamic response analysis. A numerical model of the dynamic response assessment is established using the language Modelica. A preliminary case study of a single dock under pure wave conditions is presented.

  • Development of an AI-based audiogram classification method for patient referral
    • Michał Kassjański
    • Marcin Kulawiak
    • Tomasz Przewoźny
    2022

    Hearing loss is one of the most significant sensory disabilities. It can have various negative effects on a person's quality of life, ranging from impeded school and academic performance to total social isolation in severe cases. It is therefore vital that early symptoms of hearing loss are diagnosed quickly and accurately. Audiology tests are commonly performed with the use of tonal audiometry, which measures a patient's hearing threshold both in air and bone conduction at different frequencies. The graphic result of this test is represented on an audiogram, which is a diagram depicting the values of the patient's measured hearing thresholds.In the course of the presented work several different artificial neural network models, including MLP, CNN and RNN, have been developed and tested for classification of audiograms into two classes - normal and pathological represented hearing loss. The networks have been trained on a set of 2400 audiograms analysed and classified by professional audiologists. The best classification performance was achieved by the RNN architecture (represented by simple RNN, GRU and LSTM), with the highest out-of-training accuracy being 98\% for LSTM. In clinical application, the developed classifier can significantly reduce the workload of audiology specialists by enabling the transfer of tasks related to analysis of hearing test results towards general practitioners. The proposed solution should also noticeably reduce the patient's average wait time between taking the hearing test and receiving a diagnosis. Further work will concentrate on automating the process of audiogram interpretation for the purpose of diagnosing different types of hearing loss.

  • Development of cluster analysis methodology for identification of model rainfall hyetographs and its application at an urban precipitation field scale
    • Karol Mikołajewski
    • Marek Ruman
    • Klaudia Kosek
    • Marcin Glixelli
    • Paulina Dzimińska
    • Piotr Ziętara
    • Paweł Licznar
    2022 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    Despite growing access to precipitation time series records at a high temporal scale, in hydrology, and particularly urban hydrology, engineers still design and model drainage systems using scenarios of rainfall temporal distributions predefined by means of model hyetographs. This creates the need for the availability of credible statistical methods for the development and verification of already locally applied model hyetographs. The methodology development for identification of similar rainfall models is also important from the point of view of systems controlling stormwater runoff structure in real time, particularly those based on artificial intelligence. This paper presents a complete methodology of division of storm rainfalls sets into rainfalls clusters with similar temporal distributions, allowing for the final identification of local model hyetographs clusters. The methodology is based on cluster analysis, including the hierarchical agglomeration method and k-means clustering. The innovativeness of the postulated methodology involves: the objectivization of clusters determination number based on the analysis of total within sum of squares (wss) and the Caliński and Harabasz Index (CHIndex), verification of the internal coherence and external isolation of clusters based on the bootmean parameter, and the designated clusters profiling. The methodology is demonstrated at a scale of a large urban precipitation field of Kraków city on a total set of 1806 storm rainfalls from 25 rain gauges. The obtained results confirm the usefulness and repeatability of the developed methodology regarding storm rainfall clusters division, and identification of model hyetographs in particular clusters, at a scale of an entire city. The applied methodology can be successfully transferred on a global scale and applied in large urban agglomerations around the world.

  • Development of fragility curves in adjacent steel moment-resisting frames considering pounding effects through improved wavelet-based refined damage-sensitive feature
    • Omid Yazdanpanah
    • Benyamin Mohebi
    • Farzin Kazemi
    • Iman Mansouri
    • Robert Jankowski
    2022 MECHANICAL SYSTEMS AND SIGNAL PROCESSING

    Fragility curves present useful information related to earthquake-induced probability assessment ‎of steel moment-resisting frames (MRFs) and determine the probability of the damage ‎exceedance at different floor levels of MRFs. The review of the literature shows that most of the ‎previous studies dealing with the fragility curves were based on conventional measures, such as ‎spectral acceleration at the first mode period, peak ground acceleration, and/or engineering ‎demand parameters (e.g. maximum story drift ratio (max SDR)) to estimate the structure's ‎damage state. In this article, a new approach is developed to map the fragility curves in adjacent ‎MRFs including effects of pounding through improved wavelet-based refined damage-sensitive ‎feature (WB-rDSF) which considers contributions of the upper modes. Morlet and complex ‎Morlet (cmorfb-fc) wavelets, which is known as extremely precise rDSF, were extended to map ‎the fragility curves. The correlation coefficient between rDSF and max SDR is evaluated as a ‎criterion to determine the efficiency of wavelets-based damage index (WB-DI). The steel MRFs ‎with six and nine stories are selected to implement the proposed approach concerning adjacent ‎MRFs prone to structural pounding during earthquakes. Acceleration responses recorded at the ‎roof of both colliding and non-colliding MRFs were determined using incremental dynamic ‎analysis (IDA) including different seismic ground motion records to formulate the damage index. ‎Moreover, the first mode structural period, used in assembling the WB-rDSF, is estimated via ‎auto-regressive moving-average with exogenous input method along with a stabilization diagram. ‎The results show that the fragility curves, derived from cmorfb-fc WB-rDSF for both colliding ‎and non-colliding MRFs due to higher correlation coefficient, have lower damage probabilities ‎and are more efficient than the estimated fragility curves based on Morlet WB-rDSF which ‎consider only the structural period of the first mode. Furthermore, due to the pounding ‎phenomenon, the lower MRF experiences more damages with a larger probability.‎

