2020 - Repozytorium publikacji - Politechnika Gdańska

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Uncertainty of mass flow measurement using centric and eccentric orifice for Reynolds number in the range 10,000 ≤ Re ≤ 20,000
- Anna Golijanek-Jędrzejczyk
- Andrzej Mrowiec
- Robert Hanus
- Marcin Zych
- Dariusz Świsulski
2020 Pełny tekst MEASUREMENT
The article analyses the impact of the Reynolds number on the estimated uncertainty of the mass flow rate measurement using an orifice plate. The objects of the research were two types of orifices: centric (ISA) and eccentric, with the diameter ratio β = 0.5. Studies were performed by Monte Carlo simulation and experiments for Reynolds numbers in the range 10,000 ≤ Re ≤ 20,000. The obtained results have shown that for both orifice types, the results obtained from the experiments and from the Monte Carlo simulation are similar. The nature of changes in the expanded uncertainty of the flow measurement is very similar for each type. For the both types of orifices, the value of the expanded uncertainty of the flow measurement increases linearly with the increasing Reynolds number.
Underfrequency Load Shedding: An Innovative Algorithm Based on Fuzzy Logic
- Robert Małkowski
- Janusz Nieznański
2020 Pełny tekst ENERGIES
In contemporary power systems, the load shedding schemes are typically based on disconnecting a pre-specified amount of load after the frequency drops below a predetermined value. The actual conditions at the time of disturbance may largely dier from the assumptions, which can lead to non-optimal or ineective operation of the load shedding scheme. For many years, increasing the eectiveness of the underfrequency load shedding (UFLS) schemes has been the subject of research around the world. Unfortunately, the proposed solutions often require costly technical resources and/or large amounts of real-time data monitoring. This paper puts forth an UFLS scheme characterized by increased eectiveness in the case of large disturbances and reduced disconnected power in the case of small and medium disturbances compared to the conventional load-shedding solutions. These advantages are achieved by replacing time-consuming consecutive load dropping with the simultaneous load dropping mechanism and by replacing ineective fixed-frequency activation thresholds independent of the state of the system with implicit adaptive thresholds based on fuzzy logic computations. The proposed algorithm does not require complex and costly technical solutions. The performance of the proposed scheme was validated using multivariate computer simulations. Selected test results are included in this paper.
Understanding the formation of metastable furan dication in collisions with ions
- Ewa Erdmann
- Suvasthika Indrajith
- Jacopo Chiarinelli
- Sergio Díaz-Tendero
- Nestor F. Aguirre
- Manuel Alcamí
- Alicja Domaracka
- Patrick Rousseau
- Bernd Alan Huber
- Paola Bolognesi
- Lorenzo Avaldi
- Marta Łabuda
2020 Pełny tekst Journal of Physics : Conference Series
This work relies on complementary theoretical and experimental studies of the processes induced by ion-furan collisions. Results of the Molecular Dynamics simulations and exploration of the energy profiles combined with coincidence mass spectrometry provide complete picture of the fragmentation of furan dication.
Underwater in situ local heat treatment by additional stitches for improving the weldability of steel
- Jacek Tomków
- Anna Janeczek
2020 Pełny tekst Applied Sciences-Basel
In this paper the influence of in situ local heat treatment performed by additional stitches on the weldability of high-strength low-alloy (HSLA) S355J2C+N steel was tested. The investigated steel is characterized by high susceptibility to cold cracking. It is necessary to find a method to improve the quality of welded joints. The local heat treatment was applied as an eect of bead-on plate welding made on the face of a Tekken test joint. The specimens were made by the use of covered electrodes in the water environment. For testing weldability, Tekken test specimens were made. Then, the dierent number of the pad welds with dierent overlapping were laid on the face of the tested welds. Non-destructive (NDT) visual and penetrant tests were undertaken. During the NDT, imperfections like shape mistakes and spatters were found. Then, metallographic macro- and microscopic testing were performed. The macroscopic observations proved that water environment can generate imperfections like cracking and pores. However, for specimens with additional stitches the number of imperfections decreased. Microscopic tests proved that the proposed technique aected the structure of the heat-aected zone (HAZ). The specimens without the application of additional stitches are characterized by brittle bainitic and martensitic structure. Specimens, in which the additional stitches were applied, contain tempered martensite, fine ferrite and fine pearlite in their HAZ. It was also observed that the number of cracks decreased for in situ local heat-treatment specimens. The final step was Vickers HV10 hardness measurement. These measurements confirmed previous results. The heat from additional stitches aected the steel by significantly decreasing the hardness by 80–100 HV10. The results of experiments showed that the heat from pad welds provided microstructural changes in heat-aected zones and a decrease in the susceptibility to cold cracking, which results in improvement in the weldability of HSLA steel in wet welding conditions.
