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Politechniki Gdańskiej

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  • Revitalisation Living Lab as a Format to Accelerate an Energy Transition in Polish Rural Areas: The Case Studies of Metropolitan Outskirts Gdańsk-Orunia and Lubań
    • Bartosz Pietrzykowski
    • Gabriela Rembarz
    • Adam Cenian
    2022

    The paper deals with the issue of energy transition in the revitalization process dedicated to the rural and semi-rural areas of the Pomerania Region (PR). Two distinct areas, located in sub- and ex-urban zones of the Gdańsk-Gdynia-Sopot Metropolitan Area (OMGGS), in which bottom-up community initiatives have been playing a key role in the transformation, have been focused on. The village of Lubań (Municipality of Nowa Karczma) and the Orunia agrihood suburb of Gdańsk, i.e. two case studies in a planned revitalization program, pose an opportunity for extensive refurbishment of the heat and energy supply. The research approach runs in the Living Lab format, allowing studies based on the activities implemented and planned in the hitherto neglected field of integrated quest for energy efficiency.

  • Rewaloryzacja historycznego zajazdu Adlera w Gdyni Orłowie
    • Robert Hirsch
    • Celina Łozowska
    2022

    Tekst omawia kompleksowe prace konserwatorskie przy zabytkowym zajeździe położonym w Gdyni Orłowie. Budynek powstał w XIX w. w dwóch etapach. Przeprowadzone w latach 2011-2013 prace obejmowały m.in. wzmocnienie fundamentów, wybudowanie niezależnej konstrukcji stalowej, która odciążyła szkielet z belek drewnianych, termomodernizację oraz prace restauratorskie przy elewacjach.

  • Rheology of Variable Viscosity‐Based Mixed Convective Inclined Magnetized Cross Nanofluid with Varying Thermal Conductivity
    • Adil Darvesh
    • Tanveer Sajid
    • Wasim Jamshed
    • Assad Ayub
    • Zahir Shah
    • Mohamed Eid
    • Syed M. Hussain
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    2022 Pełny tekst Applied Sciences-Basel

    Cross nanofluid possesses an extraordinary quality among the various fluidic models to explore the key characteristics of flowing fluid during very low and very high shear rates and its viscosity models depend upon shear rate. The current study establishes the numerical treatment regarding variable viscosity‐based mixed convective inclined magnetized Cross nanofluid with var‐ ying thermal conductivities over the moving permeable surface. Along with variable thermal con‐ ductivities, we considered thermal radiation, thermophoresis, and the Brownian motion effect. An inclined magnetic field was launched for velocity scrutiny and the heat transfer fact was numeri‐ cally seen by mixed convective conditions. Similarity variables were actioned on generated PDEs of the physical model and conversion was performed into ODEs. Numerical results showed that the frictional force and Nusselt quantity considerably influence the skinning heat transfer processes over the geometry of a moving permeable surface. Furthermore, less velocity was noticed for the greater suction parameter and the Brownian motion parameter corresponds to lower mass transport.

  • Ribes nigrum L. Extract-Mediated Green Synthesis and Antibacterial Action Mechanisms of Silver Nanoparticles
    • Zaruhi Hovhannisyan
    • Marina Timotina
    • Jemma Manoyan
    • Lilit Gabrielyan
    • Margarit Petrosyan
    • Barbara Kusznierewicz
    • Agnieszka Bartoszek-Pączkowska
    • Claus Jacob
    • Mikayel Ginovyan
    • Karen Trchounian
    • Naira Sahakyan
    • Muhammad Jawad Nasim
    2022 Pełny tekst Antibiotics-Basel

    Silver nanoparticles (Ag NPs) represent one of the most widely employed metal-based engineered nanomaterials with a broad range of applications in different areas of science. Plant extracts (PEs) serve as green reducing and coating agents and can be exploited for the generation of Ag NPs. In this study, the phytochemical composition of ethanolic extract of black currant (Ribes nigrum) leaves was determined. The main components of extract include quercetin rutinoside, quercetin hexoside, quercetin glucuronide, quercetin malonylglucoside and quercitrin. The extract was subsequently employed for the green synthesis of Ag NPs. Consequently, R. nigrum leaf extract and Ag NPs were evaluated for potential antibacterial activities against Gram-negative bacteria (Escherichia coli ATCC 25922 and kanamycin-resistant E. coli pARG-25 strains). Intriguingly, the plant extract did not show any antibacterial effect, whilst Ag NPs demonstrated significant activity against tested bacteria. Biogenic Ag NPs affect the ATPase activity and energy-dependent H+-fluxes in both strains of E. coli, even in the presence of N,N’-dicyclohexylcarbodiimide (DCCD). Thus, the antibacterial activity of the investigated Ag NPs can be explained by their impact on the membrane-associated properties of bacteria.

  • Robust and Efficient Machine Learning Algorithms for Visual Recognition
    • Sebastian Cygert
    2022 Pełny tekst

    In visual recognition, the task is to identify and localize all objects of interest in the input image. With the ubiquitous presence of visual data in modern days, the role of object recognition algorithms is becoming more significant than ever and ranges from autonomous driving to computer-aided diagnosis in medicine. Current models for visual recognition are dominated by models based on Convolutional Neural Networks (CNNs), which achieve impressive performance on many benchmarks. However, when deployed to the real world, the performance of these CNN models can drop drastically, lacking the desired robustness property. This is because of the so-called distributional shift, where the test-time data differ from data observed during training, and it poses one of the most important challenges in modern machine learning. At the same time, modern CNN-based models may be too expensive or too slow for general deployment. As such, the goal of this thesis is to develop robust and efficient models for visual object recognition. In the experimental section, the focus is on autonomous driving because of the datasets' availability, and also because the aforementioned problems are essential for autonomous driving. The next goal was to understand the impact of model compression methods is on model accuracy. Model compression works by removing some neurons or filters during training, which improves the inference time, without hurting overall accuracy. It was hypothesized that one of the reasons for this is data imbalance, a~compressed model (with smaller capacity) will firstly remove neurons responsible for recognition of less-common data. The experimental section found that using data balancing methods helped to improve the accuracy of some classes.

  • Robust Object Detection with Multi-input Multi-output Faster R-CNN
    • Sebastian Cygert
    • Andrzej Czyżewski
    2022

    Recent years have seen impressive progress in visual recognition on many benchmarks, however, generalization to the out-of-distribution setting remains a significant challenge. A state-of-the-art method for robust visual recognition is model ensembling. However, recently it was shown that similarly competitive results could be achieved with a much smaller cost, by using multi-input multi-output architecture (MIMO). In this work, a generalization of the MIMO approach is applied to the task of object detection using the general-purpose Faster R-CNN model. It was shown that using the MIMO framework allows building strong feature representation and obtains very competitive accuracy when using just two input/output pairs. Furthermore, it adds just 0.5% additional model parameters and increases the inference time by 15.9% when compared to the standard Faster R-CNN. It also works comparably to or outperforms the Deep Ensemble approach in terms of model accuracy, robustness to out-of-distribution setting, and uncertainty calibration when the same number of predictions is used. This work opens up avenues for applying the MIMO approach in other high-level tasks such as semantic segmentation and depth estimation.

  • Robust Object Detection with Multi-input Multi-output Faster R-CNN
    • Sebastian Cygert
    • Andrzej Czyżewski
    2022 Pełny tekst

    Recent years have seen impressive progress in visual recognition on many benchmarks, however, generalization to the out-of-distribution setting remains a significant challenge. A state-of-the-art method for robust visual recognition is model ensembling. However, recently it was shown that similarly competitive results could be achieved with a much smaller cost, by using multi-input multi-output architecture (MIMO). In this work, a generalization of the MIMO approach is applied to the task of object detection using the general-purpose Faster R-CNN model. It was shown that using the MIMO framework allows building strong feature representation and obtains very competitive accuracy when using just two input/output pairs. Furthermore, it adds just 0.5% additional model parameters and increases the inference time by 15.9% when compared to the standard Faster R-CNN. It also works comparably to or outperforms the Deep Ensemble approach in terms of model accuracy, robustness to out-of-distribution setting, and uncertainty calibration when the same number of predictions is used. This work opens up avenues for applying the MIMO approach in other high-level tasks such as semantic segmentation and depth estimation.