  • Development of novel (BiO)2OHCl/BiOBr enriched with boron doped-carbon nanowalls for photocatalytic cytostatic drug degradation: Assessing photocatalytic process utilization in environmental condition
    • Patrycja Wilczewska
    • Aleksandra Bielicka-giełdoń
    • Jacek Ryl
    • Michał Sobaszek
    • Mirosław Sawczak
    • Robert Bogdanowicz
    • Karol Szczodrowski
    • Anna Malankowska
    • Fei Qi
    • Ewa Siedlecka
    2022 APPLIED SURFACE SCIENCE

    In this work, a series of novel (BiO)2OHCl/BiOBr-x%B:DGNW (x = 0%, 1%, 1.5%, 2%) composites with different content of boron-doped diamond/graphene nanowalls (B:DGNW) were fabricated by simple solvothermal synthesis. A boron-doped diamond/graphene nanowalls (B:DGNW) were prepared by CVD method. A series of analyses: XRD, XPS, SEM, and TEM showed that the photocatalyst (BiO)2OHCl/BiOBr-x%B:DGNW with a “flower-like” morphology was successfully synthesized. The photocatalytic activity of the obtained composites in the degradation of 5-fluorouracil (5-FU) in various water matrices (deionized water, sea, and surface water) under the influence of artificial solar radiation was assessed. The results showed that all the prepared (BiO)2OHCl/BiOBr-x%B:DGNW composites were characterized by excellent photocatalytic activity. The calculated pseudo-first rate constant for 5-FU degradation increased with the elevation of amount of B:DGNW up to 1.5% in (BiO)2OHCl/BiOBr, and it dropped down to value obtained for non-riched material by B:DGNW, when of 2% B:DGNW was introduced to composite. The results showed that B:DGNW play a key role in the separation of charge carriers h+/e- enhancing degradation rate of 5-FU. The photoactivity of (BiO)2OHCl/BiOBr-1.5%B:DGNW composite to 5-FU removal was also satisfied in natural water, although its structure has changed in seawater.

  • Development of Safirinium dyes for new applications: fluorescent staining of bacteria, human kidney cells, and the horny layer of the epidermis
    • Joanna Fedorowicz
    • Dagmara Bazar
    • Wioletta Brankiewicz
    • Hanna Kapica
    • Krzesimir Ciura
    • Beata Zalewska-Piątek
    • Rafał Piątek
    • Krzysztof Cal
    • Krystyna Mojsiewicz-pieńkowska
    • Jarosław Sączewski
    2022 Full text Scientific Reports

    Low-molecular synthetic fluorophores are convenient tools in bioimaging applications. Several derivatives of Safirinium dyes as well as their reactive N-hydroxysuccinimide (NHS) esters bearing diverse substituents were synthesized and evaluated experimentally in terms of their lipophilicity by means of reverse-phase and immobilized artificial membrane high-performance liquid chromatography. Subsequently, the selected compounds were employed as novel cellular imaging agents for staining Gram-positive and Gram-negative bacteria, human kidney cell line, as well as human skin tissue. The analyzed dyes allowed for visualization of cellular structures such as mitochondria, endoplasmic reticulum, and cellular nuclei. They proved to be useful in fluorescent staining of stratum corneum, especially in the aspect of xenobiotic exposure and its penetration into the skin. The best results were obtained with the use of moderately lipophilic NHS esters of Safirinium Q. The development of Safirinium dyes is a promising alternative for commercially available dyes since the reported molecules have low molecular masses and exhibit efficient staining and remarkable water solubility. Moreover, they are relatively simple and low-cost in synthesis.

  • Development of SPME fiber coatings with tunable porosity for physical confinement of ionic liquids as an extraction media
    • Karolina Delińska
    • Grzegorz Machowski
    • Adam Kloskowski
    2022 MICROCHEMICAL JOURNAL

    Extending the use of ionic liquids in sample preparation techniques remains a challenge. This paper presents procedures enabling the easy application of ionic liquids to the SPME technique. For this purpose, two approaches for producing a porous silica coating on a metal rod were investigated. Two silica precursor and porogen systems were used in the research: K2SiO3 + Formamide and Tetramethyl-orthosilicate + Polyethylene oxide. The procedure was optimized concerning its operational parameters: the possibility of immobilization of a possibly large volume of ionic liquid and mechanical strength and thermal resistance. In the course of the research, it was shown that the optimal parameters are ensured by using K2SiO3 with Formamide. The obtained material had an average pore diameter equal to 0.326 μm with a surface area of the pores similar to 6.33 m2/g. The size of the pores allows for the quantitative introduction of the ionic liquid and its immobilization to the extent of enabling the extraction of VOC and their subsequent thermal desorption. Finally, the conducted experiments showed that the dominant mechanism of retaining analytes in the IL-silica hybrid material is their dissolution in the ionic liquid, while adsorption on the silica surface plays a lesser role.