Underwater Local Cavity Welding of S460N Steel
- Jacek Tomków
- Anna Janeczek
- Grzegorz Rogalski
- Adrian Wolski
2020 Pełny tekst Materials
In this paper, a comparison of the mechanical properties of high-strength low-alloy S460Nsteel welded joints is presented. The welded joints were made by the gas metal arc welding (GMAW)process in the air environment and water, by the local cavity welding method. Welded joints were testedfollowing the EN ISO 15614-1:2017 standard. After welding, the non-destructive—visual, penetrant,radiographic, and ultrasonic (phased array) tests were performed. In the next step, the destructive tests,as static tensile-, bending-, impact- metallographic (macroscopic and microscopic) tests, and VickersHV10 measurements were made. The influence of weld porosity on the mechanical properties of thetested joints was also assessed. The performed tests showed that the tensile strength of the jointsmanufactured in water (567 MPa) could be similar to the air welded joint (570 MPa). The standarddeviations from the measurements were—47 MPa in water and 33 MPa in the air. However, it was alsostated that in the case of a complex state of stress, for example, bending, torsional and tensile stresses,the welding imperfections (e.g., pores) significantly decrease the properties of the welded joint.In areas characterized by porosity the tensile strength decreased to 503 MPa. Significant differenceswere observed for bending tests. During the bending of the underwater welded joint, a smallerbending angle broke the specimen than was the case during the air welded joint bending. Also,the toughness and hardness of joints obtained in both environments were different. The minimumtoughness for specimens welded in water was 49 J (in the area characterized by high porosity) and inthe air it was 125 J (with a standard deviation of 23 J). The hardness in the heat-affected zone (HAZ)for the underwater joint in the non-tempered area was above 400 HV10 (with a standard deviation of37 HV10) and for the air joint below 300 HV10 (with a standard deviation of 17 HV10). The performedinvestigations showed the behavior of S460N steel, which is characterized by a high value of carbonequivalent (CeIIW) 0.464%, during local cavity welding.
Underwater Navigation Ssystem Based on Doppler Shift – Measurements and Error Estimations
- Zawisza Ostrowski
- Roman Salamon
- Iwona Kochańska
- Jacek Marszal
2020 Pełny tekst Polish Maritime Research
A new acoustic navigation system was developed to determine the position and speed of moving underwater objects such as divers and underwater vehicles. The path of an object and its speed were determined by the Doppler shifts of acoustic signals emitted by a transmitter placed on the object and received by four hydrophones installed at the periphery of the monitored body of water. The position and speed measurements were affected by errors mainly caused by acoustic reflections (returns) from the water body boundaries and surface reverberations. This paper discusses the source of the disturbances with the results of a simulation test and experimental measurements. It was demonstrated that the magnitude of the errors could be acceptable in most of the potential applications of the acoustic navigation system.
Unidirectional DC/DC Converter with Voltage Inverter for Fast Charging of Electric Vehicle Batteries
- Jerzy, Ryszard Szymanski
- Marta Żurek-mortka
- Daniel Wojciechowski
- Nikolai Poliakov
2020 Pełny tekst ENERGIES
The paper proposes the adaptation of the industrial plant’s power network to supply electric vehicle (EV) fast-charging converters (above 300 kW) using renewable energy sources (RESs). A 600 V DC microgrid was used to supply energy from RESs for the needs of variable speed motor drives and charging of EV batteries. It has been shown that it is possible to support the supply of drive voltage frequency converters (VFCs) and charging of EV batteries converters with renewable energy from a 600 V DC microgrid, which improves the power quality indicators in the power system. The possibility of implementing the fast EV batteries charging station to the industrial plant’s power system in such a way that the system energy demand is not increased has also been shown. The EV battery charging station using the drive converter has been presented, as well as the results of simulation and laboratory tests of the proposed solution.
