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Repozytorium publikacji
Politechniki Gdańskiej

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  • Analiza osiadania podpór wiaduktu drogowego posadowionego na palach prefabrykowanych na podstawie obliczeń analitycznych, badań terenowych i monitoringu.
    • Paweł Więcławski
    • Maciej Zieliński
    2021 Pełny tekst Inżynieria Morska i Geotechnika

    Zagadnienie dotyczące fundamentów palowych pracujących w grupie pozostaje wciąż nierozwiązane. Pomimo wielu badań doświadczalnych oraz przeprowadzonych analiz naukowych, trudno w sposób jednoznaczny sformułować i przedstawić metodę obliczeniową, która w pełni odzwierciedla rzeczywiste warunki pracy posadowienia pracującego w grupie. Podstawowymi wartościami, które należy ustalić podczas prac projektowych oraz wykonawczych dla omawianej tematyki to przede wszystkim nośność pali oraz wartości ich osiadania. W niniejszym artykule, przedstawiono analizę osiadań dla podpory oraz przyczółka wiaduktu drogowego nad obwodnicą S7 w ciągu ul. Żuławskiej w Elblągu, posadowionego na prefabrykowanych palach żelbetowych pracujących w grupie. Analiza ma na celu znalezienie zależności pomiędzy ogólnodostępną teorią, obliczeniami analitycznymi, numerycznymi i wreszcie faktycznymi rezultatami otrzymanymi z badań terenowych oraz monitoringu. Rezultaty otrzymane z własnych, niezależnych obliczeń, porównano z wartościami posadowienia wyznaczonymi w projekcie technologicznym.

  • Analiza składu chemicznego osadu z pompy GA-301B instalacji Olefiny II
    • Łukasz Gaweł
    2021

    Zakres ekspertyzy obejmuje analizę składu chemicznego osadu pochodzącego z pompy GA-301B z instalacji Olefiny II

  • Analiza temperatury ekwiwalentnej do projektowania nawierzchni asfaltowych w Polsce z wykorzystaniem metody AASHTO 2004
    • Wioletta Leszczyńska
    • Marek Pszczoła
    2021 Pełny tekst Przegląd Komunikacyjny

    W artykule przedstawiono analizę temperatury ekwiwalentnej obliczanej w oparciu o kryterium spękań zmęczeniowych warstw asfaltowych z metody AASHTO 2004 oraz kryterium deformacji strukturalnych Instytutu Asfaltowego. Do obliczeń przyjęto konstrukcję nawierzchni KR5 oraz wykorzystano dane temperaturowe z 50 stacji meteorologicznych z okresu 30 lat od roku 1989 do roku 2019 włącznie udostępnione przez Instytut Meteorologii i Gospodarki Wodnej. Uwzględniono wpływ zmiennego obciążenia nawierzchni ruchem pojazdów ciężkich zarówno w ciągu doby, jak i w ciągu całego roku. Przedstawiono, jak wartości temperatury ekwiwalentnej zmieniają się na terytorium Polski w zależności od lokalizacji stacji meteorologicznej. Analiza obliczeniowa wykazała zmienność temperatury ekwiwalentnej na terytorium Polski w zakresie od +14,68°C (Suwałki) do +16,99°C (Tarnów). Średnia ważona wartość temperatury ekwiwalentnej dla okresu całego roku wynosi +16,01°C i jest ona wyższa od wartości przyjętej w katalogu typowych konstrukcji podatnych i półsztywnych równej +13°C. W artykule przeprowadzono również ocenę wpływu zmiany wartości temperatury ekwiwalentnej na projektowaną grubość warstw asfaltowych konstrukcji nawierzchni.

  • Analiza używania hulajnóg elektrycznych w miastach w kontekście bezpieczeństwa ruchu drogowego na przykładzie Gdańska
    • Karolina Mering
    • Joanna Wachnicka
    2021 Pełny tekst Transport Miejski i Regionalny

    Tematem artykułu jest analiza wpływu hulajnóg elektrycznych na bezpieczeństwo ruchu drogowego w miastach, ze szczególnym uwzględnieniem Gdańska. W pierwszej części, która jest teoretycznym wprowadzeniem do tematu, przedstawiono – w oparciu o zagraniczne publikacje – na jaką skalę ludzie na całym świecie korzystają z hulajnóg elektrycznych i jakie zagrożenia z tego wynikają. Z powodu braku polskiej literatury w zakresie tego stosunkowo nowego tematu oparto się na artykułach naukowych dotyczących sytuacji w Stanach Zjednoczonych, Nowej Zelandii, Francji oraz Niemiec. W analizie skupiono się głównie na przepisach obowiązujących w poszczególnych krajach, najczęstszych zachowaniach użytkowników, liczby wypadków oraz charakterystyce obrażeń. Kolejna część artykułu poświęcona została analizie skali popularności hulajnóg elektrycznych w Polsce, która – jak wykazano – stale rośnie, dzięki rozwijającym się systemom e-hulajnóg współdzielonych, w największych polskich miastach. Omówiono tu tak- że zagrożenia oraz wypadki spowodowane przez jednoślady. Informacje dotyczące stanu aktualnego zostały zebrane wyłącznie na podstawie doniesień medialnych oraz niepotwierdzonych danych udostępnianych przez firmy wypożyczające. Kolejno opisano badania własne przeprowadzone w celu uzyskania wiarygodnych informacji o stanie bezpieczeństwa użytkowników hulajnóg elektrycznych na sieci ulic Gdańska. W tym celu wykonano trzy niezależne badania: badanie ankietowe przeprowadzone na próbie 203 respondentów, rozmowę z pracownikiem firmy wypożyczającej hulajnogi elektryczne na terenie Trójmiasta oraz badanie poligonowe przeprowadzone na podstawie całodziennych nagrań z dwóch skrzyżowań w Gdańsku. Uzyskane wyniki pozwoliły na zaprezentowanie w ostatniej części koncepcji zmian w trzech obszarach: prawa, zarządzania bezpieczeństwem oraz planowania i projektowania. Zaproponowane zmiany mogłyby znacznie wpłynąć na poprawę bezpieczeństwa użytkowników poruszających się na hulajnogach elektrycznych oraz pozostałych uczestników ruchu