  • Role of the Synergistic Interactions of Environmental Pollutants in the Development of Cancer
    • Francisco Alejandro Lagunas‐Rangel
    • Jenni Viivi Linnea‐Niemi
    • Błażej Kudłak
    • Michael Williams
    • Jörgen Jönsson
    • Helgi B. Schiöth
    2022 Pełny tekst GeoHealth

    There is a growing awareness that the large number of environmental pollutants we are exposed to on a daily basis are causing major health problems. Compared to traditional studies that focus on individual pollutants, there are relatively few studies on how pollutants mixtures interact. Several studies have reported a relationship between environmental pollutants and the development of cancer, even when pollutant levels are below toxicity reference values. The possibility of synergistic interactions between different pollutants could explain how even low concentrations can cause major health problems. These intricate that molecular interactions can occur through a wide variety of mechanisms, and our understanding of the physiological effects of mixtures is still limited. The purpose of this paper is to discuss recent reports that address possible synergistic interactions between different types of environmental pollutants that could promote cancer development. Our literature studies suggest that key biological pathways are frequently implicated in such processes.

  • Rotational molding of polylactide (PLA) composites filled with copper slag as a waste filler from metallurgical industry
    • Mateusz Barczewski
    • Aleksander Hejna
    • Joanna Aniśko
    • Jacek Andrzejewski
    • Adam Piasecki
    • Olga Mysiukiewicz
    • Małgorzata Bąk
    • Bartosz Gapiński
    • Zaida Ortega
    2022 Pełny tekst POLYMER TESTING

    The research work carried out so far indicates the ever wider possibilities and demand for shaping composite products in the rotational molding technology. This trend was the main reason to use waste-based filler from the metallurgical process as a filler for manufacturing polylactide (PLA)-based remolded composites. Copper slag (CS) was introduced in the single-step processing method to PLA matrix at 5, 10, 20, and 35 wt%. The rotomolded composites with different filler content were subjected to in-depth structural analysis discussed in relationship with mechanical and thermomechanical properties changes. Evaluation of the composite structures by scanning electron microscopy (SEM) and 3D computer tomography (3D CT) analyses showed that incorporating up to 10 wt% of the filler did not cause adverse changes in the filler dispersion in the product volume was homogeneous. Lack of unfavorable structural changes in composites with concentrations of up to 20 wt% was related to the rheological properties of the composition. Except for series with the highest filler content (35 wt%), the produced composites were characterized by increased stiffness and hardness than rotomolded parts made from pure PLA. Despite the deterioration of the tensile strength of composite materials using higher filler concentrations, the mechanical performance of 5 and 10 wt% showed an acceptable level while increasing the stiffness by about 15% compared to neat PLA. Moreover, it was shown that the interfacial adhesion between PLA and CS, despite the lack of surface modification of the filler waste, was advantageous.

  • Rozwój diagnostyki termicznej metodami detekcji podczerwieni i wdrożenie procedur nieinwazyjnej, ilościowej diagnostyki podczerwieni w monitoringu zabiegów kardiochirurgicznych, leczeniu ran oparzeniowych i pooperacyjnych
    • Mariusz Kaczmarek
    • Antoni Nowakowski
    2022 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Celem naukowym prowadzonych prac był rozwój algorytmów i procedur diagnostyki termicznej drogą bezkontaktowych pomiarów termicznych w podczerwieni, w celu wdrożenia ich do obiektywnej, ilościowej, nieuraźnej i bezstresowej oceny stanu tkanki w wybranych aplikacjach diagnostyki medycznej. Opracowane metody zweryfikowano w następujących aplikacjach medycznych: w ocenie głębokości oparzeń, w ocenie stanu mięśnia sercowego w zabiegach pomostowania tętnic wieńcowych metodami klasycznymi, jak również małoinwazyjnymi oraz w innych zabiegach na otwartym sercu; w ocenie stanu i postępów gojenia się ran pooperacyjnych, w tym po interwencjach kardiochirurgicznych. Prace badawcze wykazały, że metody termiczne (aktywna termografia dynamiczna) mają doskonałe właściwości różnicowania tkanek, porównywalne z jakością referencyjnej metody, jaką są badania histopatologiczne. Metody termiczne są całkowicie nieinwazyjne oraz umożliwiają szybki, obiektywny i rozległy przestrzennie pomiar oraz klasyfikację rany, a także właściwą ilościową dokumentację przebiegu leczenia. Takie badanie można wielokrotnie powtarzać bez szkody dla pacjenta oraz personelu. Metodę zweryfikowano klinicznie w Gdańskim Uniwersytecie Medycznym, w klinikach: Chirurgii Plastycznej, Chirurgii Onkologicznej, Kardiochirurgii i Chirurgii Naczyniowej oraz w Zachodniopomorskim Centrum Leczenia Ciężkich Oparzeń i Chirurgii Plastycznej w Gryficach. Rezultatem prac jest opracowanie, optymalizacja i implementacja prototypowej aparatury i oprogramowania nadającego się do wdrożenia produkcyjnego i aplikacji w warunkach klinicznych.

  • Rozwój podejścia proekologicznego w projektowaniu urbanistycznym i architektonicznym.
    • Katarzyna Zielonko-Jung
    2022

    Rozdział dotyczy rozwoju tendencji w podejściu projektowania z uwzględnieniem kryteriów ekologicznych. Zapoczątkowane w połowie XX wieku wciąż się rozwija, wzrasta liczba kryteriów oraz przesuwają się towarzyszące im akcenty. W artykule wskazano kryteria obecnie uważane za kluczowe. Odniesiono je następnie do elementów projektowych zawartych w prezentowanym w monogrrafii zestawie koncepcji studencki dotyczących nowej dzielnicy Rumi.

  • S09-4 The development of the Physical Activity Environment Policy Index (PA-EPI): a tool for monitoring and benchmarking government policies and actions to improve physical activity
    • Catherine B Woods
    • Liam Kelly
    • Kevin Volf
    • Peter Gelius
    • Sven Messing
    • Sarah Forberger
    • Jeroen Lakerveld
    • Nicole den Braver
    • Joanna Żukowska
    • Enrique García Bengoechea
    2022 EUROPEAN JOURNAL OF PUBLIC HEALTH

    Background Insufficient physical activity (PA) is a global issue for health. A multifaceted response, including government action, is essential to improve population levels of PA. The purpose of this study was to develop the ‘Physical Activity Environment Policy Index’ (PA-EPI) monitoring framework to assess government policies and actions for creating a healthy PA environment. Methods An iterative process was undertaken. This involved a review of policy documents from authoritative organisations, a policy audit of four European countries, and systematic reviews of scientific literature. This was followed by an online consultation with academic experts (N = 101; 20 countries, 72% response rate), and policymakers (N = 40, 4 EU countries). During this process, consensus workshops where quantitative and qualitative data alongside theoretical and pragmatic considerations were used to inform PA-EPI development. Results The PA-EPI is conceptualised as a two-component ‘policy’ and ‘infrastructure support’ framework. The two components comprise eight policy and seven infrastructure support domains. The policy domains are education, transport, urban design, healthcare, public education (including mass media), sport-for-all, workplaces and community. The infrastructure support domains are leadership, governance, monitoring and intelligence, funding and resources, platforms for interaction, workforce development, and health-in-all-policies. Forty-five ‘good practice statements’ (GPS) or indicators of ideal good practice within each domain concludes the PA-EPI. A potential eight-step process for conducting the PA-EPI is described. Conclusions Once pre-tested and piloted in several countries of various sizes and income levels, the PA-EPI GPS will evolve into benchmarks established by governments at the forefront of creating and implementing policies to address inactivity.

