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Gdańsk University of Technology

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  • Mechanical-Level Hardware-In-The-Loop and Simulation in Validation Testing of Prototype Tower Crane Drives
    • Michał Michna
    • Filip Kutt
    • Łukasz Sienkiewicz
    • Roland Ryndzionek
    • Grzegorz Kostro
    • Dariusz Karkosiński
    • Bartłomiej Grochowski
    2020 Full text ENERGIES

    In this paper, the static and dynamic simulations, and mechanical-level Hardware-In-the-Loop (MHIL) laboratory testing methodology of prototype drive systems with energy-saving permanent-magnet electric motors, intended for use in modern construction cranes is proposed and described. This research was aimed at designing and constructing a new type of tower crane by Krupiński Cranes Company. The described research stage was necessary for validation of the selection of the drive system elements and confirmation of its compliance with applicable standards. The mechanical construction of the crane was not completed and unavailable at the time of testing. A verification of drive system parameters had to be performed in MHIL laboratory testing, in which it would be possible to simulate torque acting on the motor shaft. It was shown that the HIL simulation for a crane may be accurate and an effective approach in the development phase. The experimental tests of selected operating cycles of prototype crane drives were carried out. Experimental research was performed in the LINTE^2 laboratory of the Gdańsk University of Technology (Poland), where the MHIL simulator was developed. The most important component of the system was the dynamometer and its control system. Specialized software to control the dynamometer and to emulate the load subjected to the crane was developed. A series of tests related to electric motor environmental parameters was carried out.

  • Mechaniczne Metody Badań Materiałów
    • Wiktoria Wojnicz
    • Edmund Wittbrodt
    2020 Full text

    W podręczniku zawarto opis Laboratorium Wytrzymałości Materiałów znajdującego się w Katedrze Mechaniki i Mechatroniki na Wydziale Mechanicznym Politechniki Gdańskiej oraz instrukcje do szesnastu ćwiczeń laboratoryjnych dla studentów wszystkich kierunków studiów oferowanych na Wydziale. Ćwiczenia dotyczą zagadnień związanych ze statycznymi i dynamicznymi próbami niszczącymi, badań materiałów na ściskanie i rozciąganie, badań twardości, udarności, wytrzymałości zmęczeniowej i propagacji pęknięcia zmęczeniowego oraz badań lin stalowych, prób technologicznych i badań niszczących złączy spawanych metali. Są to badania odnoszące się do metali pracujących nie tylko w temperaturze otoczenia, ale także w podwyższonej temperaturze. W opisach poszczególnych ćwiczeń podano cel prowadzonych badań, podstawowe definicje, metody realizacji badań ze szczególnym omówieniem próbek do badań, maszyn i urządzeń wytrzymałościowych niezbędnych do realizacji badań oraz sposobu analizy i opracowywania wyników. Podano również wykaz polskich i europejskich norm, według których prowadzone są badania.

  • Mechanizm współpracy z gruntem pali prefabrykowanych wbijanych w świetle próbnych obciążeń pali oprzyrządowanych
    • Adam Krasiński
    • Kazimierz Gwizdała
    • Tomasz Kusio
    • Paweł Więcławski
    • Mateusz Wiszniewski
    2020 Full text Inżynieria Morska i Geotechnika

    Opis badań i wyniki próbnych obciążeń statycznych dwóch pali prefabrykowanych wbijanych oprzyrządowanych w aparaturę do pomiaru rozkładu siły osiowej wzdłuż trzonu pala. Analiza wpływu czasu i procesu wbijania na charakterystykę osiadania pali prefabrykowanych wbijanych. Identyfikacja siły rezydualnej w palu prefabrykowanym wbijanym i jej wpływ na interpretację pomiarów ekstensometrycznych w próbnym obciążeniu pala. Wnioski na temat problemów w interpretacji wyników badań pali prefabrykowanych wbijanych oprzyrządowanych pomiarowo.

  • Membrane technologies assisting plant-based and agro-food by-products processing: A comprehensive review
    • Roberto Castro-Muñoz
    • Grzegorz Boczkaj
    • Emilia Gontarek
    • Alfredo Cassano
    • Vlastimil Fíla
    2020 Full text TRENDS IN FOOD SCIENCE & TECHNOLOGY

    Background Nowadays, membrane-based technologies (e.g. microfiltration, ultrafiltration, nanofiltration, membrane distillation, and pervaporation) have demonstrated to meet the requirements to be involved in different food and bioproduct processes. Scope and approach Several applications have been developed, including either separation, recovery or concentration of bioactive molecules from agro-food products and by-products, treatment of natural extracts, recovery of aromas from natural and processed products, production of non-alcoholic beverages, as the most popular ones. Therefore, the goal of this review is to give a comprehensive outlook of the latest developments focused on the separation, fractionation and concentration of several bioactive compounds contained in their original sources, as well as the food processes-assisted by membrane technologies. Key findings and conclusions Throughout this review, ongoing literature has been analysed, discussing the relevant insights according to the type of membrane-based separation process, properties of molecules, membrane features and key factors influencing the separation performance of those technologies. Specific applications have been analysed and discussed, highlighting typical advantages and drawbacks over conventional technologies.

  • Membranes for toxic- and heavy-metal removal
    • Roberto Castro-Muñoz
    • Emilia Gontarek
    • Alberto Figoli
    2020

    Since time ago, membranes have greatly attracted the attention of researchers for different types of water-treatment applications, such as wastewater treatment, water purification, removal of microorganisms, chemical compounds, and heavy metals. Nowadays, one of the current challenges of research community definitely deals with the removal of toxic and heavy metals from water. In this regard, the current chapter provides enough inputs about the current advances and approaches of the use of membranes for such removal task, thereby addressing the highlighted literature survey of using polymeric and nanocomposite membranes for heavy-metal removal. Moreover, it gives up-to-date information related to those novel nanocomposite membranes and their contribution for water-treatment applications.

  • Meso-mechanical modelling of damage in concrete using discrete element method with porous ITZs of defined width around aggregates.
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2020 Full text ENGINEERING FRACTURE MECHANICS

    Artykuł omawia wyniki obliczeń numerycznych pękania dla betonu stosując metodę elementów dyskretnych. Beton był opisany jako materiał 4-fazowy i był poddany zginaniu. W obliczeniach uwzględniono strefy ITZ o skończonej szerokości dookoła wszystkich ziaren kruszywa. Nacisk położono na przebieg mikropęknięć przy kruszywie. Wyniki porównano bezpośrednio z doświadczeniami. Obliczenia wykonano także dla szorstkich ziaren kruszywa. Wyniki zaprezentowane w artykule oferują nową perspektywę w zrozumieniu procesu powstawanie pęknięć w obciążonym betonie.

  • Mesophilic and thermophilic dark fermentation course analysis using sensor matrices and chromatographic techniques
    • Edyta Słupek
    • Patrycja Makoś
    • Karolina Kucharska
    • Jacek Gębicki
    2020 Full text CHEMICAL PAPERS

    Production of biofuels from biomass is expected to benefit the society and the environment. At present, bio waste residues processing includes hydrolysis, dark fermentation, photofermentation, pyrolysis, gasification, and chemical synthesis. As the composition and the chemical structure of organic substances affect the efficiency of mentioned processes, it is believed that the glucose concentration is a crucial parameter for the evaluation of the efficiency of biological processes. Also, the control of by-products formulated during each stage of biomass processing affects the course of dark fermentation. Therefore, model processes regarding mesophilic and thermophilic dark fermentation were carried out. Glucose as a sole carbon source was applied as the fermentation broth and Faloye-pretreated activated municipal wastewater sludge was introduced as the source of sporulating microorganisms. Production of hydrogen and methane was controlled by means of sensor matrices. Obtained results are comparable to those obtained using the standard method based on gas chromatography and indicate the suitability of their application for online routine analyses of hydrogen and methane during fermentation processes. In addition, the fermentation broth was also examined by means of gas and liquid chromatography in the scope of glucose reduction, and generation of volatile fatty acids and phenols.