  • Analiza wpływu zachowań niechronionych użytkowników dróg na ich poziom bezpieczeństwa w obrębie przejść dla pieszych bez sygnalizacji świetlnej
    • Sabina Kęsicka
    • Joanna Wachnicka
    2021 Pełny tekst Transport Miejski i Regionalny

    Tematem artykułu jest identyfikacja czynników i zależności oddziaływających na zachowanie uczestników ruchu drogowego w kontekście poziomu bezpieczeństwa w obrębie przejść dla pieszych bez sygnalizacji świetlnej. Stosowanie odpowiednio oznakowanych przejść dla pieszych stanowi podstawowy środek ułatwiający przechodzenie pieszych przez jezdnię. Jednak bezwzględna pewność pieszych i rowerzystów o możliwości przekroczenia jezdni w sposób całkowicie bezpieczny może doprowadzać do występowania konfliktów, których skutkiem są zdarzenia drogowe w obrębie przejść. W przedstawionym artykule przybliżono analizę zachowań niechronionych użytkowników drogi w trzech wybranych lokalizacja oraz identyfikacje problemów występujących w danym obszarze. Następnie przedstawiono możliwe do wprowadzenia koncepcję poprawy bezpieczeństwa w oparciu o przeprowadzone badania zachowań uczestników ruchu.

  • Analiza zależności muzyczno-graficznej okładek albumów z użyciem algorytmów uczących się
    • Aleksandra Dorochowicz
    2021 Pełny tekst

    Celem rozprawy jest analiza zależności muzyczno-graficznej okładek albumów z użyciem algorytmów uczących się. Brane są pod uwagę parametry badanych gatunków muzycznych, zależności pomiędzy gatunkami muzycznymi a typami osobowości, jak również cechy okładek albumów muzycznych i ich korelacje z gatunkami muzycznymi. Opracowana metodologia jest wykorzystana w celu sprawdzenia możliwości automatycznej klasyfikacji gatunku muzycznego na podstawie analizy kompozycji okładki albumu. W części teoretycznej przedstawiono podstawy teoretyczne związane z kompozycją okładek, różne rodzaje teorii dotyczących osobowości, jak również opisano różne gatunki muzyczne i przedstawiono zagadnienia związane z parametryzacją sygnałów muzycznych. Dokonano także przeglądu literatury w kontekście zależności pomiędzy typami osobowości a preferowanymi gatunkami muzycznymi. W części praktycznej zawarto eksperymenty wstępne dotyczące klasyfikacji gatunków muzycznych przy użyciu testów subiektywnych i uczenia maszynowego, a także parametry nagrań muzycznych oraz różnych wykonań. Zbadano również, jak odbierane są okładki przez osoby o różnym typie osobowości oraz jakie kolory są kojarzone z danymi socjotypami. W eksperymencie głównym w pierwszej kolejności zbadano zależność między typem osobowości a preferowanymi gatunkami muzycznymi. Następnie została wykonana analiza statystyczna elementów kompozycji okładek różnych gatunków muzycznych oraz znalezione zostały korelacje między gatunkami muzycznymi a projektami okładek. W końcowym eksperymencie sprawdzono możliwość klasyfikacji okładek albumów muzycznych do odpowiednich gatunków przy użyciu algorytmów uczenia maszynowego.

  • Analiza zrealizowanych systemów komunikacji wizualnych dedykowanych miastom w kontekście identyfikacji wizualnej Miasta Gdańska
    • Piotr Czyż
    • Adam Świerżewski
    2021

    Niniejsze opracowanie to raport z dokonanej analizy zrealizowanych systemów komunikacji wizualnej miast i zbadanie możliwości kształtowania, rozwoju i uspójnienia identyfikacji wizualnej marki miasta Gdańsk. Wyniki analizy mogą służyć Miastu Gdańsk jako materiał referencyjny przy ocenie obecnych opracowań własnych i prowadzeniu bieżącej komunikacji swojego wizerunku ale przede wszystkim służą jako materiał bazowy do profesjonalnej dyskusji nad budowaniem strategii rozwoju systemu komunikacji wizualnej Miasta Gdańska. W opinii autorów, kształtowanie spójnej komunikacji wizualnej zdecydowanie poprawia wizerunek miasta jako marki, w szczególności gdy założenia komunikacji wizualnej odpowiadają jego rzeczywistemu charakterowi. Rozumiemy przez to wzajemną odpowiedniość „ducha” komunikacji wizualnej z „duchem” miasta – jego charakteru, historii i przede wszystkim tożsamości. Niniejsze opracowanie ma dwa cele praktyczne. Celem pierwszym jest przedstawienie zamawiającemu zestawienia możliwych ścieżek rozwoju budowania przyszłej komunikacji wizualnej, które posłużą do budowania jej założeń. Związane jest to przede wszystkim z określeniem stosunku do tradycji heraldycznej i jej wykorzystania, bądź nie, w budowaniu marki Miasta Gdańsk.

  • Analysis of AC/DC/DC Converter Modules for Direct Current Fast-Charging Applications
    • Szymon Piasecki
    • Jaroslaw Zaleski
    • Marek Jasinski
    • Serafin Bachman
    • Marek Turzyński
    2021 Pełny tekst ENERGIES

    The paper is a comprehensive laboratory comparison study of two galvanic isolated solution off-board battery chargers: (1) Si-based cost-effective case, and (2) SiC-bidirectional ready for vehicle to grid concept case. All circuits are modular, and in both cases the DC/DC converter can be replaced according to the end user requirements (the coupled transformer remains the same and is constructed based on 12xC100 cores to avoid additional choke). In the case of single active bridge, an active RCD snubber is proposed to protect against overvoltage above 1kV in the DC_2 circuit. The dual active bridge is equipped with soft-star modulation using a zero vector to reduce in-rush current in case of no-load operation, while the AC/DC grid connected converter remains bidirectional to assure the highest power quality at the point of common coupling. All tests were made with real second-used batteries, which improves environmental, economic and technical feasibility of such systems for prosumers. The total efficiency of both AC/DC/DC converters (>97% in SiC and >94% in Si versions) was investigated in the same laboratory conditions.