  • Scaled agile framework. Dealing with software process‐related challenges of a financial group with the action research approach
    • Michał Kowalczyk
    • Bartosz Marcinkowski
    • Adam Przybyłek
    2022 Pełny tekst Journal of Software-Evolution and Process

    This article reports on a domain-specific software development venture at Nordea. We explore organizational constraints, challenges, and corrective actions undertaken when scaling the agile development approach of their Core Banking Platform program. The fit and required customizations of the rather complex and rigid SAFe framework in a policy-heavy financial institution are audited against the organic growth of the program. In a qualitative study with three cycles using the Action Research method, both organizational and technical restrictions were tackled jointly with the company employees. Thirty-four potential solutions were developed—some of which turned out to be dead-ends. Ultimately, the effectiveness of prior recommendations was tested in a highly challenging implementation environment, and the list of guidelines was extended. We discovered several meeting and collaboration schemes that are not fully aligned with previous reports.

  • Scheduling on Uniform and Unrelated Machines with Bipartite Incompatibility Graphs
    • Tytus Pikies
    • Hanna Furmańczyk
    2022

    The problem of scheduling jobs on parallel machines under an incompatibility relation is considered in this paper. In this model, a binary relation between jobs is given and no two jobs that are in the relation can be scheduled on the same machine. We consider job scheduling under the incompatibility relation modeled by a bipartite graph, under the makespan optimality criterion, on uniform and unrelated machines. Unrelated machines are considered first. An FPTAS for R2|G=bipartite|Cmax is provided. We also show that for any ϵ>0,b>0 and m≥3 , there is no polynomial-time algorithm of approximation ratio O(nbp1−ϵmax) for Rm|G = bipartite |Cmax , unless P = NP. Uniform machines are considered as second. For any ϵ>0 , we show that under P = NP assumption there is no polynomial-time O(n1/2−ϵ )-approximation algorithm, even in the case of unit time jobs. We also provide a polynomial-time Σpj−−−√ -approximation algorithm for the case of jobs of arbitrary lengths pj , matching the established bound. To enrich the analysis, bipartite graphs generated randomly according to Gilbert's model Gn,n,p(n) are considered. We show that there exists an algorithm producing a schedule with makespan almost surely at most twice the optimum for a broad class of p(n) functions. To the best of our knowledge, this is the first study of randomly generated graphs in the context of scheduling in the considered model.

  • Scheduling with Complete Multipartite Incompatibility Graph on Parallel Machines: Complexity and Algorithms
    • Tytus Pikies
    • Krzysztof Turowski
    • Marek Kubale
    2022 ARTIFICIAL INTELLIGENCE

    In this paper, the problem of scheduling on parallel machines with a presence of incompatibilities between jobs is considered. The incompatibility relation can be modeled as a complete multipartite graph in which each edge denotes a pair of jobs that cannot be scheduled on the same machine. The paper provides several results concerning schedules, optimal or approximate with respect to the two most popular criteria of optimality: (makespan) and (total completion time). The problems are considered for a variety of machine types: identical, uniform and unrelated. The results consist of delimitation of the easy (polynomial) and NP-hard problems within these constraints. Also, polynomial-time exact algorithms are provided for easier problems and algorithms with a guaranteed constant worst-case approximation ratio for harder ones. In particular, there is provided a polynomial-time approximation scheme (PTAS) for scheduling with respect to on uniform machines, when the number of parts (i.e. sets of vertices constituting the mentioned graph) is bounded. The problem is addressed by developing a linear programming relaxation technique with appropriate rounding. This technique together with an exhaustive search (albeit in a manner controlled by the precision parameter) allows to provide the desired algorithm. For a PTAS is provided for the case of unit time jobs, but when the number of parts is part of the input. Interestingly, the latter result shows a connection between the considered problem of scheduling and covering problems.

  • Schronienia. Modelowanie struktur bionicznych warsztaty kreatywne
    • Agnieszka Kurkowska
    • Anna Górka
    • Magdalena Szarejko
    2022

    Warsztaty miały na celu przemyślenie i odnalezienie związków pomiędzy naturalnym ukształtowaniem krajobrazu, elementami przyrody ożywionej i nieożywionej. Uczestnicy wykonali studia rysunkowe elementów zastanych w miejscowości Piotrowo podczas zajęć terenowych. Następnie stworzono niewielkie formy gliniane, kolejno lokowane w wybranym, analizowanym uprzednio miejscu. Powstały propozycje obiektów bionicznych o możliwym architektonicznym przeznaczeniu użytkowym jako siedzib ludzkich dopasowanych do studiowanego miejsca.

  • Screw displacement pile shaft deformations measured by vibrating wire and fiber optic systems during a static load test
    • Mateusz Wiszniewski
    • Adam Krasiński
    2022 Pełny tekst

    This paper describes a full scale static load test performed on a 400 mm diameter screw displacement pile equipped with four different strain measuring systems. Three types of vibrating wire strain gauges (VWSG) were used: global - retrievable, local attached to steel pipe and local concrete embedded. The fourth system was distributed fiber optic sensors based on Rayleigh back scattering (DFOS) - three in the pile cross section. It is generally assumed that the combined cross section deforms equally. However, especially in the upper part of the pile, stress and therefore strain distribution might be non-uniform. In the case of steel tube (installed centrally in the pile axis), additional sliding effect may occur. Pile bending and local shaft imperfection may also affect strain readings, therefore using multiple gauges in a single plane might be necessary for proper result interpretation. Those assumptions were verified in the paper as the differences in readings have significant influence on final load distribution interpretation. Adaptation of several strain measurement techniques in one test allowed their applicability assessment and effectiveness verification.

  • Search for identity of Pomeranian house by means of educational activities
    • Agnieszka Kurkowska
    • Robert Idem
    2022 Pełny tekst AIP Conference Proceedings

    Architecture is a universal phenomenon and is a culture-creating field closely related to other fields of art. Hence, experiencing and feeling identity are also conditioned by the proper formation of architectural objects, which are carriers specific values which co-decide about the possibility of this experience occurring in connection with a specific place and the fulfilment of a specific need in it. In the era of ubiquitous thoughtless consumption and common avoidance of the written word, objects belonging to the material culture that architecture co-creates become essential objects in the process of conveying ideas and specific content. Belonging to a place, cultural group, community or regional community is reflected in consciously designed spatial forms. However, in order to ensure this awareness, the above-mentioned issues should be included in the general education as part of expanding knowledge about regional planning, but also the knowledge of regional architectural forms and settlement systems. The Pomeranian home experience can be related to two contrasting situations. First of all - a former Kashubian village with its regional buildings, where the house was a wooden Kashubian cottage. This architecture, arising from local conditions and culturally embedded in the consciousness of Kashubians, strengthened the sense of identification with the inhabited region and a specific place. Secondly - a contemporary Pomeranian housing estate, built up with multi-frame, prefabricated blocks. It seems that this type of development, devoid of cultural roots in regional traditions, impoverishes personal identification with the inhabited building / apartment. The space of housing estates, as well as neglected buildings in some villages await revalorization. A lost identity can be searched for by caring for valuable housing based on knowledge of architecture and regional settlement. The authors will present a publication made as part of the project entitled "ZASPA: house in a block of flats. The spaces of architecture. " In line with its assumptions, the issue of the residence of inmates in the region was raised. The book entitled "Block and hut: wandering" is an educational material for children from higher grades of primary schools. It provides knowledge about the regional form of the Kashubian house and settlement forms typical of the area. At the same time, contemporary settlement forms are shown - housing estates.