  • Metal ion directed template synthesis using 2-acetyl-1,3-indandione and ethylenediamine: steric and electronic restrictions
    • Anife Ahmedova
    • Sonya Zareva
    • Anna Dołęga
    2020 MENDELEEV COMMUNICATIONS

    A template synthesis using 2-acetyl-1,3-indandione and ethylenediamine results in formation of octahedral Ni complex, whose crystal structure has been resolved using single crystal X-ray diffraction. The structure indicates that only exocyclic enolic oxygen atom of the triketone takes part in the condensation with ethylenediamine.

  • Metal-Organic Framework (MOF)/Epoxy Coatings: A Review
    • Farzad Seidi
    • Maryam Jouyandeh
    • Mohsen Taghizadeh
    • Ali Taghizadeh
    • Henri Vahabi
    • Sajjad Habibzadeh
    • Krzysztof Formela
    • Mohammad Saeb
    2020 Full text Materials

    Epoxy coatings are developing fast in order to meet the requirements of advanced materials and systems. Progress in nanomaterial science and technology has opened a new era of engineering for tailoring the bulk and surface properties of organic coatings, e.g., adhesion to the substrate, anti-corrosion, mechanical, flame-retardant, and self-healing characteristics. Metal-organic frameworks (MOFs), a subclass of coordinative polymers with porous microstructures, have been widely synthesized in recent years and applied in gas and energy storage, separation, sensing, environmental science and technology, and medicine. Nevertheless, less attention has been paid to their performance in coatings. Well-known as micro- and nanoporous materials, with a tailorable structure consisting of metal ions and organic linkers, MOFs have a huge loading capacity, which is essential for the delivery of corrosion inhibitors. This review paper attempts to highlight the importance of epoxy/MOF composites for coating applications. A particular emphasis was explicitly placed on the anti-corrosion, flame-retardant, mechanical, and dielectric properties of epoxy/MOF coatings.

  • Method of estimating the rolling resistance coefficient of vehicle tyre using the roller dynamometer
    • Adrian Soica
    • Adian Budala
    • Vlad Monescu
    • Sławomir Sommer
    • Wojciech Owczarzak
    2020 PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING

    The tendency in the past few years has been to introduce tyres with lower rolling resistance coefficients to the market. This paper presents a mathematical method for determining the rolling resistance coefficients variation depending on the speed. The method uses power balance which results from automobile dynamics while rolling on chassis dynamometer. The rolling resistance coefficients of tyres obtained through ‘drum test method’, for which the rolling resistance coefficients variation is known in terms of vehicle speed, are considered as reference values, while than rolling resistance coefficients of tyres obtained through ‘MAHA roller dynamometer’ using the recorded lost drag power in the roll-out phase on the stand are considered as tested values. The rolling resistance coefficients variation could be determined up to the maximum permissible speed of the tyre, for all wheels trained on the stand and not just for one tyre, as determined in laboratory conditions. The test conditions are similar to those in real road conditions, where the temperature of the environment and wheels cannot be controlled. The values obtained by the authors’ proposed method were compared with the values obtained by the ‘drum test method’. The main contribution of the proposed method is to estimate the rolling resistance coefficients without using a very expensive test facility.

  • Methodology for Carrying Out Measurements of the Tombolo Geomorphic Landform Using Unmanned Aerial and Surface Vehicles near Sopot Pier, Poland
    • Cezary Specht
    • Oktawia Lewicka
    • Mariusz Specht
    • Paweł Dąbrowski
    • Paweł Burdziakowski
    2020 Full text Journal of Marine Science and Engineering

    The human impact on the ecosystem has been particularly evident in the last century; it transforms the Earth’s surface on an unprecedented scale and brings about irreversible changes. One example is an oceanographic phenomenon known as a tombolo, i.e., a narrow belt connecting the mainland with an island lying near the shore formed as a result of sand and gravel being deposited by sea currents. The phenomenon contributes to an increase in the biogenic substance content in the littoral zone, which leads to increased cyanobacteria blooming in the summer period. Moreover, the debris accumulation in the littoral zone results in the mud formation, which makes the beach landscape less attractive. One of the main features of the tombolo phenomenon is its variability of shape, which includes the form of both the shore and the seabed adjacent to it. Therefore, to describe its size and spatio-temporal variability, it is necessary to apply methods for geodetic (the land) and hydrographic (the sea) measurements that can be carried out in different ways. The aim of the paper is to present the methodology for carrying out measurements of the tombolo oceanographic phenomenon using Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicles (USV) on the example of a waterbody adjacent to the Sopot pier. It also presents the results of surveys carried out in November 2019 within this area. The study demonstrated that the integration of two measuring devices whose development began in the second decade of the 20th century, i.e., UAVs and USVs, enables accurate (even up to several centimeters) and reliable determination of the scale and variability of the phenomena occurring in the littoral zone.

  • Methodology for hospital design in architectural education
    • Rafał Janowicz
    2020 Full text World Transactions on Engineering and Technology Education

    The architecture of a hospital should be a response to strong user requirements. Recommendations on how to shape the environment of such facilities are highly complex, integrating guidelines from many fields of science. If contradictions between them exist, the designer is required to set priorities for spatial activities. This issue is particularly important during architectural education. The learning process should include projects with a high level of complexity, thus providing students with the opportunity to prepare works in planning medical facilities. These works should include consideration that medical architecture is a multifaceted task, both in theoretical and practical terms. In this case, the methodology of improvement is a helpful teaching tool. The intent in producing this article was to illustrate the possibility of using process analysis to approximate the performance of medical procedures in the teaching process and their impact on the design of hospital buildings as complex engineering facilities.

  • Methylation effect in e−— scattering on methyl-substituted ethylenes
    • Sylwia Stefanowska-Tur
    • Czesław Szmytkowski
    • Elżbieta Ptasińska-Denga
    • Paweł Możejko
    2020 Full text Journal of Physics : Conference Series

    Methylation effect has been observed and studied in electron-scattering from selected hydrocarbon molecules. In measured total cross section (TCS) functions we have noticed energy shifts and changes in the intensity of observed structures.

  • Metoda lokalizowania sensorów IoT przy użyciu mobilnej stacji bazowej
    • Jacek Stefański
    • Jarosław Sadowski
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule opisano innowacyjną metodę lokalizowania obiektów dla potrzeb Internetu rzeczy (IoT). Przedstawiono matematyczną analizę metody. Opisano również wyniki kompleksowych badań symulacyjnych efektywności pracy zaproponowanej metody dla wybranych parametrów radiowej sieci sensorowej.

  • Metodologia badania skrzyni biegów z wykorzystaniem układu hydraulicznego jako hamowni
    • Marcin Bąk
    • Piotr Patrosz
    2020 Full text Napędy i Sterowanie

    W artykule przedstawiono metodologię prowadzenia badań mechanicznej skrzyni biegów. Sposób prowadzenia pomiarów zaprezentowano na przykładzie badań wybranej przekładni. Przedstawiono i opisano różne konfiguracje stanowiska badawczego wykorzystującego układ hydrauliczny, który pełnił funkcję hamowni. Zawarto opis konstrukcji prototypowej przekładni będącej obiektem badań. Ponadto omówiono przykładowe charakterystyki uzyskane w ramach przeprowadzonych testów.