Unieuro
- Luciano Segreto
2020
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Unifying Aspects of Generalized Calculus
- Marek Czachor
2020 Pełny tekst ENTROPY
Non-Newtonian calculus naturally unifies various ideas that have occurred over the years in the field of generalized thermostatistics, or in the borderland between classical and quantum information theory. The formalism, being very general, is as simple as the calculus we know from undergraduate courses of mathematics. Its theoretical potential is huge, and yet it remains unknown or unappreciated.
Unlocking creativity with new technologies
- Norbert Piotrowski
2020 World Aerosols. The Voice of the Aerosol Industry
Artificial intelligence, augmented and virtual reality, Internet of Things and digital twins are just a few concepts related to the fourth industrial revolution that is happening right before our eyes. The key question asked by managers in the aerosol sector recently is: what does all this new technology mean to me?
Untargeted Lipidomics Analysis of the Cyanobacterium Synechocystis sp. PCC 6803: Lipid Composition Variation in Response to Alternative Cultivation Setups and to Gene Deletion
- Weronika Hewelt-Belka
- Agata Kot-Wasik
- Paula Tamagnini
- Paulo Oliveira
2020 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Cyanobacteria play an important role in several ecological environments, and they are widely accepted to be the ancestors of chloroplasts in modern plants and green algae. Cyanobacteria have become attractive models for metabolic engineering, with the goal of exploring them as microbial cell factories. However, the study of cyanobacterial lipids’ composition and variation, and the assessment of the lipids’ functional and structural roles have been largely overlooked. Here, we aimed at expanding the cyanobacterial lipidomic analytical pipeline by using an untargeted lipidomics approach. Thus, the lipid composition variation of the model cyanobacterium Synechocystis sp. PCC 6803 was investigated in response to both alternative cultivation setups and gene deletion. This approach allowed for detecting differences in total lipid content, alterations in fatty-acid unsaturation level, and adjustments of specific lipid species among the identified lipid classes. The employed method also revealed that the cultivation setup tested in this work induced a deeper alteration of the cyanobacterial cell lipidome than the deletion of a gene that results in a dramatic increase in the release of lipid-rich outer membrane vesicles. This study further highlights how growth conditions must be carefully selected when cyanobacteria are to be engineered and/or scaled-up for lipid or fatty acids production.
Upper Limb Bionic Orthoses: General Overview and Forecasting Changes
- Gustaw Rzyman
- Jacek Szkopek
- Grzegorz Redlarski
- Aleksander Pałkowski
2020 Pełny tekst Applied Sciences-Basel
Using robotics in modern medicine is slowly becoming a common practice. However, there are still important life science fields which are currently devoid of such advanced technology. A noteworthy example of a life sciences field which would benefit from process automation and advanced robotic technology is rehabilitation of the upper limb with the use of an orthosis. Here, we present the state-of-the-art and prospects for development of mechanical design, actuator technology, control systems, sensor systems, and machine learning methods in rehabilitation engineering. Moreover, current technical solutions, as well as forecasts on improvement, for exoskeletons are presented and reviewed. The overview presented might be the cornerstone for future research on advanced rehabilitation engineering technology, such as an upper limb bionic orthosis.
Uproszczone metody obliczania cylindrycznych silosów z blachy falistej i słupów cienkościennych
- Karol Rejowski
- Piotr Iwicki
- Andrzej Tejchman-Konarzewski
2020 Pełny tekst Inżynieria i Budownictwo
Celem artykułu jest wyznaczenie nośności wyboczeniowej trzech silosów wykonanych z falistej blachy ze sfałdowaniem w kierunku obwodowym, wzmocnionych słupami pionowymi stosując modele MES całych konstrukcji i ich segmentów oraz porównanie obliczonej nośności wyboczeniowej z Eurokodem 3, poprawkami do Eurokodu 3 i metodą zaproponowaną w literaturze. Nowym elementem analizowanym w pracy jest porównanie różnych metod analitycznych z wynikami analiz MES oraz procedurami normowymi. W artykule zweryfikowano także metodę opisaną w literaturze dla silosów, w których słupy miały zmienny przekrój poprzeczny, dopasowany do wypadkowych obciążeń w słupach.