  • Seasonal Patterns and Trends in Dermatoses in Poland
    • Krzysztof Bartosz Klimiuk
    • Dawid Krefta
    • Karol Kołkowski
    • Karol Flisikowski
    • Małgorzata Sokołowska-Wojdyło
    • Łukasz Balwicki
    2022 Pełny tekst International Journal of Environmental Research and Public Health

    The amount of data available online is constantly increasing, including search behavior and tracking trends in domains such as Google. Analyzing the data helps to predict patient needs and epidemiological events more accurately. Our study aimed to identify dermatology-related terms that occur seasonally and any search anomalies during the SARS-CoV-2 pandemic. Methods: The data were gathered using Google Trends, with 69 entries between January-2010 and December-2020 analyzed. We conducted the Seasonal Mann–Kendal Test to determine the strength of trends. The month with the highest seasonal component (RSV) and the lowest seasonal component (RSV) was indicated for every keyword. Groups of keywords occurring together regularly at specific periods of the year were shown. Results: We found that some topics were seasonally searched in winter (e.g., herpes, scabies, candida) and others in summer (e.g., erythema, warts, urticaria). Conclusions: Interestingly, downward trends in searches on sexually transmitted diseases in comparison with increased infection rates reported officially show a strong need for improved sexual education in Poland. There were no significant differences in trends for coronavirus-related cutaneous symptoms during 2020. We have shown that the seasonality of dermatologically related terms searched in Poland via Google did not differ significantly during SARS-CoV-2 pandemic.

  • Segmentacja obrazów medycznych przy ograniczonej liczbie adnotacji
    • Tomasz Gruzdzis
    • Krzysztof Wicki
    • Patrycja Gładkowska
    • Tomasz Boiński
    2022

    W dziedzinie badań klinicznych i opieki zdrowotnej tradycyjne podejście w uczeniu głębokim polegające na wykorzystaniu dużych zbiorów danych jest trudne w realizacji. Przyczyną takiego stanu rzeczy są koszty znakowania obrazów medycznych, zwłaszcza w przypadku segmentacji obrazów medycznych. Jest to żmudna operacja, która zazwyczaj wymaga intensywnego znakowania pikseli wykonanego przez ekspertów – lekarzy. W tym rozdziale zaprezentowano podejście bazujące na wykorzystaniu metod uczenia maszynowego w semantycznej segmentacji obrazów medycznych. Celem badań była taka realizacja segmentacji, aby zminimalizować konieczną liczbę pełnych adnotacji na wybranym zbiorze danych. W tym celu zaproponowano użycie sieci nnU-Net. Skupiono się na zbadaniu, czy uczenie modelu z wykorzystaniem ograniczonej liczby adnotacji jest możliwe.

  • Seismic gap between buildings founded on different soil types experiencing pounding during earthquakes
    • Mahmoud Miari
    • Robert Jankowski
    2022 EARTHQUAKE SPECTRA

    Several formulas have been suggested in the literature to evaluate the minimum seismic gap that would prevent collisions between adjacent buildings during earthquakes, including those based on the absolute sum of the peak displacements (ABS), square root of the sum of the squares (SRSS), the double difference method (DDC), Australian code, and approach proposed by Naderpour et al. The aim of the present study is to evaluate the influence of the seismic gap on the behavior of buildings experiencing pounding, as well as verify the accuracy of these five formulas for structures founded on different soil types. Three buildings (4-story, 6-story and 8-story buildings) were considered and three pounding scenarios were modeled. In the first part of the study, these three pounding scenarios were analyzed by considering three different seismic gaps (1 mm, 1 cm, and 1 m). In the second part, the accuracy of the aforementioned formulas was verified for buildings founded on different soil types (hard rock, rock, very dense soil and soft rock, stiff soil, and soft clay soil). The results indicated that the seismic gap had a significant influence on the response of colliding buildings, including the peak story accelerations and pounding forces. Moreover, increasing the gap did not always lead to a reduction in the effects of pounding, unless it was large enough to eliminate structural collisions during earthquakes. In addition, all five formulas were found to provide poor estimates when considering different soil types. The ABS and the Naderpour et al. formulas were found to always be conservative, but they overestimated the minimum gap that would prevent pounding. Moreover, the DDC and Australian code formulas provided overestimate, accurate, and underestimate results, and the SRSS formula provided both accurate and overestimate results.

  • Selecting wells for an optimal design of groundwater monitoring network based on monitoring priority map: A Kish Island case study
    • Hamid Amiri
    • Sama Azadi
    • Sirus Javadpour
    • Ali Asghar Naghavi
    • Grzegorz Boczkaj
    2022 Pełny tekst Water Resources and Industry

    This paper presents a novel approach, i.e. a combination of gamma test and monitoring priority map, for optimal design of groundwater monitoring network (GMN) by considering the cumulative effects of industries, human activities, and natural factors on the groundwater quality. The proposed method was successfully applied to design an optimal network for groundwater salinity monitoring on Kish Island, Persian Gulf. The priority map of groundwater salinity monitoring was obtained based on the GALDIT index and two new factors including the average fluctuation of groundwater electrical conductivity (F) and distance from industries discharging saline effluents (P). The optimal number of monitoring wells was determined using a data analysis based on gamma test method. Then, a practical algorithm was presented to determine the optimal location of monitoring wells. Based on the results, the optimal number of monitoring wells is 110 and their location have an equitable distribution on the whole island.

  • Selection of Organic Coating Systems for Corrosion Protection of Industrial Equipment
    • Michał Drozda
    • Andrzej Miszczyk
    2022 Pełny tekst Coatings

    The most important element of corrosion protection in industrial conditions is the protective coating system. However, selecting the right coating can often be a real problem due to the sheer number of coating manufacturers and their products on the market. A quantitative approach based on the data mining technique used to analyze the obtained multi-site exposure data has been proposed. This was demonstrated by the example of the selection of a coating system to protect an industrial ball mill located in a hall for the enrichment of copper ore at the Polish company KGHM Polska Miedz S.A. A collection of 21 two-layer coating systems from different manufacturers was tested for one year. Multiple areas on the industrial ball mill, subjected to varying degrees of vibrations and abrasion, were painted. In addition, sets of samples that can be detached from the mill housing were mounted, as well as the set exposed in the hall without vibrations. The condition of the coatings after exposure was assessed using impedance spectroscopy. The obtained data from many different exposure areas were analyzed using principal components analysis (PCA). In this way, the most advantageous coating systems for the specific conditions in the hall were indicated. Additionally, on this basis, the contribution of various destructive factors, including vibrations and abrasion, to the protective properties of the tested coatings, was estimated.

  • Selectivity Tuning by Natural Deep Eutectic Solvents (NADESs) for Extraction of Bioactive Compounds from Cytinus hypocistis—Studies of Antioxidative, Enzyme-Inhibitive Properties and LC-MS Profiles
    • Gokhan Zengin
    • María de la Luz Cádiz-Gurrea
    • Álvaro Fernández-Ochoa
    • Francisco Javier Leyva-Jiménez
    • Antonio Segura Carretero
    • Malwina Momotko
    • Evren Yildiztugay
    • Refik Karatas
    • Sharmeen Jugreet
    • Mohamad Fawzi Mahomoodally
    • Grzegorz Boczkaj
    2022 Pełny tekst MOLECULES

    In the present study, the extracts of Cytinus hypocistis (L.) L using both traditional solvents (hexane, ethyl acetate, dichloromethane, ethanol, ethanol/water, and water) and natural deep eutectic solvents (NADESs) were investigated in terms of their total polyphenolic contents and antioxidant and enzyme-inhibitive properties. The extracts were found to possess total phenolic and total flavonoid contents in the ranges of 26.47–186.13 mg GAE/g and 0.68–12.55 mg RE/g, respectively. Higher total phenolic contents were obtained for NADES extracts. Compositional differences were reported in relation to antioxidant potential studied by several assays (DPPH: 70.19–939.35 mg TE/g, ABTS: 172.56–4026.50 mg TE/g; CUPRAC: 97.41–1730.38 mg TE/g, FRAP: 84.11–1534.85 mg TE/g). Application of NADESs (choline chloride—urea 1:2, a so-called Reline) allowed one to obtain the highest number of extracts having antioxidant potential in the radical scavenging and reducing assays. NADES-B (protonated by HCl L-proline-xylitol 5:1) was the only extractant from the studied solvents that isolated a specific fraction without chelating activity. Reline extract exhibited the highest acetylcholinesterase inhibition compared to NADES-B and NADES-C (protonated by H2SO4 L-proline-xylitol 5:1) extracts, which showed no inhibition. The NADES extracts were observed to have higher tyrosinase inhibitory properties compared to extracts obtained by traditional organic solvents. Furthermore, the NADES extracts were relatively better inhibitors of the diabetic enzymes. These findings provided an interesting comparison in terms of total polyphenolic content yields, antioxidant and enzyme inhibitory properties (cholinesterase, amylase, glucosidase, and tyrosinase) between traditional solvent extracts and NADES extracts, used as an alternative. While the organic solvents showed better antioxidant activity, the NADES extracts were found to have some other improved properties, such as higher total phenolic content and enzyme-inhibiting properties, suggesting functional prospects for their use in phytonutrient extraction and fractionation. The obtained results could also be used to give a broad overview of the different biological potentials of C. hypocistis.