  • Metodyka systematycznego przeglądu literatury w zakresie konkursów o nagrody jakości opartych na modelach doskonałości
    • Anna Wendt
    2020

    Model doskonałości można zdefiniować jako zbiór zasad kompleksowej oceny organizacji , który często wykorzystywany jest jako podstawa konkursów jakości. Celem niniejszego referatu jest systematyczny przegląd literatury o tematyce konkursów jakości opartych na modelach doskonałości, szczególnie związanych z modelem EFQM – modelem europejskim. Podczas badań wykorzystano trzy bazy literaturowe dostępne na Politechnice Gdańskiej – Taylor&Francis, Web of Science oraz Scopus. Za pomocną powyższej metody zdiagnozowany został stan faktyczny związany z konkursami na świecie. Uzyskano informacje na temat: liczby publikacji o tej tematyce, rozpoznawalności modeli doskonałości na świecie oraz o możliwościach ich wykorzystania. Ukazano lukę badawczą związaną z konkursami o charakterze krajowym i regionalnym.

  • Microcrystalline Cellulose Management in the Production of Poly(ether-urethane)s- Structure, Morphology, and Thermal Characteristic
    • Paulina Kasprzyk
    • Kamila Błażek
    • Janusz Datta
    2020 FIBERS AND POLYMERS

    In response to the demand of polymer industry for reducing the use of synthetic chemicals, eco-friendly materials are investigated. In the presented study, bio-based poly(ether-urethane)s were prepared by using microcrystalline cellulose (MCC) and polyether polyol and 1,3-propanediol derived from corn sugar. A step towards sustainability was taken by incorporating bio-based compounds and cellulose, consequently, bio-waste are utilized in a smart way. The new materials were synthesized via prepolymer method, while the cellulose fibers were added after the reaction. Structural studies of biocomposites were realized by FTIR technique. The number of free and hydrogen-bonded carbonyl groups was determined based on the deconvolution of C=O band. Crystallinity was assessed on the basis of X-ray diffraction analysis. The influence of the MCC content on the thermo-mechanical, thermal and selected mechanical properties has been demonstrated. Results obtained by SEM method showed that the higher degree of reinforcement led to the formation of aggregates reflecting their poor dispersion in the polymer matrix. It may probably result from the relatively weaker interaction between MCC and PU matrix. On the other hand, it was found that the incorporation of fibers improved the thermo-mechanical and thermal properties of the prepared materials. This work provides an effective way of using bio-renewable chemicals in the polyurethane industry without using additional processing apparatus and chemical processes. The used method makes it possible to obtain materials with high bio-content and satisfactory thermal characteristic.

  • Microencapsulation of fish oil – determination of optimal wall material and encapsulation methodology
    • Natalia Łozińska
    • Agnieszka Głowacz-Różyńska
    • Wojciech Artichowicz
    • Yuanqi Lu
    • Christian Jungnickel
    2020 JOURNAL OF FOOD ENGINEERING

    For the first time, we present a meta-analysis of experimental and literature data to determine which microencapsulation methodology, and which wall material are best suited to protect fish oil. Our analysis covered a period of several decades of research (1984–2018). The analysis was conducted on 196 literature data-points, and 16 data-points determined experimentally for this publication. PLS regression was used to determine the influence of the predictors, with a variety of rational (k-means, Kohonen SOM, and Kennard-Stone) and random training/test division methods. Analysis of the applicability domain, determined by calculating the convex hull of the points, clearly showed that rational division methods are better than random division. It was found, that spray-granulation is best suited to protect fish oil. On the other hand, the commonly cited method of spray-drying performs quite badly. In addition, we found that the best wall materials are protein + lipid + carbohydrate and protein + lipid. The commonly used protein + carbohydrate again fared poorly. Meta-analysis such as these are crucial for the overview of methods and materials employed in the design of functional foods.

  • Microscale diamond protection for a ZnO coated fiber optic sensor
    • Monika Kosowska
    • Paulina Listewnik
    • Daria Majchrowicz
    • Michał Rycewicz
    • Mikhael Bechelany
    • Yafit Fleger
    • Mingzhou Chen
    • Dror Fixler
    • Kishan Dholakia
    • Małgorzata Szczerska
    2020 Full text Scientific Reports

    Fiber optic sensors are widely used in environmental, biological and chemical sensing. Due to the demanding environmental conditions in which they can be used, there is a risk of damaging the sensor measurement head placed in the measuring field. Sensors using nanolayers deposited upon the fiber structure are particularly vulnerable to damage. A thin film placed on the surface of the fiber end-face can be prone to mechanical damage or deteriorate due to unwanted chemical reactions with the surrounding agent. In this paper, we investigated a sensor structure formed with a Zinc Oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) on the tip of a single-mode fiber. A nanocrystalline diamond sheet (NDS) attached over the ZnO is described. The diamond structure was synthesized in a Microwave Plasma Assisted Chemical Vapor Deposition System. The deposition processes of the nanomaterials, the procedure of attaching NDS to the fiber end-face covered with ZnO, and the results of optical measurements are presented.

  • Microscopic traffic simulation models for connected and automated vehicles (CAVs) – state-of-the-art
    • Paweł Gora
    • Cristos Kartakazas
    • Arkadiusz Drabicki
    • Faqhrul Islam
    • Piotr Ostaszewski
    2020 Full text Procedia Computer Science

    Research on connected and automated vehicles (CAVs) has been gaining substantial momentum in recent years. However, thevast amount of literature sources results in a wide range of applied tools and datasets, assumed methodology to investigate thepotential impacts of future CAVs traffic, and, consequently, differences in the obtained findings. This limits the scope of theircomparability and applicability and calls for a proper standardization in this field of research. The objective of this paper is tocontribute towards bridging this gap by providing a summary of the state-of-the-art literature review regarding microscopicsimulation models for connected and automated vehicles.

  • Microstructure and Mechanical Properties of Carboxylated Nitrile Butadiene Rubber/Epoxy/XNBR-grafted Halloysite Nanotubes Nanocomposites
    • Seyed Paran
    • Ghasem Naderi
    • Heydar Mosallanezhad
    • Elnaz Movahedifar
    • Krzysztof Formela
    • Mohammad Saeb
    2020 Full text Polymers

    The effect of various amounts of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the cure characteristics, mechanical and swelling behavior of XNBR/epoxy compounds was experimentally and theoretically investigated. The morphology of the prepared XNBR/epoxy/XHNTs nanocomposites was imaged using scanning electron microscopy (SEM). The effects of various XNBR-grafted nanotubes on the damping factor of nanocomposites were evaluated by dynamic mechanical thermal analysis (DMTA). The cure behavior characterization indicated a fall in the scorch time, but a rise in the cure rate with higher loading of XHNTs into the XNBR/epoxy nanocomposites. SEM micrographs of tensile fracture surfaces were indicative of a rougher fracture surface with a uniform dispersion state of nanotubes into the polymer matrix in the XNBR/epoxy/XHNTs nanocomposites. The stress–strain behavior studies of XNBR/epoxy/XHNTs nanocomposites showed a higher tensile strength up to 40% with 7 wt % XHNTs loading. The theoretical predictions of uniaxial tensile behavior of nanocomposites using Bergström–Boyce model revealed that some of the material parameters were considerably changed with the XHNTs loading. Furthermore, the used theoretical model precisely predicted the nonlinear large strain hyperelastic behavior of nanocomposites