Urban regeneration in urban functional areas in Poland as an instrument of implementation of the EU Cohesion Policy
- Dorota Kamrowska-Załuska
- Hanna Obracht-Prondzyńska
2020 GROWTH AND CHANGE
This study examines the role of urban regeneration policies in planning and governance within urban functional areas (UFAs) in Poland, in the context of the EU Cohesion Policy (CP). The empirical part of this study is based on comparing the approaches adopted in two Polish regions: Pomerania and Silesia. We describe the first successes but also the bottlenecks of the process, from negotiations and programming up to the implementation of the first tranche of integrated projects. We consider the factors that strengthen planning and governance within UFAs, while simultaneously influencing the local development, and territorial impacts of the EU Cohesion Policy in the given regions. This study is based on interviews with national, regional, and local actors. It defines the role of urban regeneration policies in shaping local socio‐economic and spatial development in these regions and identifies the conditions required for the implementation of urban regeneration in functional areas. We also draw lessons for the future CP programming period from the experience of Polish regions, among the main beneficiaries of the EU Cohesion Policy. By evaluating the influence of Cohesion Policy at different government levels, our study may influence the discourse on its future, particularly in the context of strengthening the cooperation and multilevel governance.
Urban Vegetation in Air Quality Management: A Review and Policy Framework
- Joanna Badach
- Małgorzata Dymnicka
- Andrzej Baranowski
2020 Pełny tekst Sustainability
Recent episodes of high air pollution concentration levels in many Polish cities indicate the urgent need for policy change and for the integration of various aspects of urban development into a common platform for local air quality management. In this article, the focus was placed on the prospects of improving urban air quality through proper design and protection of vegetation systems within local spatial planning strategies. Recent studies regarding the mitigation of air pollution by urban greenery due to deposition and aerodynamic effects were reviewed, with special attention given to the design guidelines resulting from these studies and their applicability in the process of urban planning. The conclusions drawn from the review were used to conduct three case studies: in Gdańsk, Warsaw, and Poznan, Poland. The existing local urban planning regulations for the management of urban greenery were critically evaluated in relation to the findings of the review. The results indicate that the current knowledge regarding the improvement of urban air quality by vegetation is not applied in the process of urban planning to a sufficient degree. Some recommendations for alternative provisions were discussed.
Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
- Magdalena Miodynska
- Alicja Mikolajczyk
- Beata Bajorowicz
- Julia Zwara
- Tomasz Klimczuk
- Wojciech Lisowski
- Grzegorz Trykowski
- Henry P. Pinto
- Adriana Zaleska-Medynska
2020 Pełny tekst APPLIED CATALYSIS B-ENVIRONMENTAL
The formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at Er and Yb contents of 10 mol%. Specifically, a hydrogen productivity of 1576.7 μmol gcat −1 is achieved after 20-h irradiation for TiO2 decorated by 10 mol% Yb-doped Bi2S3 QDs. Theoretical calculations show that the introduction of defects into the Bi2S3 lattice through Er/Yb doping promotes the creation of new energy levels and facilitates the transport of photogenerated charges during photocatalysis.
Usability of mobile applications: a systematic literature study
- Paweł Weichbroth
2020 Pełny tekst IEEE Access
Since the release of the first mobile devices, the usability of on-board applications has been the concern not only of software vendors but hardware manufacturers as well. The academia community later willingly joined the discussion on usability in terms of theory and empirical measurement, having experience and knowledge in desktop settings. At first sight, such a background should guarantee a solid foundation to conduct research on software usability in a new setting. However, a preliminary study on the subject matter revealed methodological disorder in contemporary literature. As a matter of fact, a need emerged to review existing usability definitions, attributes and measures to recognize all associated aspects. In order to fill this void, we conducted a systematic literature review on usability studies indexed by the Scopus database and devoted to mobile applications. The input volume covers 790 documents from 2001 to 2018. The data analysis shows that the ISO 9241–11 usability definition has been adopted in an unchanged form and popularized as the standard by the HCI community. Secondly, in total, 75 attributes were identified and analysed. The most frequent are efficiency (70%), satisfaction (66%) and effectiveness (58%), which directly originate from the above definition. Subsequently, the less frequent are learnability (45%), memorability (23%), cognitive load (19%) and errors (17%). The last two concern simplicity (13%) and ease of use (9%). Thirdly, in the evaluation of usability, controlled observation and surveys are two major research methods applied, while eye-tracking, thinking aloud and interview are hardly used and serve as complementary to collect additional data. Moreover, usability evaluations are often confused with user experience dimensions, covering not only application quality characteristics, but also user beliefs, emotions and preferences. All these results indicate the need for further research on the usability of mobile applications, aiming to establish a consensus in the theory and practice among all interested parties.