  • Self-Organization of Graft Copolymers and Retortable iPP-Based Nanoporous Films Thereof
    • Lidia Jasinska-Walc
    • Rob Duchateau
    • Thomas Defize
    • Miloud Bouyahyi
    • Artur Rozanski
    • Lanti Yang
    • Bhaskar Patham
    • Teun Sweere
    • Sebastian Hochstädt
    • Michael Ryan Hansen
    • Katrien Bernaerts
    2022 Pełny tekst ACS Applied Polymer Materials

    Polyolefins might become inexpensive alternatives to the existing membranes based on polyethersulfone. Here we disclose the production of retortable, well-defined PP-based nanoporous membranes derived from amphiphilic graft copolymer precursors. The graft copolymers, containing a polypropylene backbone and polyester grafts, were obtained by grafting lactones, specifically δ-valerolactone and ε-caprolactone, from well-defined randomly functionalized poly(propylene-co-10-undecen-1-ol) as a macroinitiator. Depending on the composition, the graft copolymers self-assemble into droplet, cylindrical, lamellar or interconnected two-phase morphologies. Functional mesoporous iPP-based membranes were fabricated by the selective degradation of the polyester blocks of the copolymers. Their structure and morphology were studied using AFM, SEM and SAXS and solid state NMR, while the mesoporosity was assessed by nitrogen sorption experiments. The pore size of the membranes is strongly influenced not only by the volume fraction of the copolymer blocks but unexpectedly also by the topology (i.e. number of grafts) of the graft copolymer, as was confirmed by computational modeling studies using the Dynamic Density Functional Theory (DDFT) engine within the Culgi software. This work provides a conclusive answer on how the morphology of iPP-based graft copolymers is tuned by the copolymer composition and the amount and length of the grafted polyester blocks. Filtration tests and flux determination demonstrated that such structurally-well defined mesoporous products can be successfully applied for ultrafiltration processes while the chemical resistance- and sterilization tests revealed their robust performance and suitability for water purification applications.

  • Semantyczne wektory słów
    • Szymon Olewniczak
    2022

    Niniejszy rozdział stanowi wstęp do rozległego zagadnienia, jakim są semantyczne wektory słów. W szczególności skupiono się w niej na metodach automatycznego tworzenia tego typu reprezentacji na podstawie dużych zbiorów danych. Omówiono także różne możliwe interpretacje tego, czym tak naprawdę jest podobieństwo słów, oraz przedstawiono wybrane zastosowania tego typu modeli.

  • Sensing Direction of Human Motion Using Single-Input-Single-Output (SISO) Channel Model and Neural Networks
    • Sameer Ahmad Bhat
    • Muneer Ahmad Dar
    • Piotr Szczuko
    • Dalia Alyahya
    • Farhana Mustafa
    2022 Pełny tekst IEEE Access

    Object detection Through-the-Walls enables localization and identification of hidden objects behind the walls. While numerous studies have exploited Channel State Information of Multiple Input Multiple Output (MIMO) WiFi and radar devices in association with Artificial Intelligence based algorithms (AI) to detect and localize objects behind walls, this study proposes a novel non-invasive Through-the-Walls human motion direction prediction system based on a Single-Input-Single-Output (SISO) communication channel model and Shallow Neural Network (SNN). The motion direction prediction accuracy of SNN is highlighted against the other types of Machine Learning (ML) models. The comparative analysis of models in this study shows that unique human movement patterns, superimposed on received pilot radio signal, can be classified precisely by SNN, with an accuracy of approximately 89.13% compared to the other ML based models. The results of this study would guide scholars, active in developing human motion recognition systems, intrusion detection systems, or Well-being and healthcare systems, and in processes that innovate and improve processing techniques for monitoring and control.

  • Sensitive Demonstration of the Twin-Core Couplers including Kerr Law Non-Linearity via Beta Derivative Evolution
    • Adeel Asad
    • Muhammad Riaz
    • Yanfeng Geng
    2022 Pełny tekst Fractal and Fractional

    To obtain new solitary wave solutions for non-linear directional couplers using optical meta-materials, a new extended direct algebraic technique (EDAT) is used. This model investigates solitary wave propagation inside a fiber. As a result, twin couplers are the subject of this study. Kerr law is the sort of non-linearity addressed there. Because it offers solutions to problems with large tails or infinite fluctuations, the resulting solution set is more generalized than the current solution because it is turned into a fractional-order derivative. Furthermore, the found solutions are fractional solitons with spatial–temporal fractional beta derivative evolution. In intensity-dependent switches, these nonlinear directional couplers also serve as limiters. Non-linearity alters the transmission constants of a system’s modes. The significance of the beta derivative parameter and mathematical approach is demonstrated graphically, with a few of the extracted solutions. A parametric analysis revealed that the fractional beta derivative parameter has a significant impact on the soliton amplitudes. With the aid of the advanced software tools for numerical computations, the categories of semi-dark solitons, singular dark-pitch solitons, single solitons of Type-1 along with 2, intermingled hyperbolically, trigonometric, and rational solitons were established and evaluated. We also discussed sensitivity analysis, which is an inquiry that determines how sensitive our system is. A comparative investigation via different fractional derivatives was also studied in this paper so that one can easily understand the correlation with other fractional derivatives. The findings demonstrate that the approach is simple and efficient and that it yields generalized analytical results. The findings will be extremely beneficial in examining and comprehending physical issues in nonlinear optics, specifically in twin-core couplers with optical metamaterials.

  • Sensors and System for Vehicle Navigation
    • Andrzej Stateczny
    • Witold Kazimierski
    • Pawel Burdziakowski
    2022 Pełny tekst SENSORS

    In recent years, vehicle navigation, in particular autonomous navigation, has been at the center of several major developments, both in civilian and defense applications. New technologies, such as multisensory data fusion, big data processing, or deep learning, are changing the quality of areas of applications, improving the sensors and systems used. Recently, the influence of artificial intelligence on sensor data processing and understanding has emerged. Radar, LiDAR, visual sensors, sonar systems, and other sensors are mounted onboard smart and flexible platforms and on several types of unmanned vehicles in all types of environments. These technologies focusing on vehicle navigation may encounter many common scientific challenges. Particularly interesting is autonomous navigation for non-GNSS applications, such as underwater and indoor vehicle navigation. The Special Issue entitled “Sensors and System for Vehicle Navigation” focused on many aspects of vehicle navigation, such as autonomous navigation, multisensor fusion, big data processing for vehicle navigation, sensors related to science/research, algorithms/technical development, analysis tools, synergy with sensors in navigation, data fusion, and artificial intelligence methods for navigation.

