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Gdańsk University of Technology

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  • Integracja bezprzewodowych heterogenicznych sieci IP dla poprawy efektywności transmisji danych na morzu
    • Michał Hoeft
    2023 Full text

    Wraz ze wzrostem istotności środowiska morskiego w naszym codziennym życiu np. w postaci zwiększonego wolumenu transportu realizowanego drogą morską. czy zintensyfikowanych prac dotyczących obserwacji i monitoringu środowiska morskiego, wzrasta również potrzeba opracowania efektywnych systemów komunikacyjnych dedykowanych dla tego środowiska. Heterogeniczne systemy łączności bezprzewodowej integrowane na poziomie warstwy sieciowej mogą przynieść istotne korzyści w postaci łatwości wdrożenia, elastyczności, czy zwiększonej skalowalności płynących z ich zastosowania w rozwiązaniach komunikacji morskiej. Celem prac opisanych w rozprawie jest opracowanie i przebadanie mechanizmów integracji heterogenicznych systemów łączności wykorzystywanych w komunikacji na morzu, pozwalających na poprawę efektywności tej komunikacji. Teza pracy doktorskiej jest następująca „Integracja heterogenicznych systemów transmisji z wykorzystaniem miękkiego przełączania oraz kodowania sieciowego poprawia efektywność transmisji danych w bezprzewodowych sieciach IP na morzu". Aby udowodnić tę tezę, autor zaproponował rozwiązanie miękkiego przełączania oraz mechanizmy wyboru łącza wspomagane głębokimi sieciami neuronowymi. Dodatkowo przedstawione zostały możliwości zastosowania kodowania sieciowego w zaprezentowanej architekturze systemu obsługi mobilności oraz wskazane zostały korzyści z zastosowania zaproponowanych algorytmów: heurystycznego i uczenia ze wzmocnieniem.

  • Integrated model for the fast assessment of flood volume: Modelling – management, uncertainty and sensitivity analysis
    • Bartosz Szeląg
    • Przemysław Kowal
    • Adam Kiczko
    • Anita Białek
    • Grzegorz Wałek
    • Dariusz Majerek
    • Piotr Siwicki
    • Francesco Fatone
    • Grzegorz Boczkaj
    2023 JOURNAL OF HYDROLOGY

    The specific flood volume is an important criterion for assessing the performance of sewage networks. It has been shown that its value is greatly influenced by the layout of the sewers in the catchment area, which is usually expressed by a fractal dimension. Currently, only mechanistic models (such as SWMM) enable the determination of the impact of the layout of the sewers on flooding volume, but they require additional and robust calculations. In the presented study an integrated tool has been proposed that includes: a flooding volume simulator based on rainfall data, catchment and sewage network characteristics, sewers layout expressed by fractal dimension. A logistic model can be applied for fast flooding volume estimation as an alternative approach to SWMM, design and upgrade sewer layout even with limited access to data (spatial planning, architectural concepts, etc.). Using the random forest (RF) method, a likelihood function simulator was developed, which enabled the analysis of interactions and optimal selection of combinations of SWMM model parameters for calibration. It has been shown that the higher the fractal dimension and retention coefficient (the ratio of surface to sewer retention), the greater the influence of SWMM parameters on the specific flood volume.

  • Integrating modelling, simulation and data management tools to create a planning support system for the improvement of air quality by urban planning solutions
    • Joanna Badach
    2023

    The urbanization pressure requires urban planners, designers, and policy makers to be more responsive to the challenges related to improving the quality of the urban environment and the living conditions of the inhabitants. One of the many environmental issues that need to be taken into account is urban air pollution. As the process of urban ventilation and air pollution dis-persion is significantly affected by the urban layout, the planning and design practice offers some solutions for urban air quality improvement. The paper outlines the most important planning implications for the integrated manage-ment of urban ventilation and air quality. The results indicate that the integra-tion of various scale-adaptive modelling, simulation, and data management tools is necessary for the comprehensive assessment of the impact of spatial solutions on urban air quality and the formulation of planning outlines. A case study of the city of Warsaw, Poland, was demonstrated in the paper.