  • Microstructure–Property Relationship of Polyurethane Foams Modified with Baltic Sea Biomass: Microcomputed Tomography vs. Scanning Electron Microscopy
    • Paulina Kosmela
    • Jan Suchorzewski
    • Krzysztof Formela
    • Paweł Kazimierski
    • Józef Haponiuk
    • Łukasz Piszczyk
    2020 Full text Materials

    In this paper, novel rigid polyurethane foams modified with Baltic Sea biomass were compared with traditional petro-based polyurethane foam as reference sample. A special attention was focused on complex studies of microstructure, which was visualized and measured in 3D with high-resolution microcomputed tomography (microCT) and, as commonly applied for this purpose, scanning electron microscopy (SEM). The impact of pore volume, area, shape and orientation on appearance density and thermal insulation properties of polyurethane foams was determined. The results presented in the paper confirm that microcomputed tomography is a useful tool for relatively quick estimation of polyurethane foams’ microstructure, what is crucial especially in the case of thermal insulation materials

  • Microwave-assisted synthesis of a TiO2-CuO heterojunction with enhanced photocatalytic activity against tetracycline
    • Adam Kubiak
    • Zuzanna Bielan
    • Marta Kubacka
    • Elżbieta Gabała
    • Agnieszka Zgoła-Grześkowiak
    • Marcin Janczarek
    • Maciej Zalas
    • Anna Zielińska-Jurek
    • Katarzyna Siwińska-Ciesielczyk
    • Teofil Jesionowski
    2020 Full text APPLIED SURFACE SCIENCE

    A microwave method was used for the synthesis of TiO2-CuO oxide systems. A detailed investigation was made of the effect of the molar ratio of components (TiO2:CuO=9:1, 7:3, 5:5, 3:7, 1:9) on the crystalline structure and morphology. Transmission electron microscopy (TEM) confirmed the presence of octahedral and rod-shaped titania particles and sheet copper(II) oxide particles; moreover, HRTEM analysis indicated the presence of a heterojunction between TiO2 and CuO. The synthesized materials were analyzed by X-ray diffraction (XRD) and Raman spectroscopy, and two crystalline forms (anatase and monoclinic CuO) were detected. The key element of the work was to determine the photocatalytic activity of the obtained binary oxide systems in the degradation of tetracycline. Photo-oxidation tests proved that the binary oxide materials (especially the (9)TiO2-(1)CuO and (7)TiO2-(3)CuO samples) demonstrate high photocatalytic activity in the decomposition of tetracycline (95% after 90 min irradiation) compared with the reference titania samples. Furthermore, a Z-scheme heterojunction photocatalytic process mechanism was proposed. Another important part of the work was the determination of tetracycline photodegradation products using the HPLC/MS technique

  • Między klasyką a awangardą. Szpital Morski na Oksywiu projektu Mariana Lalewicza
    • Weronika Szerle
    2020 Studia Historica Gedanensia

    Celem artykułu jest ukazanie architektonicznego dziedzictwa Szpitala Morskiego w Gdyni, będącego inwestycją wojskową z początku lat 30. XX weku, a powstałego w biurze ważnego i cenionego architekta – Mariana Lalewicza. Ten zasłużony projektant, reprezentant klasycyzmu akademickiego, miał w swym dorobku m.in. kilka gdyńskich obiektów istotnych dla Polskiej Marynarki Wojennej. W 1930 r. podjął się wyzwania szczególnego, jakim była budowa szpitala wojskowego o szerokim spektrum działalności. Miał on być odpowiedzią na zapotrzebowanie rosnącej kadry i jej rodzin, równocześnie stanowiąc zabezpieczenie dla portu wojennego. Projekt, zrealizowany jako pierwszy nowoczesny budynek szpitalny w rozwijającym się mieście portowym, był modernistyczny i niezwykle funkcjonalny. Prezentowano go na opiniotwórczej, ogólnopolskiej wystawie oraz w czasopismach branżowych, gdyż wypełniał najważniejsze podówczas postulaty z zakresu budowy i wyposażenia szpitali, uwzględniając wpływ przyrody na leczenie i poprawę komfortu pacjentów. Szpital zasadniczo mieścił oddziały chirurgiczny i chorób wewnętrznych, miał przy tym pododdziały zakaźny. Działały w nim również przychodnia stomatologiczna, być może też weneryczna, sala operacyjna, rentgen, gabinet fizykoterapii, laboratorium, apteka, prosektorium i kostnica. Z parteru budynku był dobry dostęp na taras, a także na werandy, które powtórzono na pierwszym piętrze. Wyjątkowe były też loggie na dwóch kondygnacjach. Dobre usytuowanie szpitala – na zboczu wzgórza, duże nasłonecznienie i świeże, morskie powietrze były elementami procesów leczenia i rekonwalescencji. Całość obsługiwał personel mieszany – cywilny i wojskowy. W tekście szeroko opisane zostały walory architektoniczne bryły, układu przestrzennego i kompozycji elewacji, w połączeniu z pełnioną funkcją, a przy tym zestawione z podobnymi, europejskimi realizacjami. Uwagę poświęca się również detalowi architektonicznemu, tak w warstwie elewacji, jak i we wnętrzach obiektu, które na skutek remontu w ostatnich kilku latach uległy zniszczeniu. Otwarty wiosną 1932 r obiekt pełnił swą funkcję do wybuchu II wojny światowej, do dziś pozostaje placówką medyczną – aktualnie przychodnią. Jest to dowodem na ponadczasowość projektu i jego układu funkcjonalnego, po niemal 90. latach od jego wykonania.

  • Mikrofiltrowany koncentrat soku brzozowego jako innowacyjny, trwały środek spożywczy o wysokiej wartości odżywczej
    • Maciej Bilek
    • Klaudia Pilch
    • Jarosław Wawer
    • Sosnowski Stanisław
    2020 Medycyna Rodzinna

    Introduction. The forest environment becomes an increasingly popular place of obtaining raw materials, and one of the most promising product is birch sap. The market for bottled birch sap in Poland is monotonous, relying exclusively on pasteurized, acidified and sweetened drinks. A chance to change this situation is to develop a birch sap concentrate obtained by reverse osmosis. It has a sweet taste desired by consumers and particularly high content of minerals, unfortunately it has short shelf life. Aim. The purpose of this work was to develop an effective method of extending the shelf life of birch sap concentrate without the need for pasteurization and chemical interference in the composition. In this way, the new product will be formulated with the potential to compete effectively with synthetic dietary supplements. Material and methods. Birch sap was obtained using drilling technique and continuous collection from the trunks of birch trees (Betula pendula Roth.). The sap was concentrated using reverse osmosis apparatus of our construction, obtaining a sugar concentration, expressed by Brix refractometric extract, equal 2.6° and a dry weight of 2.557%. Microfiltration of birch sap concentrate was carried out under sterile conditions using 0.22, 0.45 and 0.8 μm filters. In the monthly storage test, the measurements were carried out every three days, the optical density parameter was determined. Results. The microfiltration of birch sap concentrate was effective only when 0.22 and 0.45 μm filters were used, no turbidity was observed in the monthly storage test. The samples filtered with a filters with pore diameter of 0.8 μm, became cloudy at analogues time of the test as the samples of non-microfiltered birch sap concentrate, but the turbidity was lowered. Conclusions. The microfiltered birch sap concentrate is characterized by extended shelf life without the addition of chemical substances and without the use of pasteurization process, as well as improved taste compared to the initial raw material without the addition of sweeteners. Thanks to the combination of reverse osmosis and microfiltration, the natural character of the sap is largely preserved. The obtained product has a chance to appear on the food market as an innovative foodstuff. Moreover, due to the high concentration of ions (e.g. zinc and manganese) the concentrate could become an interesting alternative to artificial supplements.