  • Analysis of energy efficiency of suburban railway transport network
    • Aleksander Jakubowski
    • Krzysztof Karwowski
    • Andrzej Wilk
    2021 Pełny tekst

    Rising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions as well. Information about energy efficiency of whole system operating under realistic conditions could be helpful for modernization of traction power supply, timetable planning or while ordering new rolling stock. This paper presents approach to analysis of energy efficiency of a suburban rail network, using specialized software developed on Matlab/Simulink basis. For the sake of analysis, simple transport network consisting of three lines was considered. Vehicles, assumed as uniform electric multiple units, operate according to the set schedule, taking into account varying electric drive efficiency and mass dependent on passengers’ number. Vehicles are supplied by four substations with nominal voltage of 3000 V DC, using overhead contact line. Developed model includes calculation of energy losses in power supply, therefore it is possible to determine efficiency of the whole network as a relation of mechanical energy of vehicles movement to electrical energy fed from public power system. Mean useful voltages for vehicles and substations are computed as well. Program structure allows for further expansion, e.g. with optimization algorithms.

  • Analysis of Failure Mechanism in Joints with Positive Eccentricity in CFS Truss
    • Małgorzata Gordziej-Zagórowska
    • Elżbieta Urbańska-Galewska
    • Patryk Deniziak
    2021 Pełny tekst Materials

    The paper presents studies concerning the load-bearing capacity of truss joints with a positive eccentricity resulting from the arrangement of geometric members and the failure mechanisms observed in the joints. Based on the previously conducted experimental study, a numerical model of the tested fragment of the CFS truss with eccentricity in the joint was created and validated. All structural details of the tested truss and the loading method consistent with the experiment were taken into account. The results obtained from a uniaxial tensile tests on a steel samples and results estimated during destructive tests carried out on a full-scale of research model were taken into account in validation of the numerical model. Next, appropriate numerical analyses were carried out and parameters such as the eccentricity size in the joint and the wall thickness of sections (t = 1.0, 1.5 and 4.0 mm) were modified. In the range of the studied wall slenderness from λ > 70 (1.0 mm and 1.5 mm thick), it was confirmed that the resistance of truss joints made from CFS open cross-sections with a positive eccentricity, is greater than the resistance that results from known methods of steel structure dimensioning.

  • Analysis of GNSS, Hydroacoustic and Optoelectronic Data Integration Methods Used in Hydrography
    • Oktawia Lewicka
    • Mariusz Specht
    • Andrzej Stateczny
    • Cezary Specht
    • David Brčić
    • Alen Jugović
    • Szymon Widźgowski
    • Marta Wiśniewska
    2021 Pełny tekst SENSORS

    The integration of geospatial data in hydrography, performed using different measurement systems, involves combining several study results to provide a comprehensive analysis. Each of the hydroacoustic and optoelectronic systems is characterised by a different spatial reference system and the method for technical implementation of the measurement. Therefore, the integration of hydrographic data requires that problems in selected fields of electronics, geodesy and physics (acoustics and optics) be solved. The aim of this review is to present selected fusion methods applying the data derived from Global Navigation Satellite System (GNSS), Real Time Kinematic (RTK) measurements, hydrographic surveys, a photogrammetric pass using unmanned vehicles and Terrestrial Laser Scanning (TLS) and compare their accuracy. An additional goal is the evalution of data integration methods according to the International Hydrographic Organization (IHO) S-44 standard. The publication is supplemented by implementation examples of the integration of geospatial data in the Geographic Information System (GIS). The methods described indicate the lack of a uniform methodology for data fusion due to differences in both the spatial reference systems and the techniques used. However, the integration of hydroacoustic and optoelectronic data allows for high accuracy geospatial data to be obtained. This is confirmed by the methods cited, in which the accuracy of integrated geospatial data was in the order of several centimetres.

  • Analysis of Learning Outcomes in Medical Education with the Use of Fuzzy Logic
    • Jacek Stańdo
    • Magdalena Roszak
    • Iwona Mokwa-Tarnowska
    2021 Pełny tekst Studies in Logic, Grammar and Rhetoric

    The national curricula of the EU member states are structured around learning outcomes, selected according to Bloom’s Taxonomy. The authors of this paper claim that using Bloom’s Taxonomy to phrase learning outcomes in medical education in terms of students’ achievements is difficult and unclear. This paper presents an efficient method of assessing course learning outcomes using Fuzzy Logic.

  • Analysis of the causes and effects of cyclist-pedestrian accidents in biggest Polish cities
    • Marek Bauer
    • Romanika Okraszewska
    • Matthias Richter
    2021 Pełny tekst Archives of Transport

    Traffic incidents between pedestrians and cyclists result in an incomparably smaller number of victims (injured and killed) than accidents between unprotected traffic participants and other vehicles. However, such incidents cannot be underestimated, as in most cases they take place on elements of infrastructure designed for pedestrians and cyclists, and thus negatively affect the sense of safety of users in places where they should not only feel safe but also comfortable. This paper presents an analysis of such traffic incidents, aimed at recognizing the share of pedestrians and cyclists as perpetrators and also victims of accidents. Three research hypotheses were examined: that the type of infrastructure and also light and weather conditions influences the structure of perpetrators and victims, that the proportion of accidents between pedestrians and cyclists caused by pedestrians is increasing, and that the proportion of victims of accidents between pedestrians and cyclists in the pedestrian group is decreasing. Analyses were performed based on the number of traffic incidents involving cyclists and pedestrians in the six largest Polish cities, registered in the Police Accident and Collision Records System. A total of 1,702 incidents involving 1,034 injured and killed people in years 2007-2018 were considered. Each traffic incident was considered individually, taking into account changes in perpetrator and victim proportions depending on the type and purpose of the infrastructure and external conditions, as well as variability of these proportions over subsequent years. The tools of mathematical statistics were used, including – among others - significance tests for independent proportions and Chi-squared test for trend. On the basis of the conducted statistical analyses, all research hypothesis were proved. It also confirmed that although the proportions are changing, there are still much more traffic incidents are caused by cyclists, but more victims are in group of pedestrians. The results of the research confirm the need to take action to develop effective mechanisms of mutual interaction between pedestrians and cyclists. Especially in view of the growing bicycle traffic in Polish cities.