  • Integration of the sulfate reduction and anammox processes for enhancing sustainable nitrogen removal in granular sludge reactors
    • Dominika Derwis
    • Joanna Majtacz
    • Przemysław Kowal
    • Hussein Al-Hazmi
    • Jun Zhai
    • Slawomir Ciesielski
    • Grzegorz Piechota
    • Jacek Mąkinia
    2023 BIORESOURCE TECHNOLOGY

    The Anammox and Sulfate Reduction Ammonium Oxidation processes were compared in two granular sequencing batch reactors operated for 160 days under anammox conditions. It was hypothesized that increasing the concentration of SO42− may positively influence the rate of N removal under anaerobic conditions and it was tested whether SO42− reduction and anammox occur independently or are related to each other. The cooperation of N-S cycles by increasing the concentration of influent SO42− to 952 mg S/L in the second reactor, a higher ammonium utilization rate and sulfate utilization rate was achieved compared to the first reactor, i.e., 2.1-fold and 15-fold, respectively. Nitrosomonas played the dominant role in the N metabolism, while Thauera – in the S metabolism. This study highlights the benefits of linking the N-S cycles as an effective approach for the treatment of NH4+ and SO42− – rich wastewater, including lower substrate removal cost and reduced energy consumption.

  • Interakcje układów przesyłowych prądu stałego ze szczególnym uwzględnieniem pracy wyspowej systemu elektroenergetycznego
    • Michał Kosmecki
    2023 Full text

    Układ przesyłowy prądu stałego to złożona pod względem technicznym struktura, której poprawne funkcjonowanie jest w decydującym stopniu zależne od niezawodnego i niezakłóconego działania układów sterownia. W przypadku pracy dwóch lub więcej takich układów przyłączonych blisko siebie nieuniknione jest wzajemne oddziaływanie (interakcja) tych układów. Celem rozprawy jest identyfikacja i analiza kluczowych elementów interakcji dwóch układów przesyłowych prądu stałego pracujących w warunkach pracy wyspowej, co zazwyczaj oznacza niewielką moc zwarciową oraz inercję systemu elektroenergetycznego. Postawiona przez autora teza w brzmieniu „Możliwa jest identyfikacja oraz analiza jakościowa i ilościowa wpływu aktywnych elementów regulacyjnych oraz pasywnych elementów układów HVDC i sieci AC w różnych warunkach pracy systemu elektroenergetycznego wyspy na charakter i zakres interakcji między układem LCC HVDC i VSC HVDC poprzez opracowanie i badania zlinearyzowanego modelu pracy wspólnej obu układów w szczególności wykorzystujące elementy analizy modalnej” wymagała doboru metod matematycznych oraz opracowania i zweryfikowania modeli symulacyjnych układów HVDC.

  • Intermolecular Hydrogen Bonding Directed by Aryl–Perfluoroaryl π–π Stacking Interactions
    • Jan Alfuth
    • Katarzyna Kazimierczuk
    • Tadeusz Połoński
    • Teresa Olszewska
    2023 Full text CRYSTAL GROWTH & DESIGN

    The crystal structures of five compounds capable of forming self-complementary hydrogen bonds but crystallizing as catemers or creating more complex crystal structures were compared with their complexes prepared by cocrystallization with perfluoroaryl compounds. The results of X-ray diffraction revealed that in all the cases the π–π stacking interactions caused reorganization of hydrogen bonds and induced creation of the expected self-complementary hydrogen bond dimeric motifs. The results point to the potential of aryl–perfluoroaryl interactions for the control of molecular self-assembly of aromatic compounds able to form hydrogen bonds. Also, the electrostatic potential (ESP) surfaces were investigated in terms of intermolecular interactions in the studied cocrystals. The values of the locally most negative and most positive ESP confirmed the best donor and acceptor sites for hydrogen bonding and other contacts.

  • Internacjonalizacja przedsiębiorstw na obszarze Euroazjatyckiej Unii Gospodarczej na przykładzie Kazachstanu
    • Inna Sobaszek
    2023 Full text

    Autorka podjęła badania nad wpływem Euroazjatyckiej Unii Gospodarczej (EUG) na internacjonalizację kazachskich przedsiębiorstw, motywowana aktualnością tematu i brakiem kompleksowych badań w tej dziedzinie. Celem pracy jest analiza wpływu EUG na proces internacjonalizacji firm w Kazachstanie. Rozprawa składa się z czterech rozdziałów, z których pierwsze trzy mają charakter teoretyczny, a czwarty jest empiryczny. W rozdziałach teoretycznych omówiono internacjonalizację przedsiębiorstw, czynniki umiędzynarodowienia i rolę otoczenia w tym procesie, a także integrację ekonomiczną i charakterystykę EUG, szczególnie z perspektywy Kazachstanu. Czwarty rozdział przedstawia wyniki badań empirycznych przeprowadzonych w Kazachstanie, analizując poziom internacjonalizacji firm, metody umiędzynarodowienia oraz kierunki ekspansji międzynarodowej. W konkluzji autorka odpowiada na hipotezy badawcze i sugeruje kierunki dalszych badań.