  • Miniaturization of ESPAR Antenna Using Low-Cost 3D Printing Process
    • Mateusz Czeleń
    • Mateusz Rzymowski
    • Krzysztof Nyka
    • Łukasz Kulas
    2020 Full text

    In this paper, the miniaturized electronically steerable parasitic array radiator (ESPAR) antenna is presented. The size reduction was obtained by embedding its active and passive elements in polylactic acid (PLA) plastic material commonly used in low-cost 3D printing. The influence of 3D printing process imperfections on the ESPAR antenna design is investigated and a simple yet effective method to compensate them has been proposed. An antenna prototype was fabricated and measured, which showed that the experimental and simulated results are in good agreement. Realized antenna is characterized by 5.6 dBi peak gain and reflection coefficient of -17.6 dB. Base radius reduction of 23% and occupied area reduction of 40% were achieved.

  • Minimalizacja błędu estymaty położenia obiektu przez redukcję błędów radiowych pomiarów odległości
    • Olga Błaszkiewicz
    • Krzysztof Cwalina
    • Alicja Olejniczak
    • Piotr Rajchowski
    • Jarosław Sadowski
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Utrzymująca się popularność modułu radiowego DWM1000 firmy DecaWave do zastosowań lokalizacyjnych przyczyniła się do przeprowadzenia analizy wpływu błędów radiowych pomiarów odległości na dokładność estymaty położenia lokalizowanego obiektu. W badaniach skupiono się na analizie błędów radiowych pomiarów odległości dla węzłów oddalonych od siebie w zakresie od kilkudziesięciu centymetrów do dziesięciu metrów. Ze względu na błąd rzędu dziesiątek centymetrów dla bliskich odległości pomiędzy węzłami, tj. 0,5 m – 4 m, zaproponowano nieliniowy model korekty błędów zależny wyłącznie od wartości radiowych pomiarów odległości i porównano go z modelem korekty zaproponowanym przez firmę DecaWave. Model korekty opracowano na podstawie pomiarów przeprowadzonych w środowisku wewnątrzbudynkowym.

  • Minimising the Churn Out of the Service by Using a Fairness Mechanism
    • Izabela Mazur
    • Jacek Rak
    • Krzysztof Nowicki
    2020

    The paper proposes an algorithm of bandwidth distribution, ensuring fairness to end-users in computer networks. The proposed algorithm divides users into satisfied and unsatisfied users. It provides fairness in terms of quality of experience (QoE) for satisfied users and quality of service (QoS) for unsatisfied users. In this paper, we present detailed comparisons relevant to service providers to show the advantages of the proposed algorithm over the popular max-min algorithm. Our algorithm is designed to provide service providers with a mechanism to minimize the number of end-user terminations of service, which is one of the most desired factors for service providers.

  • Minute and diverse in fossil sticky stuff: Tanytarsini (Diptera: Chironomidae) from early Eocene Indian Cambay amber
    • Marta Zakrzewska
    • Hukam Singh
    • Ewa Wagner-Wysiecka
    • Wojciech Giłka
    2020 Full text ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

    We here present a pioneering systematic review of fossil dipterans of the tribe Tanytarsini (family Chironomidae) discovered in Indian amber from Cambay. The specimens examined belong to five species: Gujaratomyia miripes, Stempellina stebneri sp. nov., Stempellinella pollex sp. nov., Tanytarsus forfex sp. nov. and Tanytarsus ramus sp. nov., which are described. All species belong to the oldest known Tanytarsini and come from the Cambay shale formation in Tadkeshwar, dated to the early Eocene (~54 Mya). Displaying unusual characters/structures of diagnostic and phylogenetic importance, the specimens studied are discussed against the background of the evolution and systematics of the oldest fossil (Eocene) and extant representatives in the tribe. An updated checklist and key to the identification of genera and species of Tanytarsini from Eocene amber is also provided. The spectral characteristics and physical properties of Cambay amber are similar to those of glessite resins, which are discussed in detail in order to substantiate the identity of the amber and the origin of the inclusions studied.

  • Mitigation of Fake Data Content Poisoning Attacks in NDN via Blockchain
    • Stanisław Barański
    • Jerzy Konorski
    2020

    Abstract—Information-centric networks struggle with content poisoning attacks (CPAs), especially their stronger form called Fake Data CPA, in which an intruder publisher uploads content signed with stolen credentials. Following an existing graphinfection based approach leveraging the constrained time when stolen credentials are useful, we design a blockchain-based mitigation scheme for Named Data Networking architectures. We postulate Proof-of-Time verification to distinguish between intruder and legitimate publishers, and argue that blockchain solutions can implement it natively. The proposed scheme, using the Federated Byzantine Agreement protocol, is described in detail and found to be a valuable alternative to the graph infection approach, superior with respect to outcome determinism, resiliency, and fault tolerance.

  • Mitigation of the Flow Maldistribution in Minichannel and Minigap Heat Exchangers by Introducing Threshold in the Manifolds
    • Paweł Dąbrowski
    2020 Full text Journal of Applied Fluid Mechanics

    In the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel rectangular cross-section (1 mm depth and 1 mm width) minichannels and minigap section (1 mm depth and 99 mm width) with rectangular/trapezoidal manifolds in Z-type flow configuration. The author carried out numerical investigation with various mass flowrates, namely 0.05 kg/s, 0.1 kg/s and 0.2 kg/s which results in Reynolds number of 1532, 3064, 6128 respectively. A novel approach for the mitigation of non-uniform flow has been proposed introducing threshold at the entrance of the minigeometry section. The conventional case without threshold (as reference) and 1 mm, 3 mm and 7 mm threshold were introduced. The threshold has been employed by making a manifolds’ depth bigger than section’s depth. The maldistribution coefficient can be reduced twice in minigap section or three times in the minichannel section already with the 1 mm threshold as compared to the arrangement without threshold. It is found that rectangular manifold gives lower maldistribution coefficient than trapezoidal manifold which corresponds with actual state of the art. The distribution is more uniform in minichannel section than in minigap section for the same inlet parameters. To obtain uniform distribution of fluid flow should be stabilized already at the inlet manifold, at the entrance to the minichannel or minigap section. That was done by introducing the threshold in the manifolds, which is novelty of this study.

  • MnxCo3-xO4 spinel oxides as efficient oxygen evolution reaction catalysts in alkaline media
    • Krystian Lankauf
    • Karolina Cysewska
    • Jakub Karczewski
    • Aleksandra Mielewczyk-Gryń
    • Karolina Górnicka
    • Grzegorz Cempura
    • Ming Chen
    • Piotr Jasiński
    • Sebastian Molin
    2020 Full text INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    The design of efficient electrocatalysts for oxygen evolution reaction (OER) is an essential task in developing sustainable water splitting technology for the production of hydrogen. In this work, manganese cobalt spinel oxides with a general formula of MnxCo3-xO4 (x=0, 0.5, 1, 1.5, 2) were synthesised via a soft chemistry method. Non-equilibrium mixed powder compositions were produced, resulting in high electrocatalytic activity. The oxygen evolution reaction was evaluated in an alkaline medium (1 M KOH). It was shown that the addition of Mn (up to x ≤ 1) to the cubic Co3O4 phase results in an increase of the electrocatalytic performance. The lowest overpotential was obtained for the composition designated as MnCo2O4, which exhibited a dual-phase structure (~30% Co3O4 + 70% Mn1.4Co1.6O4): the benchmark current density of 10 mA cm-2 was achieved at the relatively low overpotential of 327 mV. The corresponding Tafel slope was determined to be ~79 mV dec-1. Stabilities of the electrodes were tested for 25 hours, showing degradation of the MnCo2O4 powder, but no degradation, or even a slight activation for other spinels.