Use of pyridinium and pyrrolidinium ionic liquids for removal of toluene from gas streams
- Iwona Cichowska-Kopczyńska
- Robert Aranowski
2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS
Separation of toluene from a toluene/N2 gas mixture using supported liquid membranes based on a series of pyridinium (1-butylpyridinium- bis(trifluoromethylsulfonyl)imide - [C4Py][Tf2N], 1-hexylpyridinium trifluoromethanesulfone [C6Py][Tf2N]) and pyrrolidinium (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C4Pyrr][Tf2N], 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C6Pyrr][Tf2N], 1-butyl-1-methylpyrrolidinium trifluoromethanesulfone - [C4Pyrr][TfO]) ionic liquids (ILs) was studied over a wide range of temperatures. The toluene permeability and selectivity of separation was investigated in terms of cation and anion type. It was found that both pyridinium and pyrrolidinium ILs show high toluene permeability, up to 2034 barrers, with satisfying separation selectivity. An analysis of two key factors that have an influence on this process, that is diffusion in a form of resistance resulting from the viscosity of membrane liquid and the solubility expressed by the partition coefficient, was made.
Using Fast Frequency Hopping Technique to Improve Reliability of Underwater Communication System
- Jan Schmidt
2020 Pełny tekst Applied Sciences-Basel
Acoustic underwater communication systems designed to work reliably in shallow coastal waters must overcome major limitations such as multipath propagation and the Doppler effect. These restrictions are the reason for the complexity of receivers being built, whose task is to decode a symbol on the basis of the received signal. Additional complications are caused by the low propagation speed of the acoustic wave in the water and the relatively narrow bandwidth. Despite the continuous development of communication systems using coherent modulations, they are still not as reliable as is desirable for reliable data transmission applications. This article presents an acoustic underwater communication system that uses one of the varieties of the spread spectrum technique i.e., the fast frequency hopping technique (FFH). This technique takes advantage of binary frequency-shift keying (BFSK) with an incoherent detection method to ensure the implementation of a system whose main priority is reliable data transmission and secondary priority is the transmission rate. The compromised choice of parameters consisted of the selection between the narrow band of the hydroacoustic transducer and the maximum number of carrier frequency hops, which results from the need to take into account the effects of the Doppler effect. In turn, the number of hops and the symbol duration were selected adequately for the occurrence of multipath propagations of an acoustic wave. In addition, this article describes experimental communication tests carried out using a laboratory model of the FFH-BFSK data transmission system in the shallow water environment of Lake Wdzydze/Poland. The test results obtained for three channels of different lengths are discussed.
Using Moodle as a Solution to Interdisciplinary E-collaboration Issues
- Ewa Kozłowska
2020 Pełny tekst International Journal of Research in E-learning
Rapid technological development in recent years has contributed to numerous changes in many areas of life, including education and communication. Establishing interdisciplinary collaboration brings many benefits, however, it is often associated with numerous problems and inconveniences, as well as the need of constant improvement, lifelong learning, professional development (CPD) and finding an effective way of information transferring. Living in a constant rush makes logical order of information transferring become a key aspect, as more and more operations are being done chaotically using multiple online tools. Although collaboration happens to be complicated even for colleagues specializing in different aspects of the same profession, establishing cooperation between specific groups of interdisciplinary specialists, such as engineers and physicians, has a significant impact on modern diagnostics and medical treatment development. Based on some selected case studies investigated at Gdańsk University of Technology and Medical University of Gdańsk, supported by an overview of the available education and collaboration tools, a solution based on the Moodle LMS platform has been proposed, implemented, and analyzed.