Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • Application of the 2-deoxyglucose scaffold as a new chiral probe for elucidation of the absolute configuration of secondary alcohols
    • Alicja Trocka
    • Katarzyna Szwarc-Karabyka
    • Sławomir Makowiec
    • Tomasz Laskowski
    2022 Pełny tekst Scientific Reports

    Herein, we present the application of 2-deoxy-D-glucose derivatives as chiral probes for elucidation of the absolute configuration of chiral secondary alcohols. The probes are attached to the studied molecules via glycosylation reaction and the resulting products are examined by a set of standard 2D NMR experiments. The absolute configuration of an oxymethine carbon atom binding the probe is established on a basis of a set of diagnostic dipolar couplings (NOEs/ROEs). These correlations may be considered diagnostic due to a pronounced lack of conformational freedom of the formed glycosidic linkage. While the chance for an observation of the diagnostic signals is the highest when the resulting glycoside in an α-anomer. 2-deoxy-D-glucose was selected as a probe of choice since is it known to strongly prefer the formation of α-glycosides

  • Application of the corrosion tester in corrosion tests using the acoustic emission method.
    • Krzysztof Emilianowicz
    • Milena Supernak
    • Agnieszka Ossowska
    2022 Pełny tekst Polish Maritime Research

    The article presents an innovative method of corrosion tests using the acoustic emission method and the corrosion tester. The problem of corrosion occurring in ballast tanks and tanks carrying petroleum products is discussed. The acoustic method is presented which, due to the use of a unique corrosion tester, is used to monitor the course of corrosion processes in steel. The principle of operation of the corrosion tester, its construction and its use in Non Destructive Testing (NDT) are described in detail. Corrosion test results, obtained with the use of a corrosion tester, are presented. An analysis and a short discussion of the obtained results are given. The results of both the acoustic and metallographic tests prove the possibility of detecting material damage occurring during the operation of the corrosion tester, allowing determination of the course and type of corrosion damage.

  • Application of the ISE Optimized Proportional Control of the Wave Maker in a Towing Tank
    • Marcin Drzewiecki
    • Jarosław Guziński
    2022 Pełny tekst IEEE Access

    This paper presents the improvement of the wave maker control system. The wave maker is a facility widely used in hydromechanics laboratories to generate waves in towing tanks. It is equipped with an electrohydraulic drive and an actuator submerged into water. The waves are generated to model the environmental conditions for physical experiments, performed on reduced-scale models of maritime objects. The physical experiments allow to predict the behaviour of full-scale objects and prove the results of numerical analyses. The overriding goal of the fluid dynamics experiments is to improve the human safety and survivability of constructions. The reported investigation and application works were vital for the improvement of physical model tests. The optimization of the proportional controllers was performed in terms of the Integral of Squared Error (ISE). The final evaluation was performed in terms of the frequency response characteristic. The results of the proportional control optimization were evaluated versus the previously applied control. The experimental research was conducted in the real towing tank located at the Maritime Advanced Research Centre. The investigation has shown the advantage of the ISE optimized conventional proportional control. It has particularly proven the affordability and swiftness of the optimization process. It also proved a more efficient frequency response of the wave maker obtained within a required and reasonable lead time. The performed investigation has greatly contributed to the development of a new method of physical experiments in white noise waves. The results related to this new more efficient method are presented as well.

  • Application of Traction Supply System for Charging Electric Cars
    • Mikołaj Bartłomiejczyk
    • Leszek Jarzębowicz
    • Roman Hrbáč
    2022 Pełny tekst ENERGIES

    The development of electromobility involves the development of electric cars charging infrastructure. The increase of the number of chargers poses new demands for the AC power grid, especially in regard to its capacity of delivering high peak power. As an alternative for the public AC power grid, urban electrified transportation systems (trams, trolleybuses, and metro) can be used for supplying electric cars chargers. The article discusses four options of integrating electric cars chargers with a traction power supply system. The option of connecting the charger to the traction overhead supply line has been selected due to the spatial availability of the power source and possibility to use regenerative braking energy for charging. A set of criteria has been developed for analysing the capability of the traction supply system to feed electric cars chargers. An exemplary feasibility analysis was carried out for trolleybus traction supply system in Gdynia, Poland. The impact of installing the charging station on specific traction supply parameters has been predicted using present-state recordings of electrical parameters and assumed charging station power. The study shows that every supply section of the considered trolleybus traction system has the capability of installing a fast-charging station, which provides opportunities of expanding the charging stations network in Gdynia.

  • APPLICATION POSSIBILITIES OF THE S960 STEEL IN UNDERWATER WELDED STRUCTURES
    • Jacek Tomków
    • Michał Landowski
    • Grzegorz Rogalski
    2022 Pełny tekst Facta Universitatis-Series Mechanical Engineering

    In this paper, the application possibilities of the ultra-high strength (UHSS). Domex 960 steel in the underwater welded structures are analyzed. In the research, the investigated material has been tested in bead-on-plate wet welding conditions with the usage of different heat input values, namely 0.63 kJ/mm, 0.72 kJ/mm and 0.93 kJ/mm. Specimens were performed by the manual metal arc (MMA) welding method with the usage of rutile covered electrodes. Firstly, the nondestructive visual testing (VT) was carried out. In the next step, the metallographic macro- and microscopic tests were performed. Finally, the hardness of the weld metal and heat-affected zone (HAZ) was measured by the Vickers HV10 method. The performed experiments allow the statement that the Domex 960 steel could be welded in a water environment. It also showed that increasing heat input leads to decreasing the hardness in HAZ by 30 HV10. It may result in decreasing the susceptibility to cold cracking during butt- and filet welding in the water environment.

  • Architectural and Urban Planning Solutions for the Protection of Heritage Buildings in the Context of Terrorist Attacks: Following the Example of Passive Protection Systems
    • Karol Grębowski
    • Aleksandra Wróbel
    2022 Pełny tekst Buildings

    Events in recent years showing numerous terrorist attacks raise awareness regarding the neces-sity of considering the safety of heritage buildings. The analysis of available data allows us to conclude that it is not possible to fully prevent terrorist attacks. On the other hand, it is possible to minimize the impact of such incidents through proper design of Passive Protection System (PPS) components. One possible architectural solution to be deployed as a passive defense system is laminated glass panel walls. The study presented in the article is innovative, considering there are no current standard documents or recommendations to determine the conditions of destruc-tion as well as the methods of testing the strength of glass components used in laminated glass panel walls under vehicle impact. The present work represents the material used in PVB inter-layers using the Mooney-Rivlin constitutive model, which correctly describes the non-linear characteristics of PVB. Based on the obtained results, new parameters of PVB laminated glass ex-posed to vehicle impact were developed. The newly developed parameters underwent quality verification through a comparison of results from experimental studies and digital simulations. Finally, the strength of laminated glass panel wall was subject to evaluation, considering the amount and thickness of individual VSG glass layers and the number of PVB interlayers at ground floor level of a heritage building with high susceptibility to terrorist attacks. The newly developed parameters of laminated glass may be implemented as a premade input .mat file for the material available in the KEYWORD database under the name MAT_32-LAMINATED_GLASS in LS-DYNA software.

  • Architectural Space of Ideas in the Author’s Structures Presented at the Fire Painted Images Art Festival: A Case Study
    • Agnieszka Kurkowska
    2022 Pełny tekst Loci Communes

    The article is aimed to discuss the place of architecture in the space of ideas. The present work discusses a specific place, the Zaspa housing estate in Gdańsk, and refers to a specific person, namely, the author of artistic installations tem- porarily exhibited in the Zaspa housing estate. Also, the wider context of the specific situations in which the exhibitions were displayed is presented. The article attempts to answer the question of the importance of the quality of dwelling in the context of the quality of life of city dwellers. The work focuses on the subjective quality of life, identified most often with the feeling of satisfaction with life in its various aspects and with mental well-being. The quality of living, in turn, may be defined as satisfaction with the structure and functioning of the house and its commonly shared surroundings that constitutes the context of such living. The installations exhibited in the Zaspa estate discussed in the following article represent a potential area for activities with which to change the landscape and/or architectural elements of housing estates that refer to the living space. The essence of the research lies in the analysis of the place architecture occupies in a wider context of the intangible spaces. Homes can be perceived in a phenomenological way. It this case, the spaces of the house are inside us, just as we are inside them (Bachelard, 1994).