  • International Conference on Diagnostics of Processes and Systems 2022
    • Zdzisław Kowalczuk
    2023 Pomiary Automatyka Robotyka

    Wydarzenie stanowiło 15 ogniwo cyklu organizowanego od 1996 roku, naprzemiennie przez Politechnikę Warszawską, Uniwersytet Zielonogórski oraz Politechnikę Gdańską. Tegoroczna edycja konferencji została objęta patronatem JM Rektora Politechniki Gdańskiej, prof. Krzysztofa Wilde, Komitetu Automatyki i Robotyki Polskiej Akademii Nauk, Towarzystwa Konsultantów Polskich (FSNT-NOT) oraz Polskiego Stowarzyszenia Pomiarów Automatyki i Robotyki POLSPAR, narodowego członka (NMO) Międzynarodowego Stowarzyszenia Automatyki IFAC.

  • Interpretable deep learning approach for classification of breast cancer - a comparative analysis of multiple instance learning models
    • Jakub Buler
    • Rafał Buler
    • Maciej Bobowicz
    • Maria Ferlin
    • Marlena Rygusik
    • Arkadiusz Kwasigroch
    • Michał Grochowski
    2023

    Breast cancer is the most frequent female cancer. Its early diagnosis increases the chances of a complete cure for the patient. Suitably designed deep learning algorithms can be an excellent tool for quick screening analysis and support radiologists and oncologists in diagnosing breast cancer.The design of a deep learning-based system for automated breast cancer diagnosis is not easy due to the lack of annotated data, especially at pixel level, the large size of the images with relatively small cancer lesion sizes and class imbalance, a wide diversity of cancerous lesions, a variety of breasts, both in size and density, make the training of the neural models challenging. Moreover, clinicians are often concerned about using these black-box models because of the lack of transparency in their inference. To address these issues, we propose an approach taking advantage of Multiple Instance Learning (MIL), supported by attention mechanisms. We researched Attention-based MIL (AMIL), Gated AMIL (GAMIL), Dual Stream MIL (DSMIL) and CLustering-constrained AMIL (CLAM) models trained in a weakly-supervised manner and compared them with a common model in image classification tasks, ResNet18.The approach described in this paper is multimodal and combines two mammographic projections (CC and MLO) in the training process. The developed neural system achieved high classification efficiency. Furthermore, exploiting the generated attentional maps allowed the localisation of cancerous lesions, thus increasing the interpretability of the algorithm. Thanks to this mechanism, we were also able to detect artifacts in the analyzed database, difficult to spot but drastically skewing the algorithm’s performance.

  • ‘Interspaces of the house | contextualized. our homes about ourselves’ cykl obrazów [w ramach:] międzynarodowa wystawa zbiorowa | ekspozycja hybrydowa Muestra de Arte Universitario - International MAU-I 2023, 'Interconexiones culturales: mirar cómo miras’
    • Agnieszka Kurkowska
    2023

    interprzestrzenie domu: skontekstowane. nasze domy o nas samych W obrazie domu rodzinnego, z którym się utożsamiamy widzimy samych siebie. Tak też poznajemy naszych sąsiadów i ludzi z dalszych kręgów kulturowych. Sposób zamieszkiwania, tworzone schronienia współtworzą nasz wizerunek. Migracje, przemieszczenia, przenoszenie kulturowego wzorca domu i jego spasowywanie z realiami zastanymi tworzy przestrzeń innowacyjnych rozwiązań. Adaptowalność, inspiracja innością i nieznanym stanowi wyzwanie. Trudność koniecznej zmiany wyzwala energię krytyczną. Powstanie domu łagodzi lęk. Oswaja nowe przestrzenie, jest wejściem w nową kulturę. Posiadanie domu pomaga wzrastać w nowym . Przestrzeń lasu zaanektowana na potrzeby zamieszkiwania swobodnie przepływa. Poprzez wgląd, refleksję, przebywanie, czas namysłu wywołuje marzenia o domach wpasowanych w miejsce. Interkulturowych. Jak my współcześnie.