  • Mobile chromatographs and spectrometers for the analysis of chemical warfare agents
    • Waldemar Wardencki
    • Zygfryd Witkiewicz
    • Sławomir Neffe
    2020 Full text

    This article describes the technological state of readiness regarding mobile chromatographs and spectrometers and their appiicability for the analysis of chemical warfare agents (CWAs), degradation products, simulants, and precursors.

  • Mobile Cloud computing architecture for massively parallelizablegeometric computation
    • Víctor Sánchez Ribes
    • Higinio Mora-Mora
    • Andrzej Sobecki
    • Francisco José Mora Gimeno
    2020 Full text COMPUTERS IN INDUSTRY

    Cloud Computing is one of the most disruptive technologies of this century. This technology has been widely adopted in many areas of the society. In the field of manufacturing industry, it can be used to provide advantages in the execution of the complex geometric computation algorithms involved on CAD/CAM processes. The idea proposed in this research consists in outsourcing part of the load to be com- puted in the client machines to the cloud through the Mobile Cloud Computing paradigm. This practice gives substantial benefits to both the clients and the software-provider in terms of costs, flexibility, ubiq- uity and performance. In this document, an outsourcing architecture is proposed based on this paradigm. Extensive experiments have been done using highly parallelizable computational geometry operations to show the strengths and weaknesses of the proposal in combination of specialized computing plat- forms in the cloud. The results suggest that there are some issues that affect the overall performance and the stability of the QoS: the network communication delay, and the number of simultaneous clients and multiple requests. Some solutions have been proposed to face these challenges.

  • Mobile Security: Threats and Best Practices
    • Paweł Weichbroth
    • Łukasz Łysik
    2020 Full text Mobile Information Systems

    Communicating mobile security threats and best practices has become a central objective due to the ongoing discovery of new vulnerabilities of mobile devices. To cope with this overarching issue, the goal of this paper is to identify and analyze existing threats and best practices in the domain of mobile security. To this extent, we conducted a literature review based on a set of keywords. The obtained results concern recognizable threats and established best practices in the domain of mobile security. Afterwards, this outcome was put forward for consideration by mobile application users (n = 167) via a survey instrument. To this end, the results show high awareness of the threats and their countermeasures in the domain of mobile applications. While recognizing the risks associated with physical and social factors, the majority of respondents declared the use of built-in methods to mitigate the negative impact of malicious software and social-engineering scams. The study results contribute to the theory on mobile security through the identification and exploration of a variety of issues, regarding both threats and best practices. Besides this, this bulk of up-to-date knowledge has practical value which reflects in its applicability at both the individual and enterprise level. Moreover, at this point, we argue that understanding the factors affecting users’ intentions and motivations to accept and use particular technologies is crucial to leverage the security of mobile applications. Therefore, future work will cover identifying and modeling users’ perceptions of the security and usability of mobile applications.

  • Model funkcjonalny wpływu czynników na jakość produktu w branży piekarniczej
    • Radosław Drozd
    2020 Aparatura Badawcza i Dydaktyczna

    W artykule zostały przedstawione czynniki, które mają wpływ na jakość produktu w branży piekarniczej. Tym produktem jest pieczywo, a w szczególności chleb, który stanowi od 80% do 90% jego ogólnej produkcji. Autor wyodrębnił czynniki wpływające na jakość produktu i usystematyzował je, a następnie opisał. Podzielone one zostały na 3 grupy funkcjonujące w procesie produkcyjnym, a następnie na podgrupy. Podstawowe grupy czynników, które mają wpływ na jakość produktu to: czynniki surowcowe, czynniki technologiczne i czynniki organizacyjno-techniczne. Podsumowaniem całości opracowania jest opisowy model funkcjonalny wpływu czynników na jakość produktu w branży piekarniczej.

  • Model of aeration system at biological wastewater treatment plant for control design purposes
    • Robert Piotrowski
    • Tomasz Ujazdowski
    2020 Full text

    The wastewater treatment plant (WWTP) is a dynamic, very complex system, in which the most important control parameter is the dissolved oxygen (DO) con-centration. The air is supplied to biological WWTP by the aeration system. Aera-tion is an important and expensive activity in WWTP. The aeration of sewage ful-fils a twofold role. Firstly, oxygen is provided as the main component for biolog-ical processes. Secondly, it supports mixing the sludge with the delivered sew-age, which helps to treat the sewage. The paper proposes a model of the aeration system for biological WWTP located in Northeast Poland. This aeration system consists of the blowers, the main collector pipeline, three lines of the aeration with different diameters and lengths and diffusers. This system is a nonlinear dy-namic system with faster dynamics compared to the internal dynamics of the DO at the biological WWTP. Control of the aeration system is also difficult in terms of control of the DO. A practical approach to model identification and validation is proposed. Simulation tests for aeration system at Matowskie Pastwiska WWTP are presented.

  • Model of Nutrient and Pesticide Outflow with Surface Water to Puck Bay (Southern Baltic Sea)
    • Dominika Kalinowska
    • Paweł Wielgat
    • Tomasz Kolerski
    • Piotr Zima
    2020 Full text Water

    Coastal basins are particularly exposed to the adverse impact of anthropogenic stress. In many places, despite only the seasonal increase in the number of residents, progressive urbanization and associated changes in the catchment characteristics are noticeable. Puck Bay is part of the Gulf of Gdansk and belongs to the Baltic Sea. Although the area of Puck Bay is covered by the Natura 2000 Network, this has not saved it from eutrophication problems. As part of the work on a complex coastal basin analysis (WaterPUCK project), the Soil and Water Assessment Tool (SWAT) model was used to determine the agricultural impact on water quality in rivers with a flow into Puck Bay: Reda, Gizdepka, Płutnica, and Bł ˛adzikowski Stream. The results include the loads of nutrients and pesticides that flow out from the agricultural areas of Puck community into Puck Bay. In this article, special attention has been paid to the impact of precipitation on the quality of water at the outflow of rivers into the Bay of Puck, because it is a decisive element in the amount of nutrients leached along with surface runoff to watercourses and then into the Gulf. The distribution of precipitation thus affects the amount of nutrients absorbed by plants. Modeling the effects of agricultural practices, taking into account long-term meteorological forecasts, is helpful in attempts to reduce the amount of pollutants entering the Baltic Sea.