  • Architecture Design of a Networked Music Performance Platform for a Chamber Choir
    • Jan Cychnerski
    • Bartłomiej Mróz
    2022 Pełny tekst Communications in Computer and Information Science

    This paper describes an architecture design process for Networked Music Performance (NMP) platform for medium-sized conducted music ensembles, based on remote rehearsals of Academic Choir of Gdańsk University of Technology. The issues of real-time remote communication, in-person music performance, and NMP are described. Three iterative steps defining and extending the architecture of the NMP platform with additional features to enhance its utility in remote rehearsals are presented. The first iteration uses a regular video conferencing platform, the second iteration uses dedicated NMP devices and tools, and the third iteration adds video transmission and utilizes professional low-latency audio and video workstations. For each iteration, the platform architecture is defined and deployed with simultaneous usability tests. Its strengths and weaknesses are identified through qualitative and quantitative measurements – statistical analysis shows a significant improvement in rehearsal quality after each iteration. The final optimal architecture is described and concluded with guidelines for creating NMP systems for said music ensembles.

  • Architektura kościołów dominikańskich w średniowiecznych Prusach
    • Piotr Samól
    2022

    Badania architektoniczne kościołów w Chełmnie, Elblągu, Gdańsku i Tczewie oraz próba rozpoznania danych na temat świątyni predykantów w Toruniu pozwoliły zrekonstruować historię budowlaną pięciu z nich. Poszczególne obiekty nigdy nie były realizowane w całości według z góry założonego planu. Proces ich projektowania i budowy to aż do przełomu XIV i XV wieku ciągłe modyfikacje, wpasowywanie się w kontekst przestrzenny miasta, zmiany potrzeb dominikanów. Jest znamienne, że niesamowicie intensywny pod względem prac budowlanych okres około 150 lat (ok. 1250 r. – ok. 1400 r.) zakończył się w czasie kryzysu gospodarczego i ideologicznego, który pojawił się w Prusach (i w instytucjach z nimi związanych) po przegranej „wielkiej wojnie” (l. 1409–1411) z Polską i Litwą. Skupienie się na niewielkich naprawach w obrębie kościołów i klasztorów w pierwszej połowie XV wieku wskazuje na silny wpływ kondycji gospodarczo-społecznej na życie zakonów żebraczych. Wraz z rozwojem demograficznym miast i wzrostem liczby zakonników dominikanie decydowali się na powiększanie swoich obiektów w części przeznaczonej dla wiernych. Dominikanie w średniowiecznych Prusach, otrzymując parcelę w nowo lokowanym mieście, wznosili swoją pierwszą świątynię w taki sposób, żeby umożliwić dalszą jej rozbudowę. Tak usytuowano kościoły w Chełmnie, Elblągu, Tczewie i Toruniu. Próba syntezowania i usystematyzowania architektury kościołów dominikańskich w Prusach była możliwa dzięki wieloletnim badaniom terenowym połączonym z analizą licznej literatury konfrontowanej z rozpoznanymi źródłami historycznymi i archeologicznymi. Świadomie ograniczono stosowanie metody porównawczej, wychodząc z założenia, że jej użycie jest możliwe dopiero wówczas, gdy znamy historię budowlaną poszczególnych obiektów, popartą materialnymi dowodami. Badania czterech średniowiecznych obiektów zachowanych do dziś i analiza jednego istniejącego jedynie w partii fundamentów pozwoliły zbudować bazę około trzydziestu zrekonstruowanych etapów i faz umiejscowionych chronologicznie. Stanowiła ona podstawę do rozpoznania schematów rozwojowych, którymi kierowali się dominikanie prowadzący prace budowlane przy swoich świątyniach. Takie podejście pozwala lepiej powiązać historię architektury z kontekstem społecznym, gospodarczym i przestrzennym, w jakim działali dominikanie. Ich obecność w miastach związana była wszak już z procesem lokacji, a dzieje świątyń są odbiciem nie tylko rozwoju urbanistycznego, ale i losów całego ośrodka.

  • Architektura proekologiczna: edukacja po dyplomie. Studia podyplomowe na Wydziale Architektury Politechniki Gdańskiej
    • Katarzyna Zielonko-Jung
    • Robert Idem
    2022 Architektura & Biznes

    Artykuł jest zawiera refleksji na temat edukacji architektów w Polsce w zakresie zrównoważonego rozwoju i zagadnień proekologicznych. Analizując program studiów oraz sposób nauczania na wydziałach architektury w Polsce, zauważyć można niedosyt treści programowych związanych z całościowym podejściem do tej problematyki. Brak też wypracowanych, powszechnych wzorców takiego podejścia w praktyce architektonicznych pracowni projektowych. Wiedzy w tym zakresie brak także architektom-urzędnikom opracowującym dokumenty planistyczne, współdecydującym o nowych inwestycjach i przekształceniach zabudowy istniejącej. Celem artykułu jest prezentacja założeń programowych studiów podyplomowych "Architektura proekologiczna" prowadzonych na Wydziale Architektury Politechniki Gdańskiej. Pierwsza edycja studiów uzyskała znaczne dofinansowanie Wojewódzkiego Funduszu Ochrony Środowiska i Gospodarki Wodnej w Gdańsku, który m.in. dzięki doświadczeniu budowy swojej nowej siedziby jako budynku energoaktywnego o wysokich standardach środowiskowych – docenił jak złożonym procesem jest projektowanie takich obiektów i jak wielu nowych kompetencji wymaga od architektów. Dofinansowanie pierwszej edycji studiów podyplomowych pozwoliło na staranne przygotowanie programu i pozyskanie kadry wykładowców z różnych ośrodków z Polski i zagranicy. W artykule zaprezentowano program studiów oraz podsumowano dotychczasowe efekty kształcenia.

  • Architektury klasyfikatorów obrazów
    • Konrad Zawora
    2022

    Klasyfikacja obrazów jest zagadnieniem z dziedziny widzenia komputerowego. Polega na całościowej analizie obrazu i przypisaniu go do jednej lub wielu kategorii (klas). Współczesne rozwiązania tego problemu są w znacznej części realizowane z wykorzystaniem konwolucyjnych głębokich sieci neuronowych (convolutional neural network, CNN). W tym rozdziale opisano przełomowe architektury CNN oraz ewolucję state-of-the-art w klasyfikacji obrazów na przestrzeni lat 2014--2021. Łącznie opisano 28 topologii głębokich konwolucyjnych sieci neuronowych, należących do 7 rodzin: EfficientNet, ResNet, DenseNet, Inception, NasNet, MobileNet oraz VGG.