  • Intracranial hemorrhage detection in 3D computed tomography images using a bi-directional long short-term memory network-based modified genetic algorithm
    • Jewel Sengupta
    • Robertas Alzbutas
    • Przemysław Falkowski-Gilski
    • Bożena Falkowska-Gilska
    2023 Full text Frontiers in Neuroscience

    Introduction: Intracranial hemorrhage detection in 3D Computed Tomography (CT) brain images has gained more attention in the research community. The major issue to deal with the 3D CT brain images is scarce and hard to obtain the labelled data with better recognition results. Methods: To overcome the aforementioned problem, a new model has been implemented in this research manuscript. After acquiring the images from the Radiological Society of North America (RSNA) 2019 database, the region of interest (RoI) was segmented by employing Otsu’s thresholding method. Then, feature extraction was performed utilizing Tamura features: directionality, contrast, coarseness, and Gradient Local Ternary Pattern (GLTP) descriptors to extract vectors from the segmented RoI regions. The extracted vectors were dimensionally reduced by proposing a modified genetic algorithm, where the infinite feature selection technique was incorporated with the conventional genetic algorithm to further reduce the redundancy within the regularized vectors. The selected optimal vectors were finally fed to the Bi-directional Long Short Term Memory (Bi-LSTM) network to classify intracranial hemorrhage sub-types, such as subdural, intraparenchymal, subarachnoid, epidural, and intraventricular. Results: The experimental investigation demonstrated that the Bi-LSTM based modified genetic algorithm obtained 99.40% sensitivity, 99.80% accuracy, and 99.48% specificity, which are higher compared to the existing machine learning models: Naïve Bayes, Random Forest, Support Vector Machine (SVM), Recurrent Neural Network (RNN), and Long Short-Term Memory (LSTM) network.

  • Intramolecular Proton Transfer in the Radical Anion of Cytidine Monophosphate Sheds Light on the Sensitivities of Dry vs Wet DNA to Electron Attachment-Induced Damage
    • Lidia Chomicz-Mańka
    • Anna Czaja
    • Karina Falkiewicz
    • Magdalena Zdrowowicz
    • Karol Biernacki
    • Sebastian Demkowicz
    • Farhad Izadi
    • Eugene Arthur-Baidoo
    • Stephan Denifl
    • Zhaoguo Zhu
    • Burak Ahmet Tufekci
    • Rachel Harris
    • Kit H. Bowen
    • Janusz Rak
    2023 Full text JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

    Single-strand breaks (SSBs) induced via electron attachment were previously observed in dry DNA under ultrahigh vacuum (UHV), while hydrated electrons were found not able to induce this DNA damage in an aqueous solution. To explain these findings, crossed electron-molecular beam (CEMB) and anion photoelectron spectroscopy (aPES) experiments coupled to density functional theory (DFT) modeling were used to demonstrate the fundamental importance of proton transfer (PT) in radical anions formed via electron attachment. Three molecular systems were investigated: 5′-monophosphate of 2′-deoxycytidine (dCMPH), where PT in the electron adduct is feasible, and two ethylated derivatives, 5′-diethylphosphate and 3′,5′-tetraethyldiphosphate of 2′-deoxycytidine, where PT is blocked due to substitution of labile protons with the ethyl residues. CEMB and aPES experiments confirmed the cleavage of the C3′/C5′–O bond as the main dissociation channel related to electron attachment in the ethylated derivatives. In the case of dCMPH, however, electron attachment (in the aPES experiments) yielded its parent (intact) radical anion, dCMPH–, suggesting that its dissociation was inhibited. The aPES-measured vertical detachment energy of the dCMPH– was found to be 3.27 eV, which agreed with its B3LYP/6-31++G(d,p)-calculated value and implied that electron-induced proton transfer (EIPT) had occurred during electron attachment to the dCMPH model nucleotide. In other words, EIPT, subduing dissociation, appeared to be somewhat protective against SSB. While EIPT is facilitated in solution compared to the dry environment, the above findings are consistent with the stability of DNA against hydrated electron-induced SSB in solution versus free electron-induced SSB formation in dry DNA.