  • Development of Sulfamoylated 4‑(1-Phenyl‑1H‑1,2,3-triazol-4-yl)phenol Derivatives as Potent Steroid Sulfatase Inhibitors for Efficient Treatment of Breast Cancer
    • Karol Biernacki
    • Olga Ciupak
    • Mateusz Daśko
    • Janusz Rachon
    • Witold Kozak
    • Janusz Rak
    • Konrad Kubiński
    • Maciej Masłyk
    • Aleksandra Martyna
    • Magdalena Śliwka-Kaszyńska
    • Joanna Wietrzyk
    • Marta Świtalska
    • Alessio Nocentini
    • Claudiu T. Supuran
    • Sebastian Demkowicz
    2022 Full text JOURNAL OF MEDICINAL CHEMISTRY

    We present here the advances achieved in the development of new sulfamoylated 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives as potent steroid sulfatase (STS) inhibitors for the treatment of breast cancer. Prompted by promising biological results and in silico analysis, the initial series of similar compounds were extended, appending a variety of m-substituents at the outer phenyl ring. The inhibition profiles of the newly synthesized compounds were evaluated using a radioisotope enzymatic assay and, together with the preceding reported derivatives, using a radioisotope assay in MCF-7 cells. The most active compound, 5l, demonstrated an extraordinary STS inhibitory potency in MCF-7 cells with an IC50 value improved 5-fold compared to that of the reference Irosustat (0.21 vs 1.06 nM). The five most potent compounds were assessed in vivo in a 67NR mouse mammary gland cancer model, with 4b measured to induce up to 51% tumor growth inhibition at 50 mg/kg with no evidence of side effects and toxicity.

  • Development of Technical Creativity Featuring Modified TRIZ-AM Inventive Principle to Support Design for Additive Manufacturing
    • Siti Nur Humaira Mazlan
    • Aini Zuhra Abdul Kadir
    • Mariusz Deja
    • Dawid Zieliński
    • Mohd Rizal Alkahari
    2022 Full text JOURNAL OF MECHANICAL DESIGN

    he design for additive manufacturing (DFAM) processing was introduced to fully utilise the design freedom provided by additive manufacturing (AM). Consequently, appropriate design methodologies have become essential for this technology. Recently, many studies have identified the importance of DFAM method utilisation to produce AM parts, and TRIZ is a strategy used to formalise design methodologies. TRIZ is a problem-solving tool developed to assist designers to find innovative and creative solutions. However, the pathway for synergising TRIZ and DFAM is not clearly explained with respect to AM capabilities and complexities. This is mainly because most methods continue to involve use of the classical TRIZ principle, which was developed early in 1946, 40 years before AM technologies were introduced in the mid-1980s. Therefore, to tackle this issue, this study aims to enhance the 40 principles of classical TRIZ to accommodate AM design principles. A modified TRIZ-AM principle has been developed to define the pathway to AM solutions. TRIZ-AM cards are tools that assist designers to select inventive principles (IPs) in the early phases of product design and development. The case study illustrates that even inexperienced AM users can creatively design innovative AM parts.

  • Diagnostyka cienkościennych żelbetowych sklepień kolebkowych w budynku zabytkowym
    • Tomasz Majewski
    • Maciej Niedostatkiewicz
    2022 Full text Przegląd Budowlany

    Artykuł stanowi studium przypadku oceny stanu technicznego cienkościennych żelbetowych sklepień kolebkowych stanowiących przekrycie Hali Głównej Dworca Głównego PKP w Gdańsku. W artykule szczegółowo opisano metodologie prac diagnostycznych oraz przedstawiono zaproponowany sposób naprawy sklepień

  • Diagnostyka i naprawy dylatacji konstrukcyjnych w płytach posadzkowych
    • Sylwia Świątek-Żołyńska
    • Maciej Niedostatkiewicz
    • Sebastian Kasprzak
    2022 Full text Przegląd Budowlany

    Artykuł obejmuje problematykę napraw dylatacji konstrukcyjnych w płytach posadzkowych wykonanych na gruncie wraz z omówieniem sposobów naprawy

  • Diagnostyka i wyjaśnienie aktualnego stanu 40-letniego wiaduktu kolejowego
    • Jakub Zembrzuski
    • Bartosz Sobczyk
    • Mikołaj Miśkiewicz
    2022 Full text