  • Are Pair Trading Strategies Profitable During COVID-19 Period?
    • Muhammad Khalid Sohail
    • Abdul Raheman
    • Javid Iqbal
    • Muzammal Ilyas Sindhu
    • Abdul Staar
    • Muhammad Mushafiq
    • Humaira Afzal
    2022 Journal of Information & Knowledge Management

    Pair trading strategy is a well-known profitable strategy in stock, forex, and commodity markets. As most of the world stock markets declined during COVID-19 period, therefore this study is going to observe whether this strategy is still profitable after COVID-19 pandemic. One of the powerful algorithms of DBSCAN under the umbrella of unsupervised machine learning is applied and three clusters were formed by using market and accounting data. The formation of these three clusters was based on book value per share, earning per share, classification of sector, market capitalisation and with other factors formed from PCA on the returns of daily data of six months of the 80 sample firms for year 2019–2020. An average of 0:32% average excess monthly return with Sharpe ratio of 0:0012 and Treynor ratio of 0:0231 is to be observed in COVID-19 pandemic period. However, the result of risk-adjusted performance under Jensen's alpha is observed to be insignificant. The policy implication of this study, for different portfolios and fund managers is suggested to use machine learning approach to get positive and higher returns for their clients

  • ARIMA vs LSTM on NASDAQ stock exchange data
    • Dariusz Kobiela
    • Dawid Krefta
    • Weronika Król
    • Paweł Weichbroth
    2022 Pełny tekst Procedia Computer Science

    This study compares the results of two completely different models: statistical one (ARIMA) and deep learning one (LSTM) based on a chosen set of NASDAQ data. Both models are used to predict daily or monthly average prices of chosen companies listed on the NASDAQ stock exchange. Research shows which model performs better in terms of the chosen input data, parameters and number of features. The chosen models were compared using the relative metric mean square error (MSE) and mean absolute percentage error (MAPE). Selected metrics are typically used in regression problems. The performed analysis shows which model achieves better results by comparing the chosen metrics in different models. It is concluded that the ARIMA model performs better than the LSTM model in terms of using just one feature – historical price values – and predicting more than one time period, using the p, q parameters in the range from 0 to 2, Adam optimizer, tanh activation function, and 2xLSTM layer architecture. The longer the data window period, the better ARIMA performs, and the worse LSTM performs. The comparison of the models was made by comparing the values of the MAPE error. When predicting 30 days, ARIMA is about 3.4 times better than LSTM. When predicting an averaged 3 months, ARIMA is about 1.8 times better than LSTM. When predicting an averaged 9 months, ARIMA is about 2.1 times better than LSTM.

  • Artificial neural network based fatigue life assessment of friction stir welding AA2024-T351 aluminum alloy and multi-objective optimization of welding parameters
    • Reza Masoudi Nejad
    • Nima Sina
    • Danial Ghahremani Moghadam
    • Ricardo Branco
    • Wojciech Macek
    • Filippo Berto
    2022 Pełny tekst INTERNATIONAL JOURNAL OF FATIGUE

    In this paper, the fracture behavior and fatigue crack growth rate of the 2024-T351 aluminum alloy has been investigated. At first, the 2024-T351 aluminum alloys have been welded using friction stir welding procedure and the fracture toughness and fatigue crack growth rate of the CT specimens have been studied experimentally based on ASTM standards. After that, in order to predict fatigue crack growth rate and fracture toughness, artificial neural network is used. To obtain the best neuron number in the hidden layer of the artificial neural network, different neuron numbers are tested and the best network based on the performance is selected. Then the fitting method is applied and the fitted surfaces that illustrate the behavior of welding are shown and the results of artificial neural network and fitting method are compared. Also, multi-objective optimization algorithm is used to obtain the best welding parameters and finally sensitivity analysis is applied to measure the effect of rotational and traverse speeds on the fracture toughness and fatigue crack growth rate.

  • Asocjacje – jak gdyby, tak jakby…
    • Krzysztof Wróblewski
    2022

    Krzysztof Wróblewski prezentuje „In Touch / Anonymous”. (Twarz – jako maska, dłoń – jako dotyk i ślad) – dwa obrazy (olej na płótnie, wymiary: 146x228 cm) wraz z komentarzem: „W kuratorskim tekście do wystawy Asocjacje – jak gdyby, tak jakby zainteresował mnie cytat z teorii umysłu: jesteśmy świadomi umysłów innych ludzi i to ma wpływ na nasze poczynania i procesy umysłowe. Sztuka jako jedno z narzędzi komunikacji jest wysyłaniem i odczytywaniem sygnałów, opartym głównie na intuicji i sieci skojarzeń (asocjacji). Idąc tym tropem i odpowiadając na temat wystawy, połączyłem we wspólny sygnał dwa obrazy: „In Touch” oraz „Anonymous”. Obraz „In touch” to chęć zbudowania metafory tego, czego wszyscy doświadczali na początku pierwszego zamknięcia w marcu 2020 roku podczas wybuch pandemii Covid-19. Popularny w języku angielskim zwrot wyrażający bycie w kontakcie zawierał w sobie problematyczny wtedy rzeczownik „dotyk”. Kontakt to dotyk – fizyczny ale też mentalny. (…) Impulsem do namalowania niewielkiego obrazu „Anonymous” były akcje przeprowadzone przez internetowe grupy hakerów, których celem było wspomagania Ukrainy w jej walce przeciwko militarnej agresji Rosji. Anonimowi aktywiści ukrywają twarze pod maską Guya Fawkesa, która rozpowszechniła się po 2006 roku wśród różnych grup protestacyjnych występujących przeciwko rządom, bankom i instytucjom finansowym. Maska chroni nie tylko tożsamość buntowników, ale symbolizuje też ich zjednoczenie we wspólnej sprawie. Aktywiści Anonymous nie są anarchistami lecz rebeliantami, którzy sprzeciwiają się ograniczaniu wolności oraz agresji. Świat tworzą i zmieniają dłonie miliardów ludzi, których twarze przybiera ją wielorakie maski. Skala ich dokonań ma różne rozmiary – od prawie niewidocznych po gigantyczne. Jak powiedział Juhani Pallasmaa: „Dłonie stanowią część indywi dualnej osobowości i charakteru, ale wykonują również swoje niezależne działania, i jako wyposażone we własny język, mają kluczowe znaczenie dla ludzkiej komunikacji”. Łącząc dwa obrazy w jeden przekaz chcę powiedzieć, że potrzebujemy symboli i znaków, które jednoczą często bezimienne działania i losy. Wierzę w myślące oblicze dłoni”. Krzysztof Wróblewski

  • Aspekty formalno-prawne współczesnej gospodarki energetycznej
    • Waldemar Kamrat
    2022

    Przedstawiono najbardziej istotne akty prawne , dyrektywy,zarządzenia rozporządzenia regulujące procesy gospodarowania energią

  • Assessing Roadside Hybrid Energy Absorbers Using the Example of SafeEnd
    • Marcin Budzyński
    • Kazimierz Jamroz
    • Łukasz Jeliński
    • Dawid Bruski
    • Łukasz Pachocki
    • Grzegorz Baginski
    2022 Pełny tekst Materials

    A combination of crash cushion and end-terminal, hybrid energy absorbing devices have been in use worldwide for a few years already. They include SafeEnd, a system Poland has recently introduced. Some road authorities have raised concerns as regards the operating conditions of the devices and how they work together with safety barriers. The objective of this research is to clarify the concerns and answer the following questions: (1) Can SafeEnd devices be used as hybrid devices and combine the roles of end-terminal and crash cushion placed before an obstacle? (2) What should be the rules for installing crash cushions at diverging roads and at the start of an off-ramp? The article presents characteristics of SafeEnd devices, defines the doubts raised by road safety auditors, discusses the results of field and numerical tests of the devices and explains the design principles for interchange ramps where crash cushions are required. The study results have helped to answer the research questions: SafeEnd devices fulfil the role of end-terminal and crash cushion, it is possible to make them more visible and principles have been defined for how the devices should be used at road interchanges. Further research should help to define general principles of deploying road restraint systems such as crashworthy terminals, crash cushions or hybrid devices.

  • Assessment of Adjustment of GNSS Railway Measurements with Parameter-Binding Conditions in a Stationary Scenario
    • Pawel S. Dabrowski
    • Cezary Specht
    • Mariusz Specht
    • Paweł Burdziakowski
    • Oktawia Lewicka
    2022 Pełny tekst Applied Sciences-Basel

    The study aims to assess the applicability of the ordinary least squares method, robust estimation, and conditions-binded adjustment in processing the six synchronous coordinate pairs of global navigation satellite system (GNSS) receivers. The research is part of the research project InnoSatTrack, focused on the enhancement of the determination of geometrical parameters of railway tracks using GNSS, inertial, and other sensors. A fixed frame of installation of six receivers is used in the data processing. Due to the limited availability of railway routes for measurements, the stationary campaign was conducted to gather data for the adjustment procedures tests. Six GNSS receivers in the frame-restricted configuration were set up using the tachymetric method for recording 96,729 synchronous static observations. Post-processed coordinates of the receivers were adjusted according to the geometrical conditions of the survey frame. Analysis showed higher applicability of the conditions-binded method than other estimation methods by obtaining superior results in both the precision and the maintenance of the design conditions factors than in the OLS and robust estimators.