  • Intra-subject class-incremental deep learning approach for EEG-based imagined speech recognition
    • Jesys Garcia Salinas
    • Alejandro A. Torres-García
    • Carlos A. Reyes-Garćia
    • Luis Villaseñor-Pineda
    2023 Biomedical Signal Processing and Control

    Brain–computer interfaces (BCIs) aim to decode brain signals and transform them into commands for device operation. The present study aimed to decode the brain activity during imagined speech. The BCI must identify imagined words within a given vocabulary and thus perform the requested action. A possible scenario when using this approach is the gradual addition of new words to the vocabulary using incremental learning methods. An issue with incremental learning methods is degradation of the decoding capacity of the original model when new classes are added. In this study, a class-incremental neural network method is proposed to increase the vocabulary of imagined speech. The results indicate a stable model that did not degenerate when a new word was integrated. The proposed method allows for the inclusion of newly imagined words without a significant loss of total accuracy for the two datasets.

  • Introducing a Computational Method to Retrofit Damaged Buildings under Seismic Mainshock-Aftershock Sequence
    • Farzin Kazemi
    • Neda Asgarkhani
    • Ahmed Manguri
    • Natalia Lasowicz
    • Robert Jankowski
    2023 Full text

    Retrofitting damaged buildings is a challenge for engineers, since commercial software does not have the ability to consider the local damages and deformed shape of a building resulting from the mainshock record of an earthquake before applying the aftershock record. In this research, a computational method for retrofitting of damaged buildings under seismic mainshock-aftershock sequences is proposed, and proposed computational strategy is developed using Tcl programming code in OpenSees and MATLAB. Since the developed programming code has the ability of conducting nonlinear dynamic analysis (e.g. Incremental Dynamic Analysis (IDA)), different types of steel and reinforced concrete structures, assuming different intensity measures and engineering demands, can be on the benefit of this study. To present the ability of method, the 4-Story and 6-Story damaged steel structures were selected. Then, the linear Viscous Dampers (VDs) are used for retrofitting of the damaged structures, and IDAs were performed under aftershock records. The results showed that the proposed method and computational program could improve the seismic performance level of damaged structures subjected to the mainshockaftershock sequences. In addition, the damaged floor level of the building is recognized by programming code and can be effectively considered for local retrofit schemes.

  • INTRODUCING GREENERY INTO A BUILDING BASED ON ITS IMPACT ON HUMAN WELLBEING - REVIEW OF THEORIES AND METHODS IN ARCHITECTURE
    • Katarzyna Zielonko-Jung
    • Anna Wróblewska
    2023 Full text Architecture Civil Engineering Environment

    Greenery around and within buildings is an integral part of architectural space. Although science is providing more and more knowledge about the impact of greenery on human well-being, there is still a lack of guidelines on how to apply this knowledge in architectural design. The purpose of this review article is to prepare the ground for further research on how to support architectural design in integrating greenery as a co-creative element of human living space. Existing review texts are diverse and scattered across various scientific fields, describing different goals, approaches, and research methods. Therefore, this review initially concentrates on examining the broad topic of perception in architecture, highlighting significant theories and methods. The next step involves analysis of the state of research specifically focused on wellbeing and perception of greenery in the built environment. Important criteria for this analysis include the potential for obtaining objective, quantitative results. Finally, the available research methods are categorized, considering their stages of development. Those that seem most relevant to the field of architecture have been identified.

  • Introduction to the ONDM 2022 special issue
    • Jarosław Turkiewicz
    • Teresa Gomes
    • Mirosław Klinkowski
    • Jacek Rak
    • Massimo Tornatore
    2023 Full text Journal of Optical Communications and Networking

    This JOCN special issue contains extended versions of selected papers presented at the 26th International Conference on Optical Network Design and Modeling (ONDM 2022), which took place 16–19 May 2022 at Warsaw University of Technology, Warsaw, Poland. The topics covered by the papers represent trends in optical networking research: application of machine learning to network management, cross-layer network performance optimization, visible light communication as well as coherent metro networks.