  • Model systemu zarządzania usługami według metodologii design-thinking
    • Malwina Studzińska
    2020 Full text

    W literaturze przedmiotu brakuje jednoznacznych wskazań odnośnie decyzji o wyborze najbardziej odpowiedniego modelu projektowania usług, szczególnie w kontekście różnych uwarunkowań dla poszczególnych sektorów rynku. Opracowany algorytm umożliwia samodzielne rozwiązanie problemu doboru modelu wewnątrz organizacji, bez konieczności zatrudniania zewnętrznego specjalisty. Algorytm skierowany jest do organizacji w fazie przygotowawczej do projektowania usługi design-thinking. Realizacja zaproponowanych w ramach niego instrukcji zgodnie z określonymi parametrami, zakończy się skierowaniem do najbardziej optymalnego spośród licznych dostępnych modeli, który pozwoli uzyskać usługę uwzględniającą indywidualne uwarunkowania organizacji. Kolejne kroki algorytmu polegają na rozwiązywaniu powstałych sytuacji decyzyjnych, m.in. w zakresie wskazania i hierarchizacji determinant jakości uwzględniających specyfikę sektora danej firmy czy wyboru globalnego celu określającego oczekiwaną usługę. Synteza dużej ilości danych posiadanych przez organizacje w narzędzie o charakterze decyzyjnym była możliwa dzięki zastosowaniu procedury analizy systemowej. Logika rozmyta została wybrana jako podejście metodyczne do analizy porównawczej próby bardzo podobnych do siebie modeli design-thinking. Zastosowanie algorytmu generuje liczne korzyści ekonomiczne, w tym efektywne wykorzystanie zasobów ludzkich firmy.

  • Model zaangażowania w relacji usługodawca-klient
    • Sławomir Ostrowski
    2020

    W niniejszej monografii przedstawiono rozwiązania pozwalające lepiej zrozumieć złożoność relacji występujących pomiędzy usługodawcami a klientami oraz metody, które pozwalają tę wiedzę wykorzystać w doskonaleniu procesów organizacji usługowych. Monografia podejmuje problem kształtowania zaangażowania na styku usługodawca–klient jako wstępnego i koniecznego warunku rozwijania relacji w usługach. Opierając się na klasycznej drabinie lojalności klienta, autor opracował pięciowarstwowy model rozwoju wzajemnego zaangażowania usługodawca–klient oraz poddał ten model badaniom, wykorzystując dane pozyskane ze studiów przypadków. Zaproponowany model zaangażowania autor opisuje w monografii łącznie z mechanizmem kształtowania wzajemnego zaangażowania w relacji usługodawca–klient, który wpływa na możliwość budowy i rozwijania wzajemnych relacji, opartych na wymianie pomiędzy usługodawcą a klientem różnorodnych zapytań, zachęt, komunikatów i wiadomości. Model zawiera 93 czynniki składowe, które wpływają na kształtowanie zaangażowania usługodawca–klient. Model stanowi praktyczne narzędzie badawcze i diagnostyczne, które umożliwia ocenę poziomu zaangażowania po stronie klienta i po stronie usługodawcy oraz analizę czynników składowych zaangażowania, zwłaszcza powiązanych z zaobserwowanymi przeszkodami w procesie komunikacji realizowanym z wykorzystaniem technologii interaktywnych. W monografii zaprezentowano również, w jaki sposób model wizualizuje wyniki analiz w formie raportów diagnostycznych, które pozwalają diagnozować przeszkody w rozwoju zaangażowania i relacji usługodawca–klient.Praktyczne wykorzystanie modelu umożliwia menedżerom wyższego szczebla, kierownikom projektu, specjalistom w projektowaniu oraz udoskonalaniu usług: - ocenę i analizę czynników składowych zaangażowania; - wizualizację wyników analizy w formie raportów diagnostycznych; - podejmowanie działań niezbędnych do usunięcia przeszkód we wskazanych obszarach/czynnikach i podniesienia zaangażowania na wyższy poziom w celu wzmocnienia mechanizmu rozwoju relacji usługodawca–klient. Model zaangażowania w praktycznym zastosowaniu może być pomocnym narzędziem wypełniającym lukę aplikacyjną w zakresie diagnozowania barier w rozwoju zaangażowania i relacji usługodawca–klient, szczególnie w sytuacjach, gdy usługodawca jest zainteresowany pozyskaniem zaangażowania klientów do współudziału w doskonaleniu usług, realizowanym zgodnie z podejściem współprojektowania w ramach modelu otwartych innowacji.

  • Modele ruchu w nowoczesnym zarządzaniu transportem drogowym
    • Jacek Oskarbski
    2020 Full text Transport Miejski i Regionalny

    Wdrożenie i rozwijanie wielopoziomowego modelu podróży i sieci transportowej (MST), w ramach Systemu Planowania Ruchu (SPR), usprawniającego zarządzanie transportem w systemach transportowych z wykorzystaniem usług oferowanych przez Inteligentne Systemy Transportu, może stanowić wsparcie naukowe dla krajowych, regionalnych lub lokalnych administracyjnych jednostek planistycznych i operacyjnych w usprawnieniu systemowego zarządzania ruchem drogowym, w działaniach zmierzających do poprawy poziomu sprawności i bezpieczeństwa w transporcie. W artykule przedstawiono koncepcję, realizację oraz przykłady zastosowań SPR wraz z MST jako kluczowych elementów systemów zarządzania transportem. Zostały one wdrożone w wyniku badań naukowych nad integracją modeli podróży, ruchu i sieci transportowej w ramach realizacji Zintegrowanego Systemu Zarządzania Ruchem TRISTAR w Trójmieście oraz projektów badawczych CIVITAS DYN@MO „DYNamic citizens @ctive for sustainable Mobility”, FLOW „Furthering Less Congestion by Creating Opportunities For More Walking and Cycling” i RID-4D „Wpływ stosowania usług Inteligentnych Systemów Transportowych na poziom bezpieczeństwa ruchu drogowego”.

  • Modele rurociągowych procesów przepływowych
    • Zdzisław Kowalczuk
    • Marek Tatara
    2020

    W rozdziale analizowane jest zagadnienie modelowania oraz parametryzacji procesu przepływu w rurociągach przemysłowych. W pierwszej kolejności przedstawia się bazowy model dyskretny, do którego odnoszone są pozostałe syntezowane rozwiązania. Następnie proponuje się metodę aproksymacji diagonalnej (AMDA), w której stosuje się przybliżenia trójdiagonalnych podmacierzy macierzy rekombinacji za pomocą ich diagonalnych odpowiedników -- co pozwala na zdeterminowanie jawnej formuły na odwrotność tej macierzy. Kolejną propozycję stanowi model Thomasa (ATM), w której dokonuje się przeformułowania modelu bazowego do postaci, względem której można zastosować algorytm Thomasa oraz osiągnąć złożoność obliczeniową O(N). Czwartą propozycję stanowi analityczny model AMSS charakteryzujący stan ustalony (po zaniku procesów przejściowych). W dalszej części opisuje się taki sposób parametryzacji modeli dyskretnych w czasie i przestrzeni, który zapewnia maksymalny zapas stabilności numerycznej syntezowanego modelu, co zweryfikowano symulacyjnie. Na koniec porównano opracowane modele biorąc pod uwagę ich dokładność i czas obliczeń względem wzorcowego modelu bazowego.

  • Modeling of a Quasi-Resonant DC Link Inverter Dedicated to Common-Mode Voltage and Ground Current Reduction
    • Marek Turzyński
    • Michal Frivaldsky
    2020 Full text ENERGIES

    In this paper, the modeling methodology of the AC drive system with a Parallel Quasi-Resonant DC Link Inverter (PQRDCLI) is described. A presented modeling approach is an attractive tool used for the effective evaluation of a common-mode (CM) voltage and grounds current reduction methods. Designed models of inverter, induction machine (IM), and cable are simple, thus the methods for parameter extraction are not complicated. Verification of the proposed modeling approach was realized with the use of the the Synopsys (Mountain View, CA, USA) SABER simulator, while simulation results were experimentally verified. Operation principles of the proposed PQRDCLI converter topology are also described. Based on simulation and experimental results, it was confirmed that the proposed PQRDCLI solution represents required performance within the reduction of common-mode voltage and ground current in electric drives. Moreover, comparisons from a simulation complexity point of view have been performed to the existing methods. The evaluation is being shown at the end of the paper. It is confirmed that the presented method is simple, fast, accurate, and robust as well.