  • Assessment of E-government inclusion policies toward seniors: A framework and case study
    • Magdalena Ciesielska
    • Nina Rizun
    • Jakub Chabik
    2022 Pełny tekst TELECOMMUNICATIONS POLICY

    Digital exclusion of seniors covers both social and technical drivers that affect the magnitude of this phenomenon. It arises from the fear of technology, reduced manual and mental abilities, socio-economic status, and also the mismatch between the technological environment and the needs of the elderly. The consideration of the needs of seniors are mainly implemented through social policies while the provision of government services is achieved through digitization policies and procedures. Our research is addressing two objectives. The first objective is to identify the main determinants affecting the adoption of e-government and its use by seniors. The second objective is to build a research framework for assessing e-government policy for the digital inclusion of the seniors from both social and technical perspectives. This research framework is then validated based on a case study of Poland. Presented framework proves to be a useful tool to evaluate and depict the areas of improvement for a comprehensive e-government policy toward seniors' inclusion.

  • Assessment of Environmental Loads in the Life Cycle of a Retail and Service Building
    • Daniel Tomporowski
    • Robert Kasner
    • Wojciech Franus
    • Krzysztof Doerffer
    2022 Pełny tekst ENERGIES

    In order to achieve the European Union’s climate and energy goals, investments are required, mainly in the areas of energy efficiency, renewable energy sources and infrastructure. Buildings are responsible for almost half of total energy consumption, and nearly 80% of them are energy and ecologically inefficient. The policy of European countries is increasingly more focused on facilities with the highest potential in the areas of energy and matter saving and the possibly circular economy. The aim of the work was to assess the environmental loads occurring in the life cycle of an existing retail and service building. The analysis was performed using the Life Cycle Assessment (LCA) method. By using the IMPACT 2002+ model, it has become possible to assess the impact of the life cycle of the studied facility on human health, environmental quality, climate change and raw material resources. The highest level of negative consequences in the above-mentioned areas was recorded for the life cycle with the disposal in the form of landfill storage. The operational stage was the stage in the life cycle that caused the most harmful impacts on the environment. Therefore, it is necessary to optimize the ecological and energy consumption of resources, for example, by selecting the size and cubature of the facility for its function, maintaining good technical condition, introducing improvements in the usage processes or implementing solutions aimed at reducing media consumption. As a result of the conducted analyses, it can be noticed that in the future, the reduction in energy consumption in the operation of buildings will be of fundamental importance.

  • Assessment of River Water Quality and Pollution Status Using Physicochemical and Biometrics, Awetu River, Ethiopia
    • Dessalegn Geleta Ebsa
    • Worku Firomsa Kabeta
    2022 Pełny tekst GEOFLUIDS

    The surface water is contaminated by a variety of synthetic organic and inorganic compounds, chemicals, and nutrients; due to this reason, the quality of the water resources of Ethiopia is declining at an alarming rate, resulting in severe environmental degradation. The main objective of the study was to recognize the pollution status river for the study area by physicochemical parameters and the extent of microbial environmental matrices. The experiment was conducted using a complete randomized model with three composite replicates in each site, and water samples were collected from six different sampling sites using the American Public Health Association (APHA) technique. Water quality parameters were analyzed by the standard method of examination, whereas same examination was determined on site (in situ) (pH, Temp, Conductivity, and Turbidity), whereas TSS, COD, BOD, nitrate, alkali, and orthophosphate were identified in the laboratory. The relationship between physicochemical and benthos assemblages as bio indicators of ecohydrological river water quality was investigated using Spearman’s median rank correlation. The output of the study reveals that there was a negatively significant difference in effect between the sample and all the sites of the river. Physicochemical results of the river indicate Temp (23.62), EC (101.42), nitrate (2.175), and orthophosphates (0.081) were below the standard guidelines; however, turbidity (8.41), BOD (784.5), and alkali (396.5) were above the standard. Same of the water quality values for this study were ranges within the standard, DO (5.11), and pH (7.66). The benthos assemblage communities of the ecohydrological area were more influenced by the influents,and the macroinvertebrate index of all sample sites indicates the Shannon and Simpson diversity indices; result shows that the river was lightly polluted.

  • Assessment of the application of CEM III with exposed aggregate as an alternative to CEM I for road pavements
    • Marzena Kurpińska
    • Aldona Wcisło
    2022 Pełny tekst Archives of Civil Engineering

    The article presents a results of study on the impact of replacing CEM I SR3/NA by CEMIII/A LH/HSR/NAon the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement () ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana – zeolite. Compressive strength tests were performed after 3, 7, 28 and 56 days, tests of tensile strength test by splitting method and flexural strength two-point loading tests. The characteristics of the air pores and the rate of water absorption by concrete surface of the samples cut out from the slabs with exposed aggregate were presented. The resistance of the surface to exfoliation after 56 cycles of freezing-thawing in NaCl solution was tested. Based on the results obtained, it was found that when designing the composition of the concrete intended for the upper layer of the pavement, it is necessary to ensure high tensile strength, appropriate in the XF4 environment and with the decrease in the  Ÿ 0•4, a reduction in capillary porosity of the cement paste is obtained, and the same the durability of concrete is increased due to the improved strength parameters in the contact zone between coarse aggregate grains and cement paste. The research also showed a significant influence of proper cure on the mechanical properties and durability of pavement concrete.

  • Assessment of the Current Potential of Hydropower for Water Damming in Poland in the Context of Energy Transformation
    • Bartłomiej Igliński
    • Krzysztof Krukowski
    • Jarosław Mioduszewski
    • Michał Pietrzak
    • Mateusz Skrzatek
    • Grzegorz Piechota
    • Sebastian Wilczewski
    2022 Pełny tekst ENERGIES

    The present paper indicates that hydropower, including small hydropower plants (SHPs), may play a very important role in Poland’s energy transformation in the near future. The development of SHPs may also increase water resources in the steppe Poland. Additionally, the aim of the present research is to conduct the PEST analysis of SHPs in Poland, taking into account the SHP potential. For the first time, maps showing the power and location of potential SHPs on the existing dams in Poland are presented. SHPs should be an important element of energy transition in Poland, especially on a local scale—it is stable energy production. Our analysis shows that there are 16,185 such dams in Poland, while the total capacity of potential hydropower plants in Poland would be 523.6 MW, and the total number of new jobs is estimated at 524. It was calculated that the annual avoided carbon dioxide emissions will amount to 4.4 million tons, which will reduce Poland’s emissions by 1.4%. The construction of SHPs can bring significant environmental and economic benefits. As far as the PEST analysis is concerned, the political environment of SHPs in Poland can be described as unfavorable (2.86 points). The economical nature of PEST analysis (3.86 points) should be considered as friendly for the development of SHPs. The social nature of PEST analysis can be considered as neutral (3.36 points). The technological nature of the PEST analysis can be considered as neutral (3.21 points)

  • Assessment of the Feasibility of Energy Transformation Processes in European Union Member States
    • Michał Pietrzak
    • Magdalena Olczyk
    • Marta Kuc-Czarnecka
    2022 Pełny tekst ENERGIES

    The energy transition is now treated in most countries as a necessary condition for their long-term development. The process of energy transformation assumes the simultaneous implementation of the Sustainable Development Goals, which are a major challenge for modern economies and introduce significant restrictions in their functioning. Our study aims to group EU member states according to their ability to achieve energy transition over time . The novelty of our approach is the assessment of energy transformation in the European Union through two aspects. The first one, “smart and efficient energy systems”, assess the current, widely understood energy consumption in economy, and the second one, “macroeconomic heterogeneity”, refers to the economic potential of a country. In our analysis, we included indicators from the 7th, 8th, 10th, 11th, and 12th Sustainable Development Goals. Using taxonomic methods, we created clusters of coun-tries according to the emissivity of their economies and the socio-economic potential for the energy transition. The analysis results revealed that countries vary more due to their emissivity than economic potential.