    Praca zawiera krótką ocenę stanu technicznego, opis przeprowadzonych badań nieniszczących in-situ oraz wykonanych modeli MES, służących do przeprowadzenia analiz na poziomie globalnym jak i lokalnym. Przedstawiono i omówiono wyniki analiz numerycznych, wykorzystanych do oceny stanu konstrukcji i mających na celu rozwiązanie sformułowanych problemów badawczych. Wykonane obliczenia na poziomie globalnym z uszczegółowieniem w obrębie fragmentu skrajnego przęsła dostarczyły wyjaśnienia przyczyny nie wystąpienia awarii, która miałaby być spowodowana brakami w spoinie czołowej blach płyty ortotropowej. Wykazano, że styk pozostaje w równowadze i nie ulega rozwarciu, ponieważ występują w nim jedynie naprężenia ściskające i blachy „zakleszczają” się wzajemnie. Znaleziono również przyczynę powstania gwałtownego przyrostu wartości na wykresie naprężeń w przekroju poprzecznicy. W wyniku analizy przeprowadzonej na modelu lokalnym, wykonanym w programie ABAQUS wykazano, że przyczyną wystąpienia „skoku” wartości był fakt lokalizacji punktów pomiarowych odkształceń (naprężeń) w strefie silnej koncentracji naprężeń. Co istotne, podczas analizy zagadnienia i wprowadzanych do modeli numerycznych modyfikacji, zaaplikowano z sukcesem uproszczony sposób modelowania połączenia nitowanego, wykorzystujący częściowo techniki modelowania numerycznego stosowane zwykle w analizach na poziomie globalnym, a pozwalający uzyskiwać zadowalające wyniki w analizach lokalnych. Uzyskane wyniki mają duże znaczenie na polu możliwości oceny pracy konstrukcji mostowych z płytą ortotropową. Etapowe dochodzenie do rozwiązania problemu od modelu numerycznego globalnego do szczegółowego, co więcej z wykorzystaniem wyników badań in-situ, mogą stanowić wytyczne do oceny stanu analogicznych do badanego obiektów mostowych.

  • Diagnostyka uszkodzeń żelbetowej, monolitycznej ściany w realizowanym budynku wielorodzinnym
    • Maciej Niedostatkiewicz
    • Tomasz Majewski
    2022 Full text Materiały Budowlane

    W artykule przedstawiono przypadek uszkodzeń żelbetowej, monolitycznej ściany, do którego doszło podczas demontażu systemowych szalunków prefabrykowanych. W miejscu uderzenia beton uległ wykruszenia, poniżej przy górnej części ściana rozwarstwiła się. Wykonane badania diagnostycze za pomocą metody ultradźwiękowej umożliwiły określenie zakresu uszkodzenia i opracowani optymalnej metody naprawy

  • Diamond investments – Is the market free from multiple price bubbles?
    • Marcin Potrykus
    2022 Full text International Review of Financial Analysis

    The following study aims to investigate whether multiple price bubbles, in which the quoted market price of diamonds significantly deviates from their fundamental value, exist in the diamond market. It was conducted using ADF, SADF and GSADF tests, with the latter found to be an optimal form of evaluating the analysed issue. The presented results support the conclusion that the diamond market is not free from periods defined as price bubbles. The study revealed price bubbles related to the leading, albeit declining in recent years, position of De Beers within the market and its activities, the financial crisis of 2008, the subsequent European debt crisis, and the crisis caused by the aggression of the Russian Federation against Ukraine in 2022. However, the identified periods of speculative bubbles in the diamond market are short and tend to affect the rough diamond segment earlier than the broader diamond market.

  • Diamond protection for reusable ZnO coated fiber-optic measurement head in optoelectrochemical investigation of bisphenol A
    • Małgorzata Szczerska
    • Monika Kosowska
    • Paulina Listewnik
    • Michał Rycewicz
    • Mikhael Bechelany
    • Yafit Fleger
    • Dror Fixler
    • Paweł Jakóbczyk
    2022 Full text MEASUREMENT

    Due to the global problem with plastic contaminating the environment, with bisphenol A (BPA) being one of the highest demand, effective monitoring and purification of the pollutants are required. The electrochemical methods constitute a good solution but, due to polymerization of electrochemical oxidation bisphenol A products and their adsorption to the surfaces, measurement head elements are clogged by the formed film. In this research, we propose a nanocrystalline diamond sheet protection for securing elements in direct contact with bisphenol A during electrochemical processes. The solution was presented on the example of a zinc oxide (ZnO) coating deposited on a fiber-optic end-face by Atomic Layer Deposition. Series of optical and electrochemical measurements were performed in a dedicated hybrid setup. The results show that ZnO can be modified during the electrochemistry leading to the drastic change of its properties. Such degradation did not show in case of nanocrystalline diamond sheet-protected sample proving the solution’s effectiveness, giving a possibility of re-using the measurement element and prolonging its lifespan.

  • Diamond Structures for Tuning of the Finesse Coefficient of Photonic Devices
    • Monika Kosowska
    • Awadesh Mallik
    • Michał Rycewicz
    • Ken Haenen
    • Małgorzata Szczerska
    2022 Full text Materials

    Finesse coefficient is one of the most important parameters describing the properties of a resonant cavity. In this research, a mathematical investigation of the application of diamond structures in a fiber-optic Fabry–Perot measurement head to assess their impact on the finesse coefficient is proposed. We present modeled transmission functions of cavities utilizing a nitrogen-doped diamond, a boron-doped diamond, nanocrystalline diamond sheet and a silver mirror. The diamond structures were deposited using a microwave plasma-assisted chemical vapor deposition system. A SEM investigation of surface morphology was conducted. The modeling took into consideration the fiber-optic Fabry–Perot setup working in a reflective mode, with an external cavity and a light source of 1550 nm. A comparison of the mathematical investigation and experimental results is presented.