  • Separation and determination of the group-type composition of modern base and lubricating oils with a wide range of polarity, especially emitted to the environment
    • Paulina Dyguła
    • Karolina Kucharska
    • Marian Kamiński
    2022 Pełny tekst JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES

    Lubricating oils are composed of base oils (>85% v/v) and enriching additives (<15% v/v). Three types of base oils may be distinguished: 1) traditional bases (obtained by low-volatile fractions from crude oil distillation refining), 2) synthetic bases (mainly poly-alpha-olefins, sometimes esters, especially succinic acid esters), 3) bases of natural origin (especially obtained from refined plant oils). The bases of natural origin are the only ones recommended for application when lubricating oil may be emitted to the environment (e.g. when the machine with an open cutting system is used). Group-type separation and analysis of group-type composition of base and lubricating oils are of significant importance in quality control and environmental monitoring. Due to the potentially wide range of polarity of the components of base and lubricating oils, group- type separation becomes a difficult separation problem. It is also a serious analytical problem due to the considerable diversity of physicochemical properties. The authors propose a new procedure for the separation and determination of the group-type composition of base and lubricating oils using thin-layer liquid chromatography in normal phase systems (abr. NP-TLC) on silica gel plates impregnated with berberine salt/in the coupling of thin-layer chromatography with flame ionization detection (abr. TLC-FID). A new, effective procedure of TLC plates impregnation with berberine sulphate was presented. The proposed procedure ensures the visualization of all groups of base oils. Extensive experimental research showed that a 2-step development procedure with application of n-hexane up to 100% height of development +15 min and further n-hexane: isopropanol: tri-fluoroacetic acid 96.25: 3: 0.75 (v: v: v) up to 75% height of development is advantageous for the group-type separation, both in TLC-FID and TLC.

  • SFEM Analysis of Beams with Scaled Lengths including Spatially Varying and Cross-Correlated Concrete Properties
    • Ewelina Korol
    2022 Pełny tekst Materials

    This paper presents the results obtained for plain concrete beams under four-point bending with spatially varying material properties. Beams of increasing length but constant depth were analyzed using the stochastic finite element method. Spatial fluctuation of a uniaxial tensile strength, fracture energy and elastic modulus was defined within cross-correlated random fields. The symmetrical Gauss probability distribution function was applied for the material properties. The shape of the probability distribution function was modified by changing the coefficient of variation in order to find its right value. The correctness of the numerical solution was verified against the experimental results of Koide et al. (1998, 2000). The stochastic FEM analysis was performed with an autocorrelation length of 40 mm and material coefficients of variation of 0.12, 0.14, 0.16, 0.20 and 0.24. The comparison between numerical outcomes and experimental results demonstrated that the coefficient of variation of 0.24 gave the best agreement when referring to the experimental mean values. On the other hand, the variation of results was better captured with the coefficient of variation of 0.16. The findings indicate that the Gauss probability distribution function with cov = 0.24 correctly reproduced the statistical size effect, but its tails needed modification in order to project experimental result variation.

  • SG
    • Krzysztof Wróblewski
    2022

    Obraz odnosi się do Stoczni Gdańskiej

  • Shaking table experimental study on pounding between adjacent structures founded on different soil types
    • Mahmoud Miari
    • Robert Jankowski
    2022 Pełny tekst Structures

    The aim of this study is to extensively investigate the effect of the soil type on the response of colliding structures based on shaking table experimental tests. Two single-storey models of steel buildings with different dynamic parameters were considered in this study. Three pounding scenarios were taken into account by applying different seismic gaps (0.5 cm, 1 cm and 1.5 cm as well as the no pounding case). First, the effect of pounding on the response of these two structures was analysed. Then, the effect of the seismic gap on the response of colliding structures was studied. Finally, the effect of soil type on the response of structures exposed to interactions was investigated. Five soil types were considered in the study, which are the five soil types defined in the ASCE 7-10 code (hard rock, rock, very dense soil and soft rock, stiff soil and soft clay soil). The results of the investigation show that pounding significantly increases the level of accelerations of structures during the whole time of vibrations as well as the peak acceleration itself. Pounding is more significant for the flexible structure than for the stiff one. Also, the seismic gap has a significant effect on the acceleration response of colliding structures. Not necessarily larger gap leads to lower responses unless it is large enough to eliminate collisions at all. Moreover, the results of the study show that the soil type has a significant effect on the response of colliding structures. The soil type effect is more significant when pounding takes place. The maximum and minimum peak acceleration differs for various soil types, pounding scenarios, seismic gaps and earthquakes.

  • Sharing research data across disciplines
    2022 Pełny tekst

    This monograph is a collection of experiences gathered by the team implementing the Bridge of Data project. However, it is not just a simple summary of the project implementation. It shows and systematizes the substantive and technical works performed by the teams and several issues related to data management itself in various disciplines, represented by members of the scientific team and other researchers from partner universities.The aim of an attempt to describe as much data as possible and the diversity thereof was to approximate to the reader of this publication both the complexity of research processes and data acquisition methods in different disciplines. Thus, it also shows various data types, formats, and methods – collection, description, and sharing. The importance of ensuring that the results of research in the form of data are not lost is increasingly emphasized. There is also a growing awareness among researchers themselves, though not everywhere and not at the same pace. Some funding bodies have defined requirements that plans for managing the data (Data Management Plans) produced during a research project should be included in grant proposals. These plans show how research data will be collected, organized, managed, and preserved during the project and after. What such a plan looks like depends on the specificity and conditions of the project

  • Shrinking-shifting and amplifying-shifting device using transformation optics
    • Hamza Madni
    • Slawomir Koziel
    • Muhammad Musavir Bilal
    • Muhammad Afzal
    • Farrukh Jaleel
    • Ahmed Sohaib
    • Wei Xiang Jiang
    2022 Pełny tekst OPTICAL AND QUANTUM ELECTRONICS

    Based on transformation optics (TO), this paper uses geometric divisions and linear coordinate transformations to design “shrinking-shifting—and reshaping”, and “amplifying-shifting—and reshaping” devices. The proposed devices can reshape the sizes and locations of the wrapped-objects inside the core-region. The shrinking-shifting device shrinks the larger object into a smaller one and shifts it to different location, whereas the shrinking-reshaping device can generate a smaller-size image with different shape located at different location. In contrast to previously designed shrinking devices, the real object wrapped inside the proposed core-region and the transformed object contains the same material properties, and the location-shifting is another feature. Here, the shifting-region is located inside the physical-space boundaries to achieve the non-negative, homogeneous, and anisotropic material properties of the proposed device, which are easier for real implementations. Thus, we further verified this concept with the amplifying-shifting and -reshaping devices for visually transformation of smaller object into bigger one placed at different location and position. We also applied active scatterer to further validate the working functionality of proposed devices. In addition, the proposed devices behave like the concentrator and (or) rotator effect in the absence of any scatterer. Our findings highlight the role of TO, suggesting directions for future research on bi-functional devices that will be useful for shrinking and amplifying devices, illusion optics, camouflage, and object protection etc.

  • Side Effects of National Immunization Program: E-Governance Support Toward Elders' Digital Inclusion
    • Magdalena Ciesielska
    • Nina Rizun
    • Anna Baj-Rogowska
    2022 Pełny tekst

    In response to the coronavirus pandemic, the European Union (EU) governments develop policies to regulate exclusive health protection actions that consider societal needs with the emphasis on elders. Given that the EU vaccination strategy uses a centralized ICT-based approach, there is little guidance on how seniors are included in national immunization programs (NIP). In this paper, we addressed a knowledge gap of the side effects of e-governance of NIP for the elderly. To fill this gap, we identified 40 side effects by analyzing online textual opinions (tweets, comments, articles) that express public perception regarding the results of the Polish NIP implementation to seniors' digital inclusion, categorized them into 8 categories and assign them to four e-governance functions. The main contribution of this paper is a better understanding of the digital divide and to provide guidelines for government policy improvement.