  • Assessment of unusual failure in crankshaft of heavy-duty truck engine
    • Karim Aliakbari
    • Reza Masoudi Nejad
    • Sayed Kian Pourhosseini Toroq
    • Wojciech Macek
    • Ricardo Branco
    2022 Pełny tekst ENGINEERING FAILURE ANALYSIS

    The unusual premature failure of a heavy-duty truck engine crankshaft has been the subject of a rigorous study, and this manuscript describes it in detail. The failure was happened to begin with the growth of the crack from the surface defects, in the form of the clusters of non-metallic inclusions, in the lubrication hole zone of the first main journal, which was the stress concentration zone. A series of experiments including chemical composition, microstructure, mechanical properties, hardness, toughness, and fractography were performed on the failed crankshaft. In addition, the stress analysis was performed on the crankshaft. Careful fractographic study with scanning electron microscopy equipped with energy dispersive spectroscopy revealed that failure with cluster inclusions MnS ( = ⁄ = 0 ∙ 024 > 0 ∙ 01) was more than the standard amount. Besides, stress analysis showed that the stress field in stress concentration zones with the lubricating hole is much less than the web-crankpin fillet but the presence of cluster impurities, low hardness (> 600 HV0.1 proposed standard), downshifting has caused the growth of primary cracks. It is recommended to first increase the hardness by about 43% and then, decrease the size of non-metallic inclusions so that primary crack growth does not initiate from the worst clusters of inclusions.

  • ASSESSMENT OF WEAR OF THE BANDSAW TEETH IN INDUSTRIAL CONDITIONS
    • Kazimierz A. Orlowski
    • Daniel Chuchala
    • Dawid Stenka
    • Tomasz Przybyliński
    2022 Pełny tekst ACTA FACULTATIS XYLOLOGIAE ZVOLEN

    A methodology for measuring bandsaw tooth wear is presented in this paper. This type of measurement is proposed as an alternative way of determining tooth wear in industrial conditions. The method is based on determining the KE value, i.e., the distance of the radius of the rounded cutting edge of the tooth and the intersection of the surface of the back and the surface of the face of the cutting wedge of the bandsaw tooth. The rate of wear of bandsaw teeth is determined by comparing the measured value with the KE values given in the literature. During the development of the methodology, experimental cutting tests were performed at a sawmill that specializes in the production of floors from multi-layer glued laminated wooden boards. The investigated band saw was applied in the sawing process of oak (Quercus L.) boards. The average moisture content of the wood was MC = 32.9% when using the "wet" technology of lamella production. Since the monitored wear values are not very high, the use of certified measuring instruments is strongly recommended.

  • Asynchroniczna metoda jednoczesnej estymacji położenia i orientacji obiektu za pomocą dwóch nadajników
    • Jacek Stefański
    • Jarosław Sadowski
    2022 Pełny tekst Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule opisano nową metodę lokalizowania obiektów dla szerokiej gamy zastosowań, w tym Internetu Rzeczy. Zaproponowana metoda umożliwia estymację położenia i orientacji obiektu na płaszczyźnie lub w przestrzeni, również będącego w spoczynku, za pomocą sygnałów lokalizacyjnych wysyłanych jednocześnie z dwóch nadajników umieszczonych na obiekcie w znanej odległości od siebie. Przedstawiono matematyczną analizę metody oraz wyniki badań symulacyjnych efektywności pracy zaproponowanej metody.

  • Atomic-Scale Finite-Element Modeling of Elastic Mechanical Anisotropy in Finite-Sized Strained Phosphorene Nanoribbons
    • Krzysztof Pyrchla
    • Robert Bogdanowicz
    2022 Pełny tekst Journal of Physical Chemistry C

    Nanoribbons are crucial nanostructures due to their superior mechanical and electrical properties. This paper is devoted to hybrid studies of the elastic mechanical anisotropy of phosphorene nanoribbons whose edges connect the terminals of devices such as bridges. Fundamental mechanical properties, including Young’s modulus, Poisson’s ratio, and density, were estimated from first-principles calculations for 1-layer, 3-layer, and 6-layer nanoribbons with widths of 10 Å. The data achieved from the ab initio simulations supplied the finite-element model (FEM) of the nanoribbons. The directional coefficients of strain pressure curves were estimated as Young’s effective modulus since the structure is one-dimensional (1D). The modulus values were equal to 85.8, 111.8, and 134 GPa for 6, 3 and 1 layers, respectively. Moreover, the variation in Poisson’s coefficient for the armchair direction was significantly smaller than for the zigzag direction. Monotonic changes in this twist were observed for structures with 3 and 6 layers within the plane along the zigzag axis. The phosphorene nanoribbons subjected to periodic excitation behaved similarly to those subjected to static loading, while their whippiness was inversely proportional to the length. Next, the deflection under static force, resonance frequencies, and response to a variable driving force were calculated.

  • Automatic Breath Analysis System Using Convolutional Neural Networks
    • Zdzisław Kowalczuk
    • Michał Czubenko
    • Michał Bosak
    2022

    Diseases related to the human respiratory system have always been a burden for the entire society. The situation has become particularly difficult now after the outbreak of the COVID-19 pandemic. Even now, however, it is common for people to consult their doctor too late, after the disease has developed. To protect patients from severe disease, it is recommended that any symptoms disturbing the respiratory system be detected as early as possible. This article presents an early prototype of a device that can be compared to a digital stethoscope that performs auto-breath analysis. So apart from recording the respiratory cycles, the device also analyzes them. In addition, it also has the functionality of notifying the user (e.g. via a smartphone) about the need to go to the doctor for a more detailed examination. The audio recording of breath cycles is transformed to a two-dimensional matrix using mel-frequency cepstrum coefficients (MFCC). Such a matrix is analyzed by an artificial neural network. As a result of the research, it was found that the best of the obtained solutions of the presented neural network achieved the desired accuracy and precision at the level of 84\%.

  • Automatic Breath Analysis System Using Convolutional Neural Networks
    • Zdzisław Kowalczuk
    • Michał Czubenko
    • Michał Bosak
    2022

    Diseases related to the human respiratory system have always been a burden for the entire society. The situation has become particularly difficult now after the outbreak of the COVID-19 pandemic. Even now, however, it is not uncommon for people to consult their doctor too late, after the disease has developed. To protect patients from severe disease, it is recommended that any symptoms disturbing the respiratory system be detected as early as possible. This article presents an early prototype of a device that can be compared to a digital stethoscope that performs auto-breath analysis. So apart from recording the respiratory cycles, the device also analyzes them. In addition, it also has the functionality of notifying the user (e.g. via a smartphone) about the need to go to the doctor for a more detailed examination. The audio recording of breath cycles is transformed to a two-dimensional matrix using mel-frequency cepstrum coefficients (MFCC). Such a matrix is analyzed by an artificial neural network. As a result of the research, it was found that the best of the obtained solutions of the presented neural network achieved the desired accuracy and precision at the level of 84%.

  • Automatic classification and mapping of the seabed using airborne LiDAR bathymetry
    • Łukasz Janowski
    • Paweł Tysiąc
    • Radosław Wróblewski
    • Maria Rucińska
    • Agnieszka Kubowicz- Grajewska
    2022 Pełny tekst ENGINEERING GEOLOGY

    Shallow coastal areas are among the most inhabited areas and are valuable for biodiversity, recreation and the economy. Due to climate change and sea level rise, sustainable management of coastal areas involves extensive exploration, monitoring, and protection. Current high-resolution remote sensing methods for monitoring these areas include bathymetric LiDAR. Therefore, this study presents a novel methodological approach to assess the suitability of Airborne LiDAR Bathymetry for automatic classification and mapping of the seafloor. Nine classes of geomorphological bedforms and three classes of anthropogenic structures were identified. They were automatically mapped by Geographic Object-Based Image Analysis and machine learning supervised classifiers. The developed method was applied to six study sites and a 48 km submerged coastal zone in the Southern Baltic, achieving an overall accuracy of up to 94%. This study shows that calculation of the Multiresolution Index of Ridge Top Flatness (secondary feature) can be used to quickly and automatically determine sandbar crests and ridge tops. The methodical approach developed in this study can help evaluate and protect other shallow coastal environments and coastal protection structures.