  • Diamondized carbon nanoarchitectures as electrocatalytic material for sulfate-based oxidizing species electrogeneration
    • Karla Caroline de Freitas Araújo
    • Elisama Vieira dos Santos
    • Mattia Pierpaoli
    • Mateusz Ficek
    • José Eudes L. Santos
    • Carlos A. Martínez-Huitle
    • Robert Bogdanowicz
    2022 Full text ELECTROCHIMICA ACTA

    The introduction of nanotechnology seems to be an imperative factor to intensify the synergic effects of electrocatalytic materials to produce strong oxidant species or to increase the active sites on their surfaces as well as to enhance the conversion yield in a fuel cell, high-added value products, electrolytic treatment for environmental protection or the detection limit in electroanalysis. Recently, a new type of 3D-diamond electrodes was developed with boron-doped carbon nanowalls (B:CNW), which was manufactured using the microwave plasma-assisted chemical vapor deposition (CVD) process, improving the charge transfer and enhancing the electrochemical performance. The applicability of a BDD/boron-doped carbon nanowalls (BDD/B:CNW) anodes to degrade organic pollutants has been already investigated; however, no attempts at the electrosynthesis of oxidizing species using these diamond-carbon nanostructures have been reported yet. Therefore, the electrosynthesis of sulfate-based oxidizing species was studied here to answer relevant questions from both fundamental and practical point-of-view. The results demonstrated that persulfate was efficiently produced at the BBD electrode, while that the ion-radical sulfate could be the most important oxidant at BDD/B:CNW anode when compared to other electrocatalytic materials, including BDD surfaces. Persulfate concentrations ranged from 3 to 6 µM, depending on the applied current density (2.5, 5.0, and 15 mA cm−2), at diamond electrodes. A dye-model pollutant - methyl orange (MO) was degraded below the limit of detection within 45 min using BDD/B:CNW when in-situ sulfate-based oxidizing species were electrogenerated. These kinds of 3D-diamond-carbon nanostructures are thus promising as novel electrocatalyst for various catalytic applications in the environmental and energy fields.

  • Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement
    • Magdalena Łępicka
    • Magdalena Rodziewicz
    • Michał Kawalec
    • Klaudia Nowicka
    • Yurii Tsybrii
    • Jan Krzysztof Kurzydłowski
    2022 Full text Journal of the Mechanical Behavior of Biomedical Materials

    The effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer cement (GIC). Three sample series, differing in DE content (0, 2.5 and 5 wt%), were prepared using a commercial GIC as a matrix (3M Ketac Molar Easymix). The resultant surface microhardness and roughness, wear performance, and compressive strength of the samples were measured after the samples had been stored in deionized water at 37°C for a fixed time. Moreover, the film thickness was tested for the freshly mixed samples. The numerical data was subjected to statistical analysis, in order to test the null hypotheses of the equality of the measured properties between the reference and the DE-modified samples. According to the results, diatomaceous earth particles are uniformly distributed in the GIC matrix, and the cavities of frustules tend to be filled with the GIC. This translates into the observed performance of the DE-loaded GIC. Compared with the reference material (0 wt% DE), the surface microhardness (2.5 wt% DE, p = 0.014; 5 wt% DE, p = 0.005) and roughness (e.g. Ra; 2.5 wt% DE, p = 0.003; 5 wt% DE, p < 0.001) are increased. No effect on the wear performance (p = 0.530 and 0.256, respectively) or compressive strength (p = 0.514) was noticed in the case of DE partially substituting the glass phase. Based on the study results, it is evidenced that diatom frustules are a suitable filler for application in conventional glass-ionomer cements as the glass-substituting drug-loaded carrier. Notably, however, the surface finish method of the DE-filled materials needs development.

  • Dietary behaviour and physical activity policies in Europe: learnings from the Policy Evaluation Network (PEN)
    • Wolfgang Ahrens
    • Hermann Brenner
    • Marion Flechtner-Mors
    • Janas M Harrington
    • Antje Hebestreit
    • Carlijn B.M. Kamphuis
    • Liam Kelly
    • Michael Laxy
    • Aleksandra Luszczynska
    • Mario Mazzocchi
    • Celine Murrin
    • Maartje Poelman
    • Ingrid Hm Steenhuis
    • Gun Roos
    • Jürgen Meichsner
    • Frank van Lenthe
    • Hajo Zeeb
    • Joanna Żukowska
    • Jeroen Lakerveld
    • Catherine B Woods
    2022 Full text EUROPEAN JOURNAL OF PUBLIC HEALTH