  • Invariant Measures for Uncountable Random Interval Homeomorphisms
    • Tomasz Szarek
    • Janusz Morawiec
    2023 Full text Qualitative Theory of Dynamical Systems

    A necessary and sufficient condition for the iterated function system { f (·, ω) | ω ∈ } with probability P to have exactly one invariant measure μ∗ with μ∗((0, 1)) = 1 is given. The main novelty lies in the fact that we only require the transformations f (·, ω) to be increasing homeomorphims, without any smoothness condition, nei- ther we impose conditions on the cardinality of . In particular, positive Lyapunov exponents conditions are replaced with the existence of solutions to some functional inequalities. The stability and strong law of large numbers of the considered system are also proven.

  • Investigating the disease- modifying properties of sclerotiorin in Alzheimer's therapy using acetylcholinesterase inhibition
    • Aravind Ayyolath
    • Anoop Kallingal
    • Varun Thachan Kundil
    • Akshay Maniyeri Suresh
    • Jayadevi Variyar E.
    2023 Chemical Biology & Drug Design

    Alzheimer's disease (AD) is a progressive neurodegenerative disorder caused due to the damage and loss of neurons in specific brain regions. It is the most common form of dementia observed in older people. The symptoms start with memory loss and gradually cause the inability to speak and do day-to-day activities. The cost of caring for those affected individuals is huge and is probably beyond most developing countries capability. Current pharmacotherapy for AD includes compounds that aim to increase neurotransmitters at nerve endings. This can be achieved by cholinergic neurotransmission through inhibition of the cholinesterase enzyme. The current research aims to find natural substances that can be used as drugs to treat AD. The present work identifies and explains compounds with considerable Acetylcholinesterase (AChE) inhibitory activities. The pigment was extracted from the Penicillium mallochii ARA1 (MT373688.1) strain using ethyl acetate, and the active compound was identified using chromatographic techniques followed by structural confirmation with NMR. AChE inhibition experiments, enzyme kinetics, and molecular dynamics simulation studies were done to explain the pharmacological and pharmacodynamic properties. We identified that the compound sclerotiorin in the pigment has AChE inhibitory activity. The compound is stable and can bind to the enzyme non-competitively. Sclerotiorin obeys all the drug-likeliness parameters and can be developed as a promising drug in treating AD.

  • Investigating the Effects of Geometrical Parameters of Re-Entrant Cells of Aluminum 7075-T651 Auxetic Structures on Fatigue Life
    • Amir Ghiasvand
    • Alireza Fayazi Khanigi
    • John W. Grimaldo Guerrero
    • Hamed Aghajani Derazkola
    • Jacek Tomków
    • Anna Janeczek
    • Adrian Wolski
    2023 Full text Coatings

    In this study, the effects of two geometrical parameters of the re-entrant auxetic cells, namely, internal cell angle (θ) and H/L ratio in which H is the cell height, and L is the cell length, have been studied on the variations of Poisson’s ratio and fatigue life of Aluminum 7075-T6 auxetic structures. Five different values of both the H/L ratio and angle θ were selected. Numerical simulations and fatigue life predictions have been conducted through the use of ABAQUS (version 2022) and MSC Fatigue (version 11.0) software. Results revealed that increases in both the H/L ratio and angle θ improved the average value of Poisson’s ratio. Increasing the H/L ratio from 1 to 1.4 and θ from 50° to 70° increased the values of Poisson’s ratio, respectively, 7.7% and 80%. In all angles, increasing the H/L values decreased the fatigue life of the structures significantly. Furthermore, in all H/L values, an increment in θ caused a reduction in fatigue life. The effects of H/L and θ parameters on fatigue life were dominant in the low cycle fatigue regime. Results also showed that the H/L ratio parameter had greater influence as compared to the θ angle, and the structures with higher auxeticity experienced higher fatigue resistance. It was found that the auxetic property of the structure has a direct relationship with the fatigue resistance of the structure. In all samples, structures with greater auxetic property had higher fatigue resistance.