  • Automatic Emotion Recognition in Children with Autism: A Systematic Literature Review
    • Agnieszka Landowska
    • Aleksandra Karpus
    • Teresa Zawadzka
    • Ben Robins
    • Duygun Erol Barkana
    • Hatice Kose
    • Tatjana Zorcec
    • Nicholas Cummins
    2022 Pełny tekst SENSORS

    The automatic emotion recognition domain brings new methods and technologies that might be used to enhance therapy of children with autism. The paper aims at the exploration of methods and tools used to recognize emotions in children. It presents a literature review study that was performed using a systematic approach and PRISMA methodology for reporting quantitative and qualitative results. Diverse observation channels and modalities are used in the analyzed studies, including facial expressions, prosody of speech, and physiological signals. Regarding representation models, the basic emotions are the most frequently recognized, especially happiness, fear, and sadness. Both single-channel and multichannel approaches are applied, with a preference for the first one. For multimodal recognition, early fusion was the most frequently applied. SVM and neural networks were the most popular for building classifiers. Qualitative analysis revealed important clues on participant group construction and the most common combinations of modalities and methods. All channels are reported to be prone to some disturbance, and as a result, information on a specific symptoms of emotions might be temporarily or permanently unavailable. The challenges of proper stimuli, labelling methods, and the creation of open datasets were also identified.

  • Autonomiczny system zdalnego pomiaru wentylatorów przemysłowych jako rezultat etapu projektu innowacyjnego
    • Marian Piwowarski
    • Paweł Ziemiański
    • Jacek Czyżewicz
    • Mateusz Bortkiewicz
    • Krzysztof Laszuk
    • Ireneusz Galara
    • Marta Pawłowska
    • Karol Cybulski
    2022 Instal

    W artykule przedstawiono proces budowania oraz testowania zdalnego, całkowicie autonomicznego systemu pomiaru parametrów pracy wentylatorów. Proces realizowano w ramach pierwszego etapu innowacyjnego projektu. Przedstawiono szczegółowe kroki budowy systemu zbierania i przetwarzania danych pomiarowych z wentylatorów zainstalowanych w rzeczywistych warunkach eksploatacji oraz wyniki ich analizy. W szczególności opracowano i wdrożono infrastrukturę pomiarową w tym również zdefiniowano zestaw niezbędnej aparatury pomiarowej. Zamontowano aparaturę pomiarową na wyselekcjonowanych instalacjach z odpowiednimi wentylatorami. Wdrożono systemy pozwalające na ciągłe pomiary parametrów instalacji, zdalny przesył danych na serwer, gdzie poddawany jest bieżącej analizie i selekcji zebranych danych do wykorzystania w procesie modelowania i diagnostyki. Zweryfikowano eksperymentalnie zadowalający stopień korelacji między wyselekcjonowanymi parametrami mierzonymi w warunkach rzeczywistych, a charakterystyką wentylatora i instalacji. Wyznacznikiem tego było znalezienie czterech istotnych statystycznie parametrów na poziomie ufności 95%.

  • Autonomous Control of the Underwater Remotely Operated Vehicle in Collision Situation with Stationary Obstacle
    • Roman Śmierzchalski
    • Maciej Kapczyński
    2022 Pełny tekst Polish Maritime Research

    The article considers the problem of autonomous control of the underwater remotely operated vehicle mini Remotely Operated Vehicle (ROV) in a collision situation with a stationary obstacle. The control of the collision avoidance process is presented as a synthesis of fuzzy proportional-differential controllers for the control of distance and orientation concerning the detected stationary obstacle. The control of the submergence depth of the underwater vehicle has been adopted as a separate control flow. A method to obtain the main motion parameters of the underwater vehicle relative to the detected stationary obstacle using a Laser-based Vision System (LVS) and a pressure sensor coupled to an Inertial Measurement Unit (IMU) is described and discussed. The result of computer implementation of the designed fuzzy controllers for collision avoidance is demonstrated in simulation tests and experiments carried out with the mini ROV in the test pool.

  • Autonomous Perception and Grasp Generation Based on Multiple 3D Sensors and Deep Learning
    • Zdzisław Kowalczuk
    • Jan Glinko
    2022

    Grasping objects and manipulating them is the main way the robot interacts with its environment. However, for robots to operate in a dynamic environment, a system for determining the gripping position for objects in the scene is also required. For this purpose, neural networks segmenting the point cloud are usually applied. However, training such networks is very complex and their results are unsatisfactory. Therefore, we propose an innovative and end-to- end approach to generating the grip position that replaces (3D) point cloud segmentation with 2D image segmentation. For this purpose, we create an OrthoView module that acts as an adapter between 3D space (point cloud) and 2D space (image). The 2D object mask created in it serves as basic information in the process of selecting the final grip from among the grips generated for the entire scene using Contact GraspNet. An unquestionable conceptual advantage of our solution (OrthoView) is the fact that only one resulting 2D image is created from the point cloud, which can be the result of merging (integrating) 3D images from many cameras. Therefore, it allows for the fusion of information from any number of cameras, without the need to implement solutions for identifying the same objects seen from different perspectives (cameras). In order to test our solution stream, we created 6 scenes of different complexity, on the basis of which we present the effectiveness of our solution. In summary, eliminating the need for 3D point cloud segmentation and reducing the image segmentation problem to infer from only one 2D photo can significantly improve the performance of the position estimation system for grasping objects.

  • Autonomous pick-and-place system based on multiple 3Dsensors and deep learning
    • Zdzisław Kowalczuk
    • Jan Glinko
    2022

    Grasping objects and manipulating them is the main way the robot interacts with its environment. However, for robots to operate in a dynamic environment, a system for determining the gripping position for objects in the scene is also required. For this purpose, neural networks segmenting the point cloud are usually applied. However, training such networks is very complex and their results are unsatisfactory. Therefore, we propose an innovative and end-to- end approach to generating the grip position that replaces (3D) point cloud segmentation with 2D image segmentation. For this purpose, we create an OrthoView module that acts as an adapter between 3D space (point cloud) and 2D space (image). The 2D object mask created in it serves as basic information in the process of selecting the final grip from among the grips generated for the entire scene using Contact GraspNet. An unquestionable conceptual advantage of our solution (OrthoView) is the fact that only one resulting 2D image is created from the point cloud, which can be the result of merging (integrating) 3D images from many cameras. Therefore, it allows for the fusion of information from any number of cameras, without the need to implement solutions for identifying the same objects seen from different perspectives (cameras). In order to test our solution stream, we created 6 scenes of different complexity, on the basis of which we present the effectiveness of our solution. In summary, eliminating the need for 3D point cloud segmentation and reducing the image segmentation problem to infer from only one 2D photo can significantly improve the performance of the position estimation system for grasping objects.