  • Modeling of wood frame structures with different insulation materials under damaging dynamic loading
    • Marcin Szczepański
    • Wojciech Migda
    • Robert Jankowski
    2020 AIP Conference Proceedings

    Wood frame buildings are very popular in regions that are exposed to different dynamic excitations, such as damaging earthquakes. Their seismic resistance is really important in order to prevent structural damages and human losses. This paper presents the results of advanced numerical investigation carried out using the FEM. Based on the models of wall panels, the numerical model of real structure of the wood frame building has been proposed for two cases of thermal insulation (using polyurethane foam and mineral wool). Then, the modal analysis for both models has been conducted so as to compare the frequencies of natural vibrations. Finally, the linear and nonlinear dynamic analyses have been carried out so as to investigate the structural behavior under damaging earthquake excitation. The results of the numerical investigation clearly confirm the beneficial effect of using polyurethane foam as thermal insulation. This can be seen both in the results of modal analysis (higher natural frequencies of building) and seismic analyses, which resulted in a significant reduction in peak values of displacements and accelerations, as compared to the case when mineral wool is applied. Moreover, the results of investigation confirm that the use of the FEM with detailed representation of material and geometric structural properties together with the Newmark algorithm can be considered as the effective approach so as to obtain the accurate response of wood frame building under dynamic loading.

  • Modeling process of planning finished product sales volumes at industrial enterprises in modern economic conditions
    • Kateryna Udachyna
    • Larysa Savchuk
    • Nina Rizun
    2020 Full text Przedsiębiorstwo we współczesnej gospodarce - teoria i praktyka

    This article presents improving the existing system of planning finished products sales volumes. The influencing factors of the sales volumes in modern economic conditions have been determined: falling world oil prices, the reduction of pipe consumption in the domestic market, the global pandemic. The algorithm of planning finished products sales volumes has been constructed. Calculations based on the Holt forecasting method has been done, which allows to make forecast with trend. Calculations based on real data have been conducted, the model has been adapted to modern pandemic conditions, and impact factors have been identified. The plan of finished products sales volumes with factors of influence has been made. Forecast results obtained have been corrected and presented on periods and on markets. System of planning finished product sales volumes at industrial enterprises in modern economic conditions has been improved.

  • Modeling, simulation, and validation of a TB41 crash test of the H2/W5/B concrete vehicle restraint system
    • Łukasz Pachocki
    • Dawid Bruski
    2020 Full text Archives of Civil and Mechanical Engineering

    The paper addresses numerical simulations of a concrete vehicle restraint system. The model is described in detail. The advanced material law of the continuous surface cap model was used to analyze the damage locations in concrete barrier segments. The results were validated against the TB41 full-scale crash test. The test was conducted in compliance with European standard EN 1317, and the validation was performed in accordance with the PD CEN/TR 16303 technical report. The force and moment envelopes of the road safety barrier during a vehicle crash are provided. The detailed concrete segment model successfully reproduced the characteristic splitting failure cracks that were found near the connection of the adjacent barrier segments in the actual structure after the full-scale crash test.

  • Modelling of Abdominal Wall Under Uncertainty of Material Properties
    • Katarzyna Szepietowska
    • Izabela Lubowiecka
    • Benoit Magnain
    • Eric Florentin
    2020 Full text

    The paper concerns abdominal wall modelling. The accurate prediction and simulation of abdominal wall mechanics are important in the context of optimization of ventral hernia repair. The shell Finite Element model is considered, as the one which can be used in patient-specific approach due to relatively easy geometry generation. However, there are uncertainties in this issue, e.g. related to mechanical properties since the properties may vary naturally or as an effect of identification accuracy etc. The aim of the study is to include uncertainties in the modelling and investigate their influence on the model response. The parameters of Gasser-Ogden-Holzapfel hyperelasticmaterialmodel including fibre orientation are treated here as random variables. The uncertainties are propagated with the use of regression based polynomial chaos expansion method. Sobol’ indices are used as the measures of global sensitivity analysis and they provide information about the influence of input uncertainties on the uncertainty of the model output. Uncertainty of parameter affecting stiffness of ground substance (C10) has the highest contribution to the variation of the displacement of chosen point in the center of the abdominal wall.

  • Modelling of dielectric properties of BiNbO4-based microwave ceramics
    • Dionizy Czekaj
    • Agata Lisińska-Czekaj
    • Barbara Garbarz-Glos
    • Wojciech Bąk
    2020 Full text ARCHIVES OF METALLURGY AND MATERIALS

    In the present paper results of the studies devoted to computer simulations of dielectric response of electroceramics in a frequency domain as well as analysis of the experimental data are given. As an object of investigations BiNbO4-based microwave ceramics was taken. Simulations of the hypothetical impedance response of the ceramic system were performed under assumption of the brick-layer model. A strategy for analysis and modelling of the impedance data for microwave electroceramics was discussed. On the base of the discussed strategy modelling of the dielectric response of BiNbO4 ceramics was performed with the electric equivalent circuit method. The Voigt’s and Maxwell’s circuits were taken as electric models. Parameters of the electric components of the circuits were determined and related to parameters of the ceramic object under study. It was found that fitting quality was good and changed within the range χ2 = 6.78 × 10–4 – 6.77 × 10–5 depending on the model.

  • Modelling of heat and mass transfer through wooden buildings
    • Rachid Méchi
    • Emilia Miszewska
    • Khalifa Slimi
    • Robert Jankowski
    2020 Proceedings of the Institution of Civil Engineers-Engineering and Computational Mechanics

    The aim of this review paper is to examine the most recent available studies dealing with theoretical, numerical and experimental aspects related to modelling of heat and mass transfer through wooden buildings. The main thermophysical, mechanical and hygrometric properties of wood are firstly discussed. Then, the basic governing equations of heat and mass transfer phenomena are presented. A detailed description of the physical problem is also shown. After giving the main results from the comprehensive literature review, the authors propose future possibilities of scientific research studies for a better understanding of the complexity of thermomechanical and optimal designing aspects in wood-based construction.

  • Modelling of heat transfer in supercritical pressure recuperators
    • Dariusz Mikielewicz
    • Jarosław Mikielewicz
    2020 Full text ENERGY

    In the paper presented is analysis of convective flow heat transfer at supercritical pressure in channels of heat exchanger working in the thermodynamic cycle. The modelling is based on the division of the flow into three regions, namely the heavy fluid, a two phase flow consisting of the heavy and light fluids and finally the light fluid flow. Modelling is concentrated on the region of simultaneous flow of two fluids divided into the zones with the light and heavy fluids. These agents are considered with averaged thermophysical properties in each region. The surface separating the two zones with respective fluids is assumed to feature the pseudocritical temperature. The problem is solved using a previously developed theoretical model based on considerations of energy dissipation in the flow. The fundamental hypothesis in the model is the fact that heat transfer is considered as being dependent on two contributions of energy dissipation, one stemming from the shearing pseudo two-phase flow of the heavy and light fluids, whereas the second contribution comes from the energy dissipation due to exchange of mass between the heavy and light fluids. The results of calculations have been compared with some experimental data from literature showing a good consistency.