  • Signals Features Extraction in Radioisotope Liquid-Gas Flow Measurements using Autocorrelation Function
    • Robert Hanus
    • Marcin Zych
    • Anna Golijanek-Jędrzejczyk
    2022 Pełny tekst

    Knowledge of the two-phase flow structure is essential for the proper conduct of industrial processes. Description of liquid-gas flow regimes is possible by using of data analysis in time, frequency, or state-space domain. In this research studies, the autocorrelation function is applied for analysis of signals obtained for liquid-gas flow by use gamma-ray absorption. The experiments were carried out on the laboratory hydraulic installation fitted with Am-241 radioactive source and scintillation probe with NaI(Tl) crystal. Four types of flow regimes as plug, slug, bubble, and transitional plug - bubble were studied in this work. It was found that the selected amplitudes of the normalized autocorrelation function are helpful to recognize the flow regime.

  • Significance of Dermoscopy in Association with Clinical Features in Differentiation of Basal Cell Carcinoma and Benign Trichoblastic Tumours
    • Martyna Sławińska
    • Anna Płaszczyńska
    • Joanna Lakomy
    • Krzysztof Pastuszak
    • Wojciech Biernat
    • Monika Sikorska
    • Roman J. Nowicki
    • Michał Sobjanek
    2022 Pełny tekst Cancers

    Background: Although basal cell carcinoma (BCC) can, in the majority of cases, be diagnosed based on clinical and dermoscopic assessment, a potential overlap with benign adnexal skin tumours seems to exist, including trichoblastic tumours (TT). Methods: Retrospective analysis of clinical and dermoscopic features of benign TT and BCC cases was performed to develop a diagnostic algorithm with a potential utility in clinical practice. Results: In the study, 502 histopathologically confirmed BCC cases were compared with 61 TT (including 44 TB (72.13%), 10 TE (16.39%) and 7 DTE (11.48%]). Patients in the BCC group were statistically older (mean age was 71.4 vs. 64.4 years, respectively; p = 0.009). BCC presented generally as larger tumours (mean tumour size 11.0 vs. 8.2 mm for the TT group; p = 0.001) and was more frequently associated with clinically visible ulceration (59.4% vs. 19.7%, respectively; p < 0.001). Comparison of lesion morphology, clinically visible pigmentation, and anatomical location did not show significant differences between the analysed groups. Dermoscopically visible ulceration was significantly more common in the BCC group compared to the TT group (52.2% vs. 14.8%; p < 0.0001). Pigmented structures, specifically brown dots and brown globules, were significantly more prevalent in the TT group (32.8% vs. 11.4%; p = 0.0001 and 29.5% vs. 8.2%; p <0.0001). Similarly, TT more commonly than BCC showed the presence of cloudy/starry milia-like cysts (26.2% vs. 11.6%; p = 0.0031) and yellow globules (16.4% vs. 7.2%; p = 0.033). Conclusions: Despite differences in frequency of clinical and dermoscopic features between BCC and TT in the studied group, differential diagnosis based on these variables is not reliable. Histopathological examination remains a diagnostic gold standard in differentiation of BCC and TT.

  • Silicon oxycarbide-tin nanocomposite derived from a UV crosslinked single source preceramic precursor as high-performance anode materials for Li-ion batteries
    • Dominik Knozowski
    • Pradeep Vallachira Warriam Sasikumar
    • Romain Dubey
    • Marcel Aebli
    • Kostiantyn V. Kravchyk
    • Grzegorz Trykowski
    • Maksym V. Kovalenko
    • Thomas Graule
    • Monika Wilamowska-Zawłocka
    • Gurdial Blugan
    2022 Pełny tekst Applied Materials Today

    In this work, we report an innovative and facile UV light-assisted synthesis of a nanocomposite based on silicon oxycarbide (SiOC) and tin nanoparticles. SiOC ceramic matrix, containing a conductive free carbon phase, participates in lithium-ion storage, and buffers the volume changes of Li-alloying/de-alloying material. The reported synthesis procedure through a polymer-derived ceramic route involves the preparation of a single-source precursor by UV crosslinking of a preceramic polymer in the presence of a tin precursor. Pyrolysis of this starting precursor at 1000 °C leads to a homogenous distribution of tin nanoparticles (25–35 nm) within the SiOC ceramic matrix, which is crucial for electrochemical stability of the material. SiOC/Sn nanocomposite tested as an anode for Li-ion battery exhibits high reversible capacity values (603 mAh g−1 at the current density of 74.4 mA g−1), outstanding rate capability (524 mAh g−1 at 2232 mA g−1), and superior stability (494 mAh g−1 after 250 charge/discharge cycles).

  • Simple Millimeter Wave Identification System Based on 60 GHz Van Atta Arrays
    • Kamil Trzebiatowski
    • Mateusz Rzymowski
    • Łukasz Kulas
    • Krzysztof Nyka
    2022 Pełny tekst SENSORS

    The paper presents a proof-of-concept of a millimeter-wave identification system based on Van Atta array tags in the 60 GHz band. For interrogation of the tags, a vector network analyzer and a measurement transceiver were employed in alternative test configurations. The design, fabrication and measurements of co- and cross-polarized Van Atta arrays are presented in the paper. They can be treated as simple chipless RFID tags with frequency-response-based identification. Tags with various resonance frequencies are designed by scaling an optimized base model. The designed 57–67 GHz co-polarized and cross-polarized tags have small dimensions of approximately 23 mm 21 mm and 40 mm 25 mm, and they exhibit radar cross-section (RCS) levels of 16 dBsm and 21 dBsm, respectively. Owing to the retrodirective properties of Van Atta arrays, the RCS can be maintained at a high level within a broad range of angles of incidence. The system was validated in an anechoic chamber where the spectral responses of all the manufactured tags can be clearly distinguished from the environment, enabling their identification. Tests in a reflective environment were also performed, and they have shown that only the cross-polarized tags could be detected and identified in the presence of reflections from the tags’ surroundings.

  • Simple synthesis route for fabrication of protective photo‐crosslinked poly(zwitterionic) membranes for application in non‐enzymatic glucose sensing
    • Adrian Olejnik
    • Jakub Karczewski
    • Anna Dołęga
    • Katarzyna Siuzdak
    • Adam Cenian
    • Katarzyna Grochowska
    2022 Pełny tekst JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS

    This work focuses on the fabrication of non-enzymatic glucose sensing materials based on laser-formed Au nanoparticles embedded in Ti-textured substrates. Those materials possess good catalytic activity toward glucose oxidation in 0.1 × phosphate buffered saline as well as resistance to some interferants, such as ascorbic acid, urea, and glycine. The electrodes are further coated with three different polymers, that is, Nafion, photo-crosslinked poly(zwitterions) based on sulfobetaine methacrylate, and a hybrid membrane consisting of both polymers. Both the optimal integrity of the material and its catalytic activity toward glucose oxidation were maintained by the hybrid membranes with a large excess of poly(zwitterions) (mass ratio 20:1). The chemical structures of the as-formed membranes are confirmed by Fourier transform infrared spectroscopy. Due to the zwitterionic nature of the coating, the electrodes are resistant to biofouling and maintain electrochemical activity toward glucose for 4 days. Moreover, due to the synergistic effect of both Nafion and poly(zwitterions), the interference from the two compounds, namely, from acetylsalicylic acid and acetaminophen, was diminished. Besides the presence of polymer membranes, the electrode possesses a sensitivity of 36.8 μA cm−2 mM−1 in the linear range of 0.4–12 mM, while the limit of detection was estimated to be 23 μM. Finally, the electrodes are stable, and their response is not altered even by 1,000 bending cycles.

  • SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
    • Przemysław Sorn
    • Mateusz Sondej
    • Jarosław Górski
    2022 Pełny tekst

    Fuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing for its optimization.