  • BADANIA JAKOŚCI BEZSZWOWYCH DRUTÓW PROSZKOWYCH
    • Adrian Wolski
    2022 Pełny tekst

    Proces spawania drutami proszkowymi (FCAW) zyskuje coraz większą popularność w różnych dziedzinach przemysłu. Przemysł stoczniowy oraz offshore znacznie częściej wykorzystuje tę metodę przy wykonywaniu odpowiedzialnych i masywnych konstrukcji, których nie można wykonać stosując metody w pełni zautomatyzowane, np. spawanie łukiem krytym. Wzrost zainteresowania tą metodą spowodowany jest przez wysoką wydajność procesu spawania, łatwość opanowania tej metody przez spawaczy, możliwości spawania szerokiego zakresu materiałów i fakt, że charakter tej metody sprzyja wytwarzaniu złączy dobrej jakości (pozbawionego wad). Celem pracy była weryfikacja wpływu przechowywania bezszwowych drutów proszkowych do metody spawania FCAW w warunkach przemysłowych. W tym celu przechowywano trzy wybrane gatunki drutów na terenie przedsiębiorstwa w strefie przemysłowej w Elblągu (województwo warmińsko-mazurskie), a następnie wykonano badania metalograficzne i oznaczono ilość wodoru dyfundującego w stopiwie. Wyniki porównano z wartościami uzyskanymi dla tych samych drutów w stanie dostawy.

  • Badania nieniszczące czopów łopatek turbiny Hz3 EW Straszyn na obecność pęknięć nieciągłości
    • Wojciech Kiełczyński
    • Jacek Haras
    2022

    Celem badań była identyfikacja wad materiałowych na czopach łopatek Hz3 w turbinie Kaplana , na podstawie następujących badań: - wizualnych (VT), - magnetyczno proszkowych (MT), ultradźwiękowych. Na podstawie w/w badań poszczególnych stref pomiarowych, dokonano oceny wadliwości materiału 4 czopów łopatek, łączących łopatki z wieńcem Hz3, z punktu widzenia inicjacji pęknięć. Wynik badań przekazano Zleceniodawcy.

  • Badania połączeń spawanych rurociągu wody pitnej we Włocławku, ang. Welding joints tests in drinking water pipeline.
    • Wojciech Kiełczyński
    • Maria Głowacka
    • Lech Nadolny
    • Marian Siejka
    2022

    Celem badań opisanych w pracy było określenie przyczyn korozji powstałej w strefie wpływu ciepła (SWC) w obwodowych połączeniach spawanych w rurociągu wody pitnej. Materiałem, z którego wykonano rurociąg to stal 304/304L. W obszarze złącza spawanego stwierdzono wżery inicjowane od niezgodności geometrycznych, gdzie mogły gromadzić się osady zwiększające udział chlorków bezpośrednio przy powierzchni rury, promujące tym procesy korozyjne. Należy stwierdzić, że intensywna korozja występująca w SWC w badanej próbce była spowodowana procesem spawania, nieadekwatnym do zaistniałych okoliczności i niespełnieniem warunków metalurgicznych dla spawanego materiału. Wymienić tu należy: - zbyt dużą energie liniową wpływającą na tworzenie nadmiernego, dużego przekroju poprzecznego spoiny. - niewłaściwie prowadzony proces technologiczny w kwestii przygotowania i dopasowania krawędzi łączonych co prowadziło do niezamierzonych osadzeń cząsteczek stałych, zawierających między innymi chlorki, - niedostateczna osłona grani spoiny gazem osłonowym (Ar) w trakcie wykonywania warstwy przetopowej. Fakt ten spowodowało trwałe uszkodzenie warstwy pasywacyjnej i nadmierny spadek poziomu chromu umożliwiając tym samym rozpoczęcie procesu korozji w SWC.

  • Badania porównawcze wpływu grubości ścianki powłoki o przekroju niekołowym, wykonanej z tworzywa GRP, w obiekcie gruntowo-powłokowym
    • Remigiusz Gut
    • Wiktor Jasiński
    • Andrzej Duszyński
    • Aleksander Czapla
    • Jakub Drewnowski
    2022 Pełny tekst Materiały Budowlane

    W artykule przedstawiono badania porównawcze przepustów wykonanych z tworzywa GRP (Glass Reinforcement Poliester) zabudowanych w warunkach naturalnych i obciążanych układem sił symulujących obciążenia komunikacyjne zgodne z „Modelem Obciążenia 1” wg [7]. Analizowano dwie konstrukcje o identycznym przekroju poprzecznym (profil dzwonowy DN3000/2400), ale różnej grubości ścianki: standardowej 45 mm i zredukowanej 35 mm. Badania obejmowały pomiary przemieszczeń pionowych i poziomych konstrukcji oraz odkształceń ścianki w części środkowej odcinka i przy złączu. Wyniki badań poddano analizie w celu sprawdzenia wpływu redukcji grubości ścianki na odkształcenia wewnętrznego przekroju konstrukcji oraz na naprężenia w ściankach.

  • Badanie jakości transmisji w sieciach komórkowych na przestrzeni lat 2019-2021: wpływ pandemii Covid-19 na poziom świadczonych usług
    • Przemysław Falkowski-Gilski
    • Tadeus Uhl
    2022 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Pandemia COVID-19 znacząco ograniczyła mobilność użytkowników, a w szczególności studentów. Nauka zdalna miała szczególny wpływ na sposób przydziału zasobów w sieciach komórkowych. Niniejsza praca przedstawia wyniki badań dotyczących jakości transmisji w środowisku zewnątrzbudynkowym. Kampanię pomiarową w latach 2019-2021 przeprowadzono na terenie kampusu uczelni technicznej. Każdego roku badania wykonano przy użyciu własnej autorskiej aplikacji mobilnej, zainstalowanej na 50 smartfonach działających pod kontrolą systemu Android.

  • Badanie wpływu przydziału rdzeni procesora na wydajność w środowisku skonteneryzowanym oparte na wybranym serwerze warstawy pośredniej w IoT - obserwacje i rekomendacje
    • Robert Kałaska
    2022

    Internet Rzeczy cieszy się coraz większym zainteresowaniem. Za- gadnienie to jest szeroko omawiane zarówno w środowisku nauko- wym, jak i w przemyśle. Ze względu na jego wielowymiarowość jest wiele aspektów, które wymagają zbadania i obserwacji. Jednym z nich jest efektywne wdrożenie i uruchomienie aplikacji w kontekście wykorzystania zasobów sprzętowych. Innym, równie istotnym, za- gadnieniem jest konteneryzacja platform IoT. Jednym ze wspólnych obszarów dla obu tych zagadnień jest analiza wydajności w środowisku skonteneryzowanym dla różnych konfiguracji przydziału rdzeni procesora. To zagadnienie zostało zbadane w niniejszym rozdziale na podstawie z otwartych platform dla IoT – DeviceHive. Zmie- rzone zostały skalowalność i stabilność rozwiązania w różnych kon- figuracjach węzłów i przypisanych im rdzeni. Najciekawsze wnioski zostały wyciągnięte z obserwacji tych samych konfiguracji w kon- tekście liczby węzłów, a różniących się sposobem przypisania rdzeni. Przedstawione wyniki mogą być przydatne w zakresie planowania architektury rozwiązań skonteneryzowanych platform IoT.

  • Bayesian Optimization for solving high-frequency passive component design problems
    • Michał Baranowski
    • Grzegorz Fotyga
    • Adam Lamęcki
    • Michał Mrozowski
    2022 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    In this paper, the performance of the Bayesian Optimization (BO) technique applied to various problems of microwave engineering is studied. Bayesian optimization is a novel, non-deterministic, global optimization scheme that uses machine learning to solve complex optimization problems. However, each new optimization scheme needs to be evaluated to find its best application niche, as there is no universal technique that suits all problems. Here, BO was applied to different types of microwave and antenna engineering problems, including matching circuit design, multiband antenna and antenna array design, or microwave filter design. Since each of the presented problems has a different nature and characteristics such as different scales (i.e. number of design variables), we try to address the question about the generality of BO and identify the problem areas for which the technique is or is not recommended

  • Behavior of residual current devices at earth fault currents with DC component
    • Stanisław Czapp
    • Hanan Tariq
    • Sławomir Cieślik
    2022 Pełny tekst SENSORS

    Low-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing both these systems should be recognized from the point of view of earth fault current waveform shapes. In such installations, various shapes of the earth fault current may occur – a DC component of a high value may especially flow. The DC component included in the earth fault current influences the tripping threshold of residual current devices (RCDs) – the devices which are mandatory in certain locations. This paper presents results of the AC-type, A-type, and F-type RCDs sensitivity testing under residual currents of various compositions of the DC component. This testing has shown that the DC component may both degrade and improve the sensitivity of RCDs. Moreover, unexpected positive behaviors of RCDs in some circumstances under DC residual current is discussed. Therefore, recognizing the real sensitivity and behavior of RCDs from the point of view of the DC component is important for effective protection against electric shock, in particular, in PV installations and EV charging systems. The research results provide a new insight into the real behavior of RCDs in modern power systems and, consequently, the safety of people.