  • Analysis of the construction, assembly and usage of specialized fixtures illustrated with an example of machining a lever
    • Adam Barylski
    2021 Technologia i Automatyzacja Montażu

    The paper presents a method of quantitative assessment of manufacturability of the construction of specialized fixtures used in machining. The assumed, simplified assessment criteria include both the complexity of the construction with respect to time-consumption of manufacturing the components and their assembly, as well as the features of the usage of fixtures. The paper contains a study case connected with variably designed functional hardware for machining a cast-iron lever.

  • Analysis of the Heating Process of Hydraulic Motors during Start-Up in Thermal Shock Conditions
    • Ryszard Jasiński
    2021 Pełny tekst ENERGIES

    Conditions that prevail during harsh winters and hot summers pose a serious challenge for machine designers building devices suitable for operation in extreme weather. It is essential for the designers and the users to define the principles and conditions for the safe operation of machines and devices with hydraulic drive in low ambient temperatures. Bearing in mind the above, the author tested the hydraulic motors in thermal shock conditions (cold motors were fed with a hot working medium). This enterprise required the design and construction of a specialized stand for testing hydraulic motors, including satellite motors, in thermal shock conditions. The stand was equipped with the apparatus and a system for measuring the temperature of the moving parts of the satellite motor. The experimental tests were conducted in the laboratory of the Faculty of Mechanical Engineering and Ship Technology at Gda ´nsk University of Technology. The paper presents the results of tests of a correctly and incorrectly operating satellite motor during start-up in thermal shock conditions. The results concerned the course of oil temperatures, temperatures of heated elements, oil pressures, and the pressure drop in the motor. The influence of the oil pressure drop in the motor on its temperature increase was determined. The distributions of the temperature fields of the heated elements of the satellite motor during start-up in thermal shock conditions were derived by means of computer simulation. The utilization of the distribution of the temperature fields of the motor elements enables the evaluation and analysis of the work of this unit. The conducted tests may determine the conditions for the proper operation of hydraulic motors started in thermal shock conditions.

  • Analysis of the Possibility of Using New Types of Protective Coatings and Abrasion-Resistant Linings under the Operating Conditions of the Spiral Classifier at KGHM Polska Miedź S.A. Ore Concentration Plant
    • Marcin Czekajło
    • Krzysztof Żakowski
    • Stefan Krakowiak
    • Sławomir Kierepa
    2021 Pełny tekst Coatings

    A study was carried out to select the appropriate coatings for corrosion protection of the spiral classifier working at KGHM Polska Miedź S.A. Ore Concentration Plant. The abrasion resistance of selected protective coatings and wear-resistant linings was investigated using a DT-523 rotary abrasion tester with Taber CS-10 rubber abrasive discs. The average weight loss of the coatings after a cycle of 2000 revolutions was determined. Tests of protective coatings using the electrochemical impedance spectroscopy (EIS) technique were carried out to determine the suita-bility of coatings in the highly saline environment of the aqueous suspension of ground copper ore. During the measurements, changes in resistance, polarising current and capacitance were determined as a function of time for the tested coatings. The linings selected on the basis of laboratory tests were also tested under industrial conditions. Their degrees of wear were characterised. The results obtained indicated the highest abrasion resistance of materials from the polyolefin group (polyethylenes), where the average weight loss did not exceed 5 g/dm2. In the case of protective coatings, the highest durability was demonstrated by coatings with additives of ceramic aggregates, phenol-epoxy, and an elastomeric coating based on polyurea, whose average weight loss during the test cycle did not exceed 19 g/dm2. EIS measurements showed that the tested coatings were resistant to the aggressive environment of the feedstock. Tests under cathodic polarisation conditions of the samples at a potential below the protection potential showed that they were resistant to a highly saline environment and were also resistant to its alkalinisation resulting from the application of cathodic protection, which will be used to protect the classifier together with protective coatings. Tests carried out under industrial conditions using wear-resistant linings made of plastics have made it possible to analyse the mechanism and degree of wear of the various materials during the operation of the classifier. Measurements of lining wear were made in relation to baseline volumes. Polyurethane, a polymer lining based on MDI and PTMG, and those made of ultra-high-molecular-weight polyethylene with anti-stick additives showed the lowest wear rates.

  • ANALYSIS OF THE RESULTS OF THE AUDIT OF LIGHTING PARAMETERS AT PEDESTRIAN CROSSINGS IN WARSAW
    • Piotr Tomczuk
    • Marcin Chrzanowicz
    • Tomasz Mackun
    • Marcin Budzyński
    2021 Pełny tekst Archives of Transport