    The European Policy Evaluation Network (PEN), initiated in autumn 2018, aimed at advancing the evidence base for public policies impacting dietary behaviour, physical activity and sedentary behaviours in Europe. This is needed because non-communicable diseases—the leading cause of global mortality—are substantially caused by physical inactivity and unhealthy dietary behaviours, which in turn are driven by upstream factors that have not yet been addressed effectively by prevention approaches. Thus, successful policy interventions are required that target entire populations and tackle the ‘causes of the causes’. To advance our knowledge on the effective implementation of policies and their impact in terms of improving health behaviours, PEN focused on five research tasks: (i) Adaptation and implementation of a Food Environment Policy Index (Food-EPI) and development of a Physical Activity Environment Policy Index (PA-EPI); (ii) Mapping of health-related indicators needed for policy evaluation and facilitating a harmonized pan-European approach for surveillance to assess the impact of policy interventions; (iii) Refining quantitative methods to evaluate the impact of public policies; (iv) Identifying key barriers and facilitators of implementation of policies; and (v) Advance understanding the equity impact of the development, implementation and evaluation of policies aimed at promoting physical activity and a healthy diet. Finally, and in order to provide concrete evidence for policymaking, existing exemplary policies, namely sugar-sweetened beverages taxation, active transport policies and school policies on nutrition and physical activity were assessed in consideration of these five tasks. At the end of the PEN project’s formal runtime, considerable advancements have been made. Here, we present an overview of the most important learnings and outputs.

  • Digital Gaps and Economic Inequalities in MENA Countries: An Empirical Investigation
    • Ewa Lechman
    2022

    This research contributes to the present state of the art by examining changes in cross-country inequalities in digital technologies deployment and economic performance. Our empirical target builds on the hypothesis that rapid global diffusion of digital technologies unequivocally leads to gradual eradication of cross-country digital gaps and cross-country inequalities in terms of deployment of ICT; the technology convergence occurs. Bearing in mind the fact that digital technologies’ growing access and use boost country’s economic performance, we confront changes in cross-country inequalities in terms of economic development. We hypothesize that gradual elimination of digital gaps shall be followed by diminishing gaps in economic wealth. Our country sample covers Middle East and North Africa (MENA) countries, and the time span of analysis covers the period 1990–2020. To test changes in digital development inequalities, we use 4 core ICT indicators: mobile cellular telephony, fixed broadband and mobile broadband networks, and Internet users, while regarding economic performance, we consider gross per capita income and Human Development Index. Our major findings support the hypothesis on dropping cross-country economic inequalities, which are accompanied by fast digital gaps being eradicated.

  • DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
    • Jan Zubair Ahmed
    • Paweł Śliwiński
    • Krzysztof Kędzia
    2022

    Hydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital hydraulics because it is inexpensive, it saves energy, it is not sensitive to contamination, and it has low leakage. In this paper, a digital hydraulic circuit is suggested that uses a fast switching on/off valve instead of servo valves to control the position of a hydraulic actuator. Using a proper PWM duty cycle, the flow that passes through the fast-switching valve is controlled in this way. When the control valve is off, excess pump flow flows straight to the tank instead of going through the relief valve. Therefore, the waste of energy caused by the relief valve is greatly reduced. A robust sliding mode controller (SMC) is used to ensure position tracking even when there are uncertainties.

  • Digital transformation and economic growth - DESI improvement and implementation
    • Magdalena Olczyk
    • Marta Kuc-Czarnecka
    2022 Full text Technological and Economic Development of Economy

    The paper aims to improve the methodology of the Digital Economic and Society Index (DESI), the European Commission’s newest index to assess the development of the digital economy. In particular, we investigate whether methodological changes to the structure of DESI improve its ability to capture the digital transformation of EU economies. Using the sensitivity- based analysis, we check whether the selection of weights of individual elements included in the DESI is optimal or should be improved. We also verify the importance of DESI in explaining changes in GDP per capita in EU econo- mies. In the literature, we find that digital transformation has enabled the creation of new business models and maximized efficiency in traditional firms. Using DESI, we empirically test whether the gap between rich and poor countries in European Union can be closed or eliminated through rapid and intensive digital transformation. Our results show that the DESI – when modified by eliminating the pillars on internet services and digital public services – has the same explanatory power. Connectivity is the dimension with the largest impact on digital transformation in EU countries. We also find that DESI is a signifi- cant regressor to explain changes in GDP per capita in EU countries

  • Digitalizacja nie śpi! Czy w Bibliotece Politechniki Gdańskiej sprostamy wyzwaniom stawianym przez cyfrową humanistykę?
    • Kamila Kokot-Kanikuła
    • Anna Sobolewska
    2022 Full text Biuletyn EBIB

    Celem artykułu jest przedstawienie działań Biblioteki Politechniki Gdańskiej w zakresie digitalizacji oraz udostępniania zasobów kultury i nauki na platformie Pomorskiej Biblioteki Cyfrowej. Podejmowane zadania zostały zestawione z ogłoszonymi w 2020 r. postulatami międzynarodowej organizacji DARIAH zajmującej się dostarczaniem społecznościom naukowym metod cyfrowych do tworzenia, łączenia i dzielenia się wiedzą.