  • Benchmarking the Digital Government Value Chain
    • Jaromir Durkiewicz
    • Tomasz Janowski
    2022

    Digital Government (DG) benchmarking is an academically vivid topic and, equally important, a tool with the potential to provide valuable insights to policymakers and public managers responsible for digital policies at the level of countries and international bodies. Alas, this potential remains largely untapped in the current DG benchmarking practice. In our study, we identify the reasons and propose a way of mitigating them. By referring to the managerial roots of benchmarking – to identify a unit’s problems and help it find a way toward performance improvements, we postulate to: 1) extract information coming from various measurement projects, 2) apply a process perspective to DG measurement – DG follows a series of value-generating transitions comprising a value chain, and 3) map the results to particular managerial or policy problems. We argue that the outcome, a comprehensive framework for country-level DG benchmarking built upon existing DG measurement instruments, offers a much higher diagnostic value than if such instruments are applied individually.

  • Biblioteka PG kontynuuje program digitalizacji i konserwacji. Kolejne tomy do renowacji z Programu Ministerstwa Edukacji i Nauki
    • Kamila Kokot-Kanikuła
    • Anna Sobolewska
    2022 Pismo PG

    Biblioteka Politechniki Gdańskiej ponownie otrzymała dofinansowanie na realizację projektu „Społeczna Odpowiedzialność Nauki". Celem projektu w ramach modułu „Wsparcie dla bibliotek naukowych” ogłoszonego przez Ministra Edukacji i Nauki jest konserwacja, digitalizacja i udostępnienie 16 woluminów z kolekcji zbiorów historycznych Biblioteki Politechniki Gdańskiej. Wartość projektu to 116 239,20 zł, a jego całkowity koszt wraz z wkładem finansowym Politechniki Gdańskiej to 126 472,00 zł.

  • Bioactive hybrid metal-organic framework (MOF)-based nanosensors for optical detection of recombinant SARS-CoV-2 spike antigen
    • Navid Rabiee
    • Yousef Fatahi
    • Sepideh Ahmadi
    • Nikzad Aabbariki
    • Amirhossein Ojaghi
    • Mohammad Rabiee
    • Fatemeh Radmanesh
    • Rassoul Dinarvand
    • Mojtaba Bagherzadeh
    • Ebrahim Mostafavi
    • Milad Ashrafizadeh
    • Pooyan Makvandi
    • Eder C. Lima
    • Mohammad Saeb
    2022 SCIENCE OF THE TOTAL ENVIRONMENT

    Fast, efficient, and accurate detection of SARS-CoV-2 spike antigen is pivotal to control the spread and reduce themortality of COVID-19. Nevertheless, the sensitivity of available nanobiosensors to detect recombinant SARS-CoV-2 spike antigen seems insufficient. As a proof-of-concept, MOF-5/CoNi2S4 is developed as a low-cost, safe, and bioactive hybrid nanostructure via the one-pot high-gravity protocol. Then, the porphyrin, H2TMP, was attached to the surface of the synthesized nanomaterial to increase the porosity for efficient detection of recombinant SARS-CoV-2 spike antigen. AFMresults approved roughness in different ranges, including 0.54 to 0.74 μm and 0.78 to≈0.80 μm, showing good physical interactions with the recombinant SARS-CoV-2 spike antigen. MTT assay was performed and compared to the conventional synthesis methods, including hydrothermal, solvothermal, and microwave-assisted methods. The synthesized nanodevices demonstrated above 88%relative cell viability after 24 h and even 48 h of treatment. Besides, the ability of the synthesized nanomaterials to detect the recombinant SARS-CoV-2 spike antigen was investigated, with a detection limit of 5 nM. The in-situ synthesized nanoplatforms exhibited low cytotoxicity, high biocompatibility, and appropriate tunability. The fabricated nanosystems seempromising for future surveys as potential platforms to be integrated into biosensors.

  • Biochemical, Structural Analysis, and Docking Studies of Spiropyrazoline Derivatives
    • Angelika Adamus-Grabicka
    • Mateusz Daśko
    • Pawel Hikisz
    • Joachim Kusz
    • Magdalena Malecka
    • Elzbieta Budzisz
    2022 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    In this study, we evaluated the antiproliferative potential, DNA damage, crystal struc‐ tures, and docking calculation of two spiropyrazoline derivatives. The main focus of the research was to evaluate the antiproliferative potential of synthesized compounds towards eight cancer cell lines. Compound I demonstrated promising antiproliferative properties, especially toward the HL60 cell line, for which IC50 was equal to 9.4 μM/L. The analysis of DNA damage by the comet assay showed that compound II caused DNA damage to tumor lineage cells to a greater extent than compound I. The level of damage to tumor cells of the HEC‐1‐A lineage was 23%. The determination of apoptotic and necrotic cell fractions by fluorescence microscopy indicated that cells treated with spiropyrazoline‐based analogues were entering the early phase of programmed cell death. Com‐ pounds I and II depolarized the mitochondrial membranes of cancer cells. Furthermore, we per‐ formed simple docking calculations, which indicated that the obtained compounds are able to bind to the PARP1 active site, at least theoretically (the free energy of binding values for compound I and II were −9.7 and 8.7 kcal mol−1, respectively). In silico studies of the influence of the studied com‐ pounds on PARP1 were confirmed in vitro with the use of eight cancer cell lines. The degradation of the PARP1 enzyme was observed, with compound I characterized by a higher protein degrada‐ tion activity.

  • Biocomposites from recycled resources as candidates for laboratory reference material to validate analytical tools used in organic compounds emissions investigation
    • Mariusz Marć
    • Małgorzata Rutkowska
    • Aleksander Hejna
    • Mateusz Barczewski
    2022 Pełny tekst BUILDING AND ENVIRONMENT

    A suitably chosen reference material should meet specific criteria like representing one of the compound classes most commonly occurring in indoor materials as well as having optimal long-term stability during storage and transport to its destination point and having a compact size. The described interdisciplinary pilot research was aimed to develop and characterize a polymer-based candidate for the laboratory reference material (LRM) of selected representatives of monoaromatic hydrocarbons (toluene and furfural) and terpenes emissions. Recycled, petroleum-based low-density polyethylene (LDPE) was applied as a matrix and was filled with plant-based wastes, such as apple pomace (AP), sunflower husks (SH), or yerba mate (YM) residues. The performance and suitability of the developed candidate for use as laboratory reference material was analyzed using FT-IR spectroscopy and differential scanning calorimetry (DSC). The migration potential of the representatives of monoaromatic hydrocarbons and terpenes emitted from the developed polymer material was assessed using the stationary emission microchamber system (μ-CTE 250). In the case of candidates for LRM with the addition of YM and AP, a clear relationship was observed between the samples seasoning time in the chamber and the total amount of VOCs released into the gaseous phase, including identified and determined representatives of terpenes. Furthermore, the existence of a clear relationship between the size (intensity) of the emission defined by the calculated summary parameters (TVOCs and sum of terpenes) and the seasoning/conditioning temperature of polymeric materials with bioadditives was observed.

  • Biodegradable Polymer Packaging Materials in Seawater Environment
    • Helena Janik
    • Justyna Kucińska-Lipka
    • Maciej Sienkiewicz
    • Alicja Kosakowska
    2022

    In this chapter, our interest is directed into dea/ocean/lakes biodegradable environment for polymer packaging materials from two different points of view.