    The night time, based on many world studies, generates an increased risk of serious accidents (with fatalities and serious injuries). This is especially true for accidents with pedestrians. Pedestrian crossings are very sensitive to the influence of the time of day in terms of pedestrian safety, elements of road infrastructure. This is visible on the example of Poland, where numerous accidents at crosswalks are recorded, characterized by high severity at night. Road infrastructure man-agers take corrective actions to improve this condition. An example of such work is the Road Safety Audit (RSA), initiated in 2016 by the Municipal Roads Management Board in Warsaw. The analyses carried out by the authors, among others, in the years 2016 - 2019, included pedestrian crossings without traffic lights located on roads managed by ZDM (Municipal Roads Authority) in twelve districts: Bemowo, Bielany, Mokotów, Ochota, Praga Południe, Praga Północ, Śródmieście, Targówek, Ursynów, Wawer, Włochy, Żoliborz. The assessment was carried out in terms of the correct lighting of these passages, traffic organization, geometry and environmental impact. The main aim of the article is to present a methodology for evaluating the technical condition of road lighting infrastructure on a large scale (e.g. district, city). The article dis-cusses the general and detailed state of pedestrian safety in Poland against the background of research conducted in Warsaw. The procedure of inspection and assessment of the state of lighting of pedestrian crossings is described and selected results are presented. On the basis of a detailed analysis of the results of individual pedestrian crossings, the general condition of the tested crossings was assessed and recommendations were indicated. An attempt was made to assess the influence of pedestrian crossings lighting on the general state of road safety. A critical evaluation of the obtained effects was made. The utilitarian aim of the article is to apply the described methodology in other cities and to use the results of the conducted analyses to plan and implement road investments in the field of modernization of lighting at pe-destrian crossings on a large scale.

  • Analysis of the state of preservation the historic arcaded houses in Vistula Delta listed in the National Inventory of Historical Monuments
    • Tomasz Zybała
    2021 Pełny tekst Budownictwo i Architektura

    Historic arcaded houses are part of the material heritage of the Vistula Delta. Unfortunately, their number is decreasing year by year. The article is the result of a query of available sources and field research carried out by the author in 2015-2020. The paper presents the current state of preservation the historic arcaded houses in Vistula Delta listed in the National Inventory of Historical Monuments. Criteria for the selection of test objects are described. The author has prepared a tabular list of arcaded houses with information about their location, type according to Kloeppel statistics, date of construction, technical condition and functions. The summary of the analysis are pie charts with a statistical presentation of the data collected by the author during the research.

  • Analysis of the Water Level Variation in the Polish Part of the Vistula Lagoon (Baltic Sea) and Estimation of Water Inflow and Outflow Transport through the Strait of Baltiysk in the Years 2008–2017
    • Michał Szydłowski
    • Wojciech Artichowicz
    • Piotr Zima
    2021 Pełny tekst Water

    The Vistula Lagoon is located in both Poland and Russia along the southern coast of the Baltic Sea. It is connected to the Baltic Sea in the Russian part by the Strait of Baltiysk. The purpose of the paper is to identify the dominant factors underlying the water level variation mechanism at Tolkmicko in the Vistula Lagoon, revealed by a statistical analysis of the measured data and a discussion on the inflow and outflow transport variation through the strait, estimated by nu-merical modeling. Seawater transport is exceptionally valuable in terms of the hydrological water balance in the lagoon. Historical research on the hydrology of the lagoon shows that the water exchange in the lagoon is quite complex due to the presence of several different sources of water balance, such as seawater inflow, river inflow, groundwater inflow, precipitation, and evaporation. Unfortunately, there are no current data on seawater inflow and outflow through the Strait of Baltiysk due to the lack of continuous flow measurements in the strait. A novelty of the current work is an in-depth statistical analysis of the water level variation in the Polish part of the lagoon over a long time period and an estimation of water transport through the Strait of Baltiysk by use of a numerical model. The model reproduces well the water level variation re-sponding to variations in the sea level outside the lagoon and the wind action over the lagoon. The years 2008–2017 were chosen as the analysis period. A two-dimensional free surface shallow water numerical model of the lagoon was adapted to simulate the water level variation in view of the wind over the lagoon and the sea level variation at one open boundary. Finally, it was concluded that the water level variation on the Polish side of the Vistula Lagoon is dominated by two factors: the water level in the Gulf of Gdańsk and the wind over the lagoon. The average annual marine water inflow into the Vistula Lagoon was estimated to be equal to 15.87 km3.

  • Analytical approach for membrane action in laterally-restrained reinforced concrete square slabs under uniformly distributed loads
    • Shan Wang
    • Shao-Bo Kang
    • Qiao-Ling Fu
    • Jiaxing Ma
    • Patryk Ziolkowski
    2021 Journal of Building Engineering

    Laterally-restrained reinforced concrete slabs can mobilise compressive membrane action and subsequent tensile membrane action under extreme loading conditions, thereby enhancing the load resistance under uniformly distributed loads. Previous analytical study focuses primarily on tensile membrane action in simply-supported slabs. This paper describes an analytical approach for membrane action in laterally-restrained square slabs. In the model, a yield line pattern is presumed for slabs, and the whole slab is divided into a strip system in the orthogonal directions. Each strip is analysed by establishing compatibility and equilibrium. The model is validated against test data of reinforced concrete square slabs, and reasonably good agreement is obtained in terms of the load capacity. The distributions of membrane force, bending moment and neutral axis depth along yield lines are also obtained through the analytical approach, and propagation of the tension zone from the centre towards the edge of slabs is also demonstrated by using the contour of membrane forces in the slab. Contributions of bending moment and membrane force to the load resistance of slabs are quantified by decomposing the total resistance according to equilibrium. The contribution of each slab strip is also quantified to gain insight on the distribution of resistance in the whole slab. Finally, a design method is proposed to calculate the capacity of compressive membrane action in square slabs.

  • Analytical ‘Steady-State’-Based Derivation and Clarification of the Courant-Friedrichs-Lewy Condition for Pipe Flow
    • Zdzisław Kowalczuk
    • Marek Tatara
    2021 Pełny tekst Journal of Natural Gas Science and Engineering

    This article addresses the problem of choosing the optimal discretization grid for emulating fluid flow through a pipeline. The aggregated basic flow model is linearized near the operating point obtained from the steady state analytic solution of the differential equations under consideration. Based on this model, the relationship between the Courant number (μ) and the stability margin is examined. The numerically set coefficient μ, ensuring the maximum margin of stability, is analyzed in terms of the physical and technological parameters of the flow. As a result of this analysis, a specific formula is obtained based on parameters describing the mechanics (geometry and physics) of the flow through the pipeline, which leads to the optimal value of the Courant number, separately for smooth and rough pumping conditions. A more detailed analysis of the distribution of the optimal μ coefficient in relation to the parameters of the pipeline flow mechanics shows four cases to consider when determining the coefficient μ. Surprisingly, in three cases, the CFL condition is insufficient, which is expressed in the form of the proposed procedure for choosing the optimal value of μ. The final dichotomous model is derived from the Monte Carlo simulation results in which the effect of each parameter on the optimal Courant number is estimated and consolidated. Taking into account the recognized general laws of physics and using numerical methods and mathematical analysis, simple and useful analytical relationships describing the flow process are obtained. In addition, computer simulations are performed to verify the correctness of the proposed procedure, as well as a number of other considerations related to the modeling of fluid flow in transport pipelines.