  • Digitalization of High Speed Craft Design and Operation Challenges and Opportunities
    • Abbas Dashtimanesh,
    • Mohammad Ghaemi
    • Youjiang Wang
    • Artur Karczewski
    • Rasul Niazmand Bilandi
    • Spyros Hirdaris
    2022 Full text Procedia Computer Science

    In recent years, global demands for safe and sustainable ships led to dramatic changes in the maritime industry. Digitalization is expected to play an important part in the future. This is supported by analysis of the autonomous ships market which shows that digitalization of large ship types such as tankers and container ships is well on track. Although to date designs of autonomous High-Speed Craft (HSC) have been developed, there are only a few studies on the impact of digitalization on design and operations. This is because of the challenging operational profile of these assets across a spread of waterborne activities namely fishing, leisure, patrolling, and rescuing. This paper reviews the literature of relevance on the potential of digitalization of the HSC sector in the Baltic. An overview of the systems that could be partly digitalized and how technology developments may influence operations are also outlined.

  • Digitalization Process and Its Impact on Economic Growth A Panel Data Study for Developing Countries
    • Ewa Lechman
    • Helena Anacka
    2022

    This book analyses the impact of Information and Communication Technologies (ICTs) on economic development. It contains theoretical and empirical studies, including panel studies on various issues facing developing countries, such as education, corruption, economic growth, government expenditure, financial inclusion, foreign direct investment, infrastructure, economic and social welfare, and inequality. Each chapter offers a well-conceived analysis of the most recent trends in both theory and empirics and addresses numerous policy implications related to the different aspects dealt with in the volume.

  • Direct Constraint Control for EM-Based Miniaturization of Microwave Passives
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 Full text Scientific Reports

    Handling constraints imposed on physical dimensions of microwave circuits has become an important design consideration over the recent years. It is primarily fostered by the needs of emerging application areas such as 5G mobile communications, internet of things, or wearable/implantable devices. The size of conventional passive components is determined by the guided wavelength, and its reduction requires topological modifications, e.g., transmission line folding, or utilization of compact cells capitalizing on the slow-wave phenomenon. The resulting miniaturized structures are geometrically complex and typically exhibit strong cross coupling effects, which cannot be adequately accounted for by analytical or equivalent network models. Consequently, electromagnetic (EM)-driven parameter tuning is necessary, which is computationally expensive. When the primary objective is size reduction, the optimization task becomes far more challenging due to the presence of constraints related to electrical performance figures (bandwidth, power split ratio, etc.), which are all costly to evaluate. A popular solution approach is to utilize penalty functions. Therein, possible violations of constraints degrade the primary objective, thereby enforcing their satisfaction. Yet, the appropriate setup of penalty coefficients is a non-trivial problem by itself, and is often associated to extra computational expenses. In this work, we propose an explicit approach to constraint handling, which is combined with the trust-region gradient-search procedure. In our technique, the decision about the adjustment of the search radius is determined based on the reliability of rendering the feasible region boundary by linear approximation models of the constraints. Comprehensive numerical experiments conducted using three miniaturized coupler structures demonstrate superiority of the presented method over the penalty function paradigm. Apart from the efficacy, its appealing features include algorithmic simplicity, and no need for tailoring the procedure for a particular circuit to be optimized.

  • Direct-contact condensation from vapour- gas mixture in a spray ejector condenser for negative CO2 power plant
    • Dariusz Mikielewicz
    • Milad Amiri
    • Jaroslaw Mikielewicz
    2022 Full text

    Direct-contact condensation of vapour containing the inert gas on a spray of subcooled liquid exists in a number of technical applications. For example, it may be found in the nuclear industry (e.g. pressurized jet under normal operating conditions, in safety analyses) or in the chemical industry (e.g. mixing-type heat exchanger, degasser, sea water desalting). The problem is also essential to modelling and analysis of some fundamental phenomena of two phase flow, such as condensation in power engineering condenser of steam power plant as well as a new concept of negative CO2 power plant, where separation of carbon dioxide from the mixture of steam and inert gas takes place in the spray ejector condenser (SEC) followed by the centrifugal separation in the cyclone. The phenomenon of direct-condensation heat transfer is primarily characterized by the appropriate transport of heat and mass through a moving vapour-liquid interface. Furthermore, using a spray ejector condenser (SEC) with separators can be considered as an alternative method to increase the efficiency of separation process. The present survey attempts to investigate the effect of different initial velocity of mixture and droplet on their temperature as well as the effect of diameter of throat on temperature of droplet and mixture. For the ejector design, the study focuses on the ejector nozzle, pre-mixing chamber, the mixing section and the diffuser. Flow properties and ejector geometry are considered using the thermodynamic equations, conservation equations and other assumptions established based on literature. Comparisons with experimental data show a good consistency with experimental results. Results show that increasing the value of initial velocity of mixture of steam (Um0) not only results in increasing the temperature of droplet, but also leads to rise the temperature of mixture of steam at the length of throat. Moreover, the lowest value for temperature of droplet and mixture of steam is when the drop is moving in stagnant environment (() = 0).