  • Simplified Numerical Model for Transient Flow of Slurries at Low Concentration
    • Katarzyna Weinerowska-Bords
    • Apoloniusz Kodura
    • Michał Kubrak
    2022 Pełny tekst ENERGIES

    Rapid transients are particularly dangerous in industrial hydro-transport systems, where solid-liquid mixtures are transported via long pressure pipelines. A mathematical description of such flow is difficult due to the complexity of phenomena and difficulties in determining parameters. The main aim of the study was to examine the influence of the simplified mixture density and wave celerity description on satisfactory reproduction of pressure characteristics during the transient flow of slurry at low concentrations. The paper reports and discusses the selected aspects of experimental and numerical analyses of transient slurry flow in a polyethylene pipe. The experiments were conducted by using the physical model of a slurry’s transportation pressure. The aim of the experiments was to determine the wave celerity during a transient flow in slurries. A low concertation of slurries, which was used during experiments, is typical for one of the biggest slurry networks in Poland. A comparison of the effects of different wave celerity descriptions was performed. The research reported that the theoretical formulas for slurry wave celerity and mixture density were not sufficiently accurate to obtain satisfactory compliance between calculations and observations. To improve the model, the experimental values of wave celerity and the concept of equivalent mixture density have been applied to indirectly consider the influence of variable mixture parameters. With such modifications, the calculated pressure characteristics in all analyzed episodes demonstrated satisfactory compliance with observations. The simplified approach proved to be effective in properly reproducing the intensity and frequency of rapid pressure changes.

  • Simulation of hybridized nanofluids flowing and heat transfer enhancement via 3-D vertical heated plate using finite element technique
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    • Hasan Shahzad
    • Amjad Ali Pasha
    • Mohammad Adil
    2022 Pełny tekst Scientific Reports

    The present study probed the creation of heat energy and concentrating into Newtonian liquids across vertical 3D-heated plates. The role of the Soret and Dufour theories in concentrating and energy formulas is discussed. The role of hybrid nanoparticles is introduced to illustrate particle efciency in terms of solute and thermal energy. It is removed a viscous dissipation process and a changing magnetic feld. The proposed approach is motivated by the need to maximize solute and thermal energy uses in biological and industrial domains. The constructed system of (partial diferential equations) PDEs includes concentration, momentum, and thermal energy equations within various thermal characteristics. Transformations are used to formulate the system of (ordinary diferential equations) ODEs for solution. To assess various features vs various variables, a Galerkin fnite element approach is used. Motion into nanoscale components is shown to be smaller than motion into hybrid nanoparticles. Furthermore, fuctuations in heat energy and solute particle counts are seen in relation to changes in Soret, Eckert, magnetic, and Dufour numbers. The basic fnding is that the generation of thermal energy for hybridized nanomaterials is much higher.

  • Simulations of the Derecho Event in Poland of 11th August 2017 Using WRF Model
    • Mariusz Figurski
    • Grzegorz Nykiel
    2022 Pełny tekst

    This series contains datasets related to the forecasting of a severe weather event, a derecho, in Poland on 11 August 2017. The simulations were conducted using the Weather Research and Forecasting (WRF) model version 4.2.1 with different initial and boundary conditions of the pressure and model levels derived from 5 global models: Global Forecast System (GFS), Global Data Assimilation System (GDAS), European Centre for Medium-Range Weather Forecasts (ECMWF), and ERA5. Each simulation, shared as a separate dataset, was performed for two starting hours: at 00:00 and 12:00 UTC. The datasets contain about 280 meteorological parameters stored as 2D or 3D fields with high-spatial (2.5 km and 0.5 km domains) and temporal (10 minutes) resolutions. The three-dimensional fields are calculated at 50 levels up to 50 hPa. All data are stored in easily accessible NetCDF files.

  • Simultaneous removal of heavy metals and dyes in water using a MgO-coated Fe3O4 nanocomposite: Role of micro-mixing effect induced by bubble generation
    • Manoj Panayamthatta Rayaroth
    • Dasom Oh
    • Chung-seop Lee
    • Yoon-seok Chang
    2022 Pełny tekst CHEMOSPHERE

    This study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly Fe3O4@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb2+) and a dye, rhodamine B (RhB). The addition of H2O2 into the system enabled the self-mixing of the aqueous solution containing Fe3O4@MgO through the generation of bubbles. This system showed an excellent removal efficiency of 99% in just 15 min for Pb2+ and 120 min for RhB, which is far better than the control experiment (without H2O2). The cation exchange mechanism dominated in the removal of heavy metals, while the adsorptive removal of dye proceeded through the H-bonding between Mg(OH)2 and dye molecules. The removal efficiency increased exponentially with the increase of H2O2 at the optimal concentration of 5% and it was effective over a wide pH range. Moreover, the performance of the Fe3O4@MgO-H2O2 system was verified for other heavy metals such as Cd, Ni, Zn, Co, and Cu, demonstrating that the Fe3O4@MgO-H2O2 system can be widely implemented in the treatment of real water matrices contaminated with heavy metals and organic dyes.

  • Single and Series of Multi-valued Decision Diagrams in Representation of Structure Function
    • Michal Mrena
    • Miroslav Kvassay
    • Stanisław Czapp
    2022

    Structure function, which defines dependency of performance of the system on performance of its components, is a key part of system description in reliability analysis. In this paper, we compare two approaches for representation of the structure function. The first one is based on use of a single Multi-valued Decision Diagram (MDD) and the second on use of a series of MDDs. The obtained results indicate that the series of MDDs can be more efficient than a single MDD in case of series-parallel systems, which belong to the most fundamental types of topologies studied by reliability engineers.

  • Single-phase, Five-level Inverter with SPWM-Based Neutral Point Voltage Balancing Scheme
    • Dmytro Kondratenko
    • Arkadiusz Lewicki
    • Charles Odeh
    2022 Pełny tekst

    Multilevel inverter topologies provide several advantages over two-level inverter configuration. These benefits are the reason for the growing interest in multilevel topologies among research society. One of the most popular topological concepts (diode and active switch clamping) requires neutral-point potential balancing due to series-connected capacitor banks across the input dc link in such derived inverter configurations. This paper presents a Sinusoidal PWM (SPWM) scheme that ensures balanced and reduced input capacitor voltages' variations in single-phase T-type inverter. Comparison analyses with existing carrier-based pulse-width modulation methods are provided. Simulation results are provided which showcase the effectiveness of the control approach. Experimental validation of these results was provided with a five-level single-phase T-type VSI; that supplies single-phase RL load.

  • Size effect at aggregate level in microCT scans and DEM simulation – Splitting tensile test of concrete
    • Jan Suchorzewski
    • Michał Nitka
    2022 Pełny tekst ENGINEERING FRACTURE MECHANICS

    The paper describes an experimental and numerical study of size effect on concrete cylindrical specimens in splitting tensile test. Own experimental campaign was performed on specimens with 5 various diameters from D = 74, 105, 150, 192 and 250 mm with hardboard loading strips (distributed load according to standard methods) scaled proportionally to the specimen diameter. The crack opening-control system was applied to obtain the post-peak behaviour of all tested specimens including catastrophic behaviour (snap-back). The tested specimens at a certain point were unloaded and scanned with novel high-resolution micro tomography to analyse the macro cracks and phenomena like aggregate breakage, crack branching etc. at the aggregate level. Based on realistic mesostructure the discrete element method (DEM) 2D model of 3 specimens with diameters of D = 74, 150 and 250 mm were constructed and tested. The fracture was analysed at macro and micro-level in DEM and directly compared with microCT scans. DEM simulations revealed additional information related to the loss of material strength and ductility with increasing specimen size (size effect). The simulation and experimental results were in good agreement.

  • Skills mismatch in the context of technological change
    • Franciszek Kutrzeba
    2022

    The main purpose of this dissertation is to assess the perception asymmetry of smart skills and formal education in ICT based economy. In other words, the goal of this research is to assess perceptions of smart skills and competences in the context of technological change from the perspectives of employers and students in Poland. Determining the fore-mentioned relationship gives insight into the hypothetical perception asymmetry for demanded smart skills in an ICT-based economy with possible practical implications for policymakers and educators. I have defined the following research questions: 1. What is the interrelation of perceptions on smart skills and competences between Polish higher education students and employers in Poland? 2. What is the significance of formal education in the context of recent technological change?