  • Analytical Strategies and Applications in Lipidomics
    • Weronika Hewelt-Belka
    • Agata Kot-Wasik
    2021

    Lipidomics is a field of study aiming at a comprehensive analysis of a set of lipids in biological systems. This includes both quantitative and qualitative characterization of lipid profiles, comparative studies of lipidomes, and analysis of lipid-protein interactions. Lipids are structurally diversified that make their analysis a challenging task. The constant advances in analytical technologies, especially in the field of high-performance liquid chromatography and mass spectrometry, drive progress in lipid science. Commonly, lipidomics strategies are classified as targeted, untargeted, and focused. Many analytical techniques can be employed in the lipidomic study. The choice of an appropriate analytical tool for lipid analysis depends mainly on the aim of the study. In this chapter, we present an overview of the analytical techniques and data treatment used in the analysis of lipids in biological samples, with a special focus on LC-MS-based approaches. We also present the application of the lipidomic study in the comprehensive comparative analysis and discuss the limitation and advantages of the sample preparation techniques used in lipidomics.

  • Analyzing content of tasks in Business Process Management. Blending task execution and organization perspectives
    • Nina Rizun
    • Aleksandra Revina
    • Vera Meister
    2021 Pełny tekst COMPUTERS IN INDUSTRY

    An efficient organization, management, and execution of tasks are central for the successful functioning of any organization. This topic was on the research agenda already in the early 1950s and keeps attracting the scientific community's attention today. Continuous advances and penetration of technologies in organizations are expected to increase task variety and complexity. This creates a constant demand for new methods to analyze, measure, manage, and execute tasks. In this study, we extract relevant task content aspects from textual task descriptions and build a task content model as a basis for the development of various decision-support solutions for process workers and managers. Using the Theory of Situation Awareness, we specify a method for analyzing and measuring the content of tasks and illustrate it by an industry example of ITIL IT ticket processing. We refer to the Strategic Alignment Model while discussing the implications for task management and execution research and practice.

  • Analyzing Preconditions to Introduce Internet Voting in Portugal: Insights from the Estonian Model
    • Marlon Freire
    • Sérgio Nunes
    • David Duenas Cid
    2021 Pełny tekst

    Internet voting has been trialed or introduced for several countries, including Norway, Portugal, United States, United Kingdom and Switzerland as an additional voting channel to increase voter turnout and, also to modernize the electoral process. However, only Estonia has successful introduced internet voting, deploying e-enabled elections in general governmental levels. This paper aims to provide an exploratory study on the Estonian internet voting model to identify pre-conditions for internet voting introduction in Portugal, addressing legal, technical and technological considerations. For doing so, it includes a cross-country comparative analysis in two perspectives. Firstly, an analysis in the Estonian electoral framework, highlighting the most important legal adaptations that make possible internet voting introduction to identify potential transformation for the Portuguese context. Secondly, to provide a technological overview towards the Portuguese e-government ecosystem to seek similar conditions that can make internet voting possible in Estonia.

  • Ancient settlements-atavistic solutions for present water supply and drainage problems engendered by urbanism
    • Thirumalini Selvaraj
    • Asmita Yadav
    • Haritima Bahuguna
    • Jakub Drewnowski
    • Mahesh Ganesapillai
    2021 ENVIRONMENT DEVELOPMENT AND SUSTAINABILITY

    Water is the most valuable resource available on earth. Although it is present in abundance, its usable volume is very scarce. This is the reason behind the existence of both floods and droughts around the world. However, human settlements face water scarcity issues that are primarily engendered by improper town planning measures. To create a balance between the available fractions of water, it is therefore imperative to have proper water planning and management. Numerous water management techniques in operation in ancient civilizations like the Mohenjo-Daro, Mesopotamian, Roman, and Chinese drainage system have been proven to be more efficient than the contemporary methods and can therefore be used to ameliorate the current scenario. Thus, the objective of this study is to analyze water issues in three developing cities in the Asia Pacific region viz., Chennai, Kathmandu, and Jakarta by identifying the source of the problem and provide potential solutions based on the techniques followed in the ancient civilizations. Moreover, this study also aims to address the common issues in urban water planning and provide suggestions for a better and sustainable system.

  • ANFIS-Based NPC Population Control in Video Games
    • Tomasz Boiński
    2021 Pełny tekst

    Modern computer games aim at providing rich, vivid worlds. The aim is to encourage the player to explore and interact with the in-game world. To describe the complex relations between in-game NPCs and their surrounding fuzzy logic is used. The paper presents ANFIS based population control in the video game. We present an approach allowing stabilizing the number of NPCs in-game by providing a certain amount of food to the environment. The aim of the solution is to emulate a lifelike but stable environment. The system is tasked to react to the player's actions. The paper describes the solution and provides its evaluation.

  • Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020
    • Barbara Kot
    • Agata Grużewska
    • Piotr Szweda
    • Jolanta Wicha
    • Urszula Parulska
    2021 Pełny tekst Antibiotics-Basel

    The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

  • Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
    • Agnieszka Siebert
    • Milena Deptuła
    • Mirosława Cichorek
    • Anna Ronowska
    • Grzegorz Cholewiński
    • Janusz Rachoń
    2021 Pełny tekst Anti-Cancer Agents in Medicinal Chemistry

    Background: Although Mycophenolic Acid (MPA) is applied as prodrugs in clinic as an immunosuppressant, it also possesses anticancer activity. MPA acts as Inosine-5’-Monophosphate Dehydrogenase (IMPDH) inhibitor, where the carboxylic group at the end of the side chain interacts with Ser 276 of the enzyme via hydrogen bonds. Therefore, MPA derivatives with other polar groups indicated high inhibition too. On the other hand, potent anticancer agents like dacarbazine and cisplatin give numerous side-effects. Objective: Based on the literature data, MPA derivatives should be explored towards anticancer properties. Conversion of the carboxylic group of MPA to amide could maintain antiproliferative activity. Therefore, we decided to investigate several amino acid and peptide derivatives of MPA against chosen cancer cell lines in vitro. Methods: Amides of MPA hold threonine and arginine amino acid unit. These amino acid derivatives were tested as L and D enantiomers and both in free acid and methyl esters forms. Additionally, MPA was modified with tuftsin or retro-tuftsin as biologically active peptides, which could act as a drug carrier. Results: Amino acid and peptide derivatives of MPA were investigated in vitro as potential anticancer agents on cell lines: Ab melanoma, A375 melanoma and SHSY5Y neuroblastoma. The activity of the tested compounds was compared to parent MPA and known chemotherapeutics: dacarbazine and cisplatin. Conclusion: Amino acid moiety and the sequence of amino acids in the peptide part influenced observed activity. The most active amino acid MPA analogues occurred to be D and L-threonine derivatives as methyl esters, probably due to better cell membrane penetration.

  • Antifungal Activity of Capridine β as a Consequence of Its Biotransformation into Metabolite Affecting Yeast Topoisomerase II Activity
    • Iwona Gabriel
    • Kamila Rząd
    • Ewa Paluszkiewicz
    • Katarzyna Kozłowska-Tylingo
    2021 Pełny tekst Pathogens

    In the last few years,increasing importance is attached to problems caused by fungal pathogens. Current methods of preventing fungal infections remain unsatisfactory. There are several antifungal compounds whichare highly effective in some cases, however, they have limitations in usage: Nephrotoxicity and other adverse effects. In addition, the frequent use of available fungistatic drugs promotes drug resistance. Therefore, there is an urgent need for the development of a novel antifungal drug with a different mechanism of action, blocking of the fungal DNA topoisomerases activity appear to be a promising idea. According to previous studies on the m-AMSA moderate inhibitory effect on fungal topoisomerase II, we have decided to study Capridine β (also acridine derivative)antifungal activity,as well as its inhibitory potential on yeast topoisomerase II (yTOPOII). Results indicated that Capridineβantifungal activity depends on the kind of strains analyzed (MICs range 0.5–64μgmL−1) and is related to its biotransformation in the cells. An investigation of metabolite formation, identified as Capridine β reduction product (IE1) by the fungus Candida albicanswas performed. IE1 exhibited no activity against fungal cells due to an inability to enter thecells. Although no antifungal activity was observed, in contrast to Capridine β, biotransformation metabolite totally inhibited the yTOPOII-mediated relaxation at concentrations lower than detected for m-AMSA. The closely related Capridine βonly slightly diminished the catalytic activity of yTOPOII.

  • Antiproliferative, Antiangiogenic, and Antimetastatic Therapy Response by Mangiferin in a Syngeneic Immunocompetent Colorectal Cancer Mouse Model Involves Changes in Mitochondrial Energy Metabolism
    • César Julio Rodriguez-Gonzalez
    • Ivones Hernández-Balmaseda
    • Ken Declerck
    • Claudina Pérez-Novo
    • Emilie Logie
    • Claudia Theys
    • Patrycja Jakubek
    • Luisa Olga Quiñones-Maza
    • Geovanni Dantas-Cassali
    • Diego Carlos dos Reis
    • Guy Van Camp
    • Miriam Teresa Lopes Paz
    • Idania Rodeiro-Guerra
    • René Delgado-Hernández
    • Wim Vanden Berghe
    2021 Pełny tekst Frontiers in Pharmacology

    In spite of the current advances and achievements in cancer treatments, colorectal cancer (CRC) persists as one of the most prevalent and deadly tumor types in both men and women worldwide. Drug resistance, adverse side effects and high rate of angiogenesis, metastasis and tumor relapse remain one of the greatest challenges in long-term management of CRC and urges need for new leads of anticancer drugs. We demonstrate that CRC treatment with the phytopharmaceutical mangiferin (MGF), a glucosylxanthone present in Mango tree stem bark and leaves (Mangifera Indica L.), induces dose-dependent tumor regression and decreases lung metastasis in a syngeneic immunocompetent allograft mouse model of murine CT26 colon carcinoma, which increases overall survival of mice. Antimetastatic and antiangiogenic MGF effects could be further validated in a wound healing in vitro model in human HT29 cells and in a matrigel plug implant mouse model. Interestingly, transcriptome pathway enrichment analysis demonstrates that MGF inhibits tumor growth, metastasis and angiogenesis by multitargeting of mitochondrial oxidoreductase and fatty acid β-oxidation metabolism, PPAR, SIRT, NFκB, Stat3, HIF, Wnt and GP6 signaling pathways. MGF effects on fatty acid β-oxidation metabolism and carnitine palmitoyltransferase 1 (CPT1) protein expression could be further confirmed in vitro in human HT29 colon cells. In conclusion, antitumor, antiangiogenic and antimetastatic effects of MGF treatment hold promise to reduce adverse toxicity and to mitigate therapeutic outcome of colorectal cancer treatment by targeting mitochondrial energy metabolism in the tumor microenvironment.