  • Direction of Arrival Estimation Based on Received Signal Strength Using Two-Row Electronically Steerable Parasitic Array Radiator Antenna
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2022 Full text SENSORS

    In this paper, we present a novel approach to direction-of-arrival (DoA) estimation using two-row electronically steerable parasitic array radiator (ESPAR) antenna which has 12 passive elements and allows for elevation and azimuth beam switching using a simple microcontroller, relying solely on received signal strength (RSS) values measured at the antenna output port. To this end, we thoroughly investigate all 18 available 3D antenna radiation patterns of the antenna measured in an anechoic chamber with respect to radiation coverage in the horizontal and vertical direction and propose a generalization of the power-pattern cross-correlation (PPCC) algorithm involving a high number of multiple calibration planes (MCP) as well as specific combinations of radiation pattern sets. Additionally, a new way of RSS-based DoA estimation accuracy assessment, which involves thorough testing conducted along the elevation direction when RF signals impinging on the antenna arrive from arbitrary θ angles, has been reported in this paper to verify the overall algorithm’s performance. The results obtained for different signal-to-noise ratio (SNR) levels indicate that two-row ESPAR antenna can produce, even for low SNR values, accurate DoA estimation in the horizontal plane without prior knowledge about the elevation direction of the unknown RF signals by using appropriate combinations of only 12 3D antenna radiation patterns.

  • Directions of Energy Transition of Uzbekistan
    • Krystyna Gomółka
    • Piotr Kasprzak
    2022

    The aim of the paper is to present the changes in the Uzbekistan energy market over the past few years. Uzbekistan is self-sufficient in terms of energy resources, the exploitation of which will last for many years. In 2019, the government adopted the "Concept Note ensuring electricity supply in Uzbekistan in 2020-2030" strategy, which announced the modernization of gas and coal power plants and the construction of new energy facilities, mainly photovoltaic. The projected increase in energy until 2030 assumes a 25% share in the production of renewable energy sources. A novelty in the work is the analysis of energy projects implemented until September 2021 in Uzbekistan. Its results show that the planned 25% share of renewable energy sources in the overall energy balance of Uzbekistan may not be achieved because financial resources from international sources have been allocated to the modernization of the existing gas and coal-fired power plants.

  • Discovering interactions between applications with log analysis
    • Krzysztof Goczyła
    • Łukasz Korzeniowski
    2022 Full text Annals of Computer Science and Information Systems

    Application logs record the behavior of a system during its runtime and their analysis can provide useful information. In this article, we propose a method of automated log analysis to discover interactions taking place between applications in an enterprise. We believe that such an automated approach can greatly support enterprise architects in building an up-to-date view of a governed system in a modern, fast-paced development environment. Our contribution is the following: we propose a new method for log template generation called SLT (Simple Log Template), we propose a method of extracting knowledge about application interactions from logs, and we validate the proposed methods on a real system running at Nordea Bank. Additionally, we collect statistical information about application logs from the real-life system, based on which we formulate some observations that support our method.

  • Discussion of “Stress-Displacement Response of Sand–Geosynthetic Interfaces under Different Volume Change Boundary Conditions” by Aliyeh Afzali-Nejad, Ali Lashkari, and Alejandro Martinez
    • Lech Bałachowski
    • Jakub Konkol
    2022 Full text JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING

    The influence of normal stiffness of interface on the interpretation of shear box tests

  • Dispersive Delay Structures With Asymmetric Arbitrary Group-Delay Response Using Coupled-Resonator Networks With Frequency-Variant Couplings
    • Maciej Jasiński
    • Martyna Mul
    • Adam Lamęcki
    • Roberto Gomez-Garcia
    • Michał Mrozowski
    2022 Full text IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    This article reports the design of coupled-resonatorbased microwave dispersive delay structures (DDSs) with arbitrary asymmetric-type group delay response. The design process exploits a coupling matrix representation of the DDS circuit as a network of resonators with frequency-variant couplings (FVCs). The group delay response is shaped using complex transmission zeros (TZs) created by dispersive cross-couplings. We also present an optimization-based synthesis procedure for characteristic polynomials with a prescribed group delay profile. Thus, when compared with prior-art DDS approaches, the proposed DDS solutions allow a general group delay profile to be patterned while incorporating optimization-based coupling matrix design techniques for their synthesis. The design method is validated by full-wave simulations and measurements of three built proof-ofconcept prototypes of DDS devices with different shapes of group delay response in waveguide and microstrip technologies

  • Displacement Sensors Based on the Phase of the Reflection Coefficient of a Split Ring Resonator Loaded Transmission Line
    • Zahra Shaterian
    • Michał Mrozowski
    2022 IEEE SENSORS JOURNAL

    — In this paper, novel displacement sensors using a microstrip loaded with a pair of split ring resonators (SRRs) are proposed. It is shown that the phase of the reflection coefficient from the loading SRRs can be used for displacement sensing. The paper also proposes a differential version of the sensor that benefits from a higher sensitivity and reference zero, which is useful for alignment purposes. It is further shown that the concept of interferometry can be used to convert the output variable of the sensor from changes in the phase to variation in the amplitude of the reflected wave, which can be easily measured. To this end, the proposed single-ended or differential sensors are used along with a branch-line coupler. The proposed sensing mechanism is validated through EM simulation of the structures. The concept is further validated through the fabrication and measurement of a prototype