  • Application of advanced spectroscopic methods in the assessment of the leachability degree of hazardous elements from the matrix of cellular concretea
    • Paulina Augustyniak
    • Alicja Saczuk
    • Hubert Byliński
    • Bartłomiej Cieślik
    2021

    Due to its structure, autoclaved cellular concrete exhibits good insulating properties with relatively high compressive strength values. It is increasingly used in construction because of its economic attractiveness. Autoclaved cellular concrete is mainly used in interior structure layers, and therefore its potential exposure to heavy metal leaching from the matrix may be related to the presence of a high pH medium from other materials in the structure. The effectiveness of the immobilization of hazardous substances potentially occurring in the concrete structure depends on many factors, including the charac-teristics of the raw material input and the conditions of material maturation. This study investigated the immobilization level of potentially hazardous substances in cellular concrete available on the Polish market. The leaching of heavy metals from the aforementioned materials, using different media and environments for the exploita-tion of potential future building blocks was also discussed, as well as the possibility of using advanced spectroscopic techniques in this type of study.

  • Application of Artificial Neural Networks to Predict Insulation Properties of Lightweight Concrete
    • Marzena Kurpińska
    • Leszek Kułak
    • Tadeusz Miruszewski
    • Marcin Byczuk
    2021 Pełny tekst Applied Sciences-Basel

    Predicting the properties of concrete before its design and application process allows for refining and optimizing its composition. However, the properties of lightweight concrete are much harder to predict than those of normal weight concrete, especially if the forecast concerns the insulating properties of concrete with artificial lightweight aggregate (LWA). It is possible to use porous aggregates and precisely modify the composition of lightweight concrete (LWC) with specific insulating properties. In this case, it is advisable to determine the parameters of the components and perform preliminary laboratory tests, and then use theoretical methods (e.g., artificial neural networks (ANNs) to predict not only the mechanical properties of lightweight concrete, but also its thermal insulation properties. Fifteen types of lightweight concrete, differing in light filler, were tested. Lightweight aggregates with different grain diameters and lightweight aggregate grains with different porosity were used. For the tests, expanded glass was applied as a filler with very good thermal insulation properties and granulated sintered fly ash, characterized by a relatively low density and high crushing strength in the group of LWAs. The aim of the work is to demonstrate the usefulness of an ANN for the determination of the relationship between the selection of the type and quantity of LWA and porosity, density, compressive strength, and thermal conductivity (TC) of the LWC.

  • Application of chromogenic dye in biogenic amines determination using spectrophotometry
    • Kaja Kalinowska
    • Marek Tobiszewski
    2021 Pełny tekst

    Biogenic amines content can be the source of information in the field of freshness and suitability of certain foods for consumption. However, most analytical methods for their determination require complicated sample preparation and expert knowledge. Because of that, a novel approach based on chromogenic dye application was proposed. After the SN1 reaction of an amine with S 0378 dye, the absorbance of the solution was measured using spectrophotometry. With the proposed methodology, it was possible to determine total biogenic amines content in the range of 0.5–100 μg L–1 with a determination coefficient exceeding 0.98.

  • Application of deep eutectic solvents (DES) in analytical chemistry
    • Aleksandra Kramarz
    • Patrycja Makoś-Chełstowska
    • Justyna Płotka-Wasylka
    2021 Pełny tekst

    Recent years have been associated with efforts to reduce the impact on the natural environment. A greener approach has been introduced in various areas of science, including analytical chemistry. One of the basic procedures for preparing a sample for analysis is its extraction. Traditional methods involve the use of large amounts of organic compounds, often toxic, with an unfavorable impact on the environment. A representative of the “green” approach to the problem of organic solvents are new materials - deep eutectic solvents (DES). They are promising solvents with many advantages (low toxicity, biodegradability, low cost), which are increasingly used in many chemical and technological processes, including the extraction process.

  • Application of deep eutectic solvents for separation and determination of bioactive compounds in medicinal plants
    • Alina Kalyniukova
    • Jaroslav Holuša
    • David Musiolek
    • Jana Sedlakova-Kadukova
    • Justyna Płotka-Wasylka
    • Vasil Andruch
    2021 Pełny tekst INDUSTRIAL CROPS AND PRODUCTS

    The medicinal plants industry, particularly in regard to products rich in biologically active substances for maintaining health, has grown by leaps and bounds in the last decade, with sales of over-the-counter drugs containing these substances growing by billions of dollars. Attention has thus also been paid to the safety and effectiveness of these medicines. We are currently witnessing a rapid increase in the number of publications devoted to the development of new separation procedures that are not only fast and cheap but also more efficient and eco-friendlier, improving both yields and quality of extracts quality without using hazardous organic solvents. The new approaches include those that use deep eutectic solvents (DES), which are characterized by unique parameters. In fact, DESs can be used for both the isolation and determination of biologically active substances in medicinal plants. Therefore, the purpose of the review is to gather details on the application of DESs in the separation of bioactive compounds in medicinal plants and to provide a solid background for future research in this area. To cover these aspects, the available data and references in the field of interest are reviewed and summarized.

  • Application of different building representation techniques in HEC-RAS 2-D for urban flood modeling using the Toce River experimental case
    • Andam Mustafa
    • Michał Szydłowski
    2021 Pełny tekst PeerJ

    This paper presents the impact of the choice of building representation techniques and hydrodynamic models on urban flood simulations using HEC-RAS 2-D for the Toce River physical model. To this end, eight numerical models based on previous laboratory experiments were prepared to simulate unsteady urban flooding on each side of building units. Two simplified building layouts (aligned and staggered) were examined, where models were prepared for two different building representation techniques: Building Block (BB) and Building Resistance (BR). Water depth variation computations using the BR and BB techniques were compared to the laboratory measurements and previous studies in the literature. A statistical analysis was performed using both the Root Mean Square Error (RMSE) and the Pearson Product-Moment Correlation Coefficient (PPMCC) in order to evaluate the performance of the models. A sensitivity analysis showed that the proper mesh resolution and model parameter values were obtained. As far as the BR technique is concerned, it is well-suited for representing building units in numerical simulations using high Manning coefficients. Furthermore, this study confirms the importance of the BR technique, which should help researchers in using low-resolution Digital Elevation Models (DEMs) along with open-source programs. Moreover, the study aims to produce a deeper comprehension of numerical modeling and urban flooding.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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