  • Investigation of the Efficiency of a Dual-Fuel Gas Turbine Combustion Chamber with a Plasma‒Chemical Element
    • Serhiy Serbin
    • Badri Diasamidze
    • Marek Dzida
    • Daifen Chen
    2023 Full text Polish Maritime Research

    The study is devoted to the possibility of increasing the efficiency of the working process in dual-fuel combustion chambers of gas turbine engines for FPSO vessels. For the first time, it is proposed to use the advantages of plasma‒chemical intensification of the combustion of hydrocarbon fuels in the dual-fuel combustion chambers, which can simultaneously operate on gaseous and liquid fuels. A design scheme of a combustion chamber with a plasma‒chemical element is proposed. A continuous type mathematical model of a combustion chamber with a plasma‒chemical element has been developed, which is based on the solution of a system of differential equations describing the processes of chemical reactions in a turbulent system, taking into consideration the initiating effect of the products of plasma‒chemical reactions on the processes of flame propagation. A modified six-stage kinetic scheme of hydrocarbon oxidation was used to simultaneously predict the combustion characteristics of the gaseous and liquid fuels, taking into account the decrease in the activation energy of carbon monoxide oxidation reactions when the products of the plasma‒chemical element are added. The results reveal that the addition of plasma‒chemical products significantly reduces CO emissions in the outlet section of the flame tube (from 25‒28 ppm to 3.9‒4.6 ppm), while the emission of nitrogen oxides remains practically unchanged for the studied combustion chamber. Further research directions are proposed to enhance the working process efficiency of a dual-fuel combustion chamber for gas turbine engines as part of the power plant of FSPO vessels.

  • Investigation of the Few‐Layer Black Phosphorus Degradation by the Photonic Measurements
    • Małgorzata Szczerska
    • Monika Kosowska
    • Jakub Gierowski
    • Mateusz Cieślik
    • Mirosław Sawczak
    • Paweł Jakóbczyk
    2023 Full text Advanced Materials Interfaces

    Few-layer black phosphorus (FLBP) is a 2D material that gains worldwide interest for its possible applications, mainly in electronics and optoelec-tronics. However, as FLBP is prone to a degradation process under envi-ronmental conditions, there is a need for a monitoring method allowing investigation of its surface quality. Among many techniques, optoelectronic ones have unique advantages of fast response, non-contact, and non-invasive operation. In this paper, a photonic method is presented for this purpose with a focus on the earliest stages of the degradation process. Measurements are performed using a fiber-optic interferometer working at the wavelength of 1310 nm. Series of material characterization measurements, including scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy investigations are performed to examine the FLBP using a well-established methodology. Two samples—with liquid exfoliated FLBP and with layers of supernatant—prepared in two different production processes are investigated over 3 h. A detailed presentation of the degradation process is provided. The results prove that the surface monitoring of FLBP is possible by registering optical signal changes correlated with the changes in optical parameters caused by the proceeding degradation process.

  • INVESTIGATION OF THE LOMBARD EFFECT BASED ON A MACHINE LEARNING APPROACH
    • Grazina Korvel
    • Povilas Treigys
    • Krzysztof Kąkol
    • Bożena Kostek
    2023 Full text International Journal of Applied Mathematics and Computer Science

    The Lombard effect is an involuntary increase in the speaker’s pitch, intensity, and duration in the presence of noise. It makes it possible to communicate in noisy environments more effectively. This study aims to investigate an efficient method for detecting the Lombard effect in uttered speech. The influence of interfering noise, room type, and the gender of the person on the detection process is examined. First, acoustic parameters related to speech changes produced by the Lombard effect are extracted. Mid-term statistics are built upon the parameters and used for the self-similarity matrix construction. They constitute input data for a convolutional neural network (CNN). The self-similarity-based approach is then compared with two other methods, i.e., spectrograms used as input to the CNN and speech acoustic parameters combined with the k-nearest neighbors algorithm. The experimental investigations show the superiority of the self-similarity approach applied to Lombard effect detection over the other two methods utilized. Moreover, small standard deviation values for the self-similarity approach prove the resulting high accuracies.

  • Investigation of the structural and thermal properties of aluminum-rich Ca–Al–Si–O–N glasses
    • Sharafat Ali
    • Jacek Ryl
    • Abbas Saeed Hakeem
    • Katarzyna Grochowska
    • Natalia Wójcik
    2023 PROGRESS IN SOLID STATE CHEMISTRY

    In this paper, we investigate the structure and thermal properties of aluminum-rich transparent Ca–Al–Si–O–N glasses. The obtained glasses were prepared by a traditional melt-quenching technique at 1650 °C using AlN as the nitrogen source. The obtained glasses have a nAl/nSi>1 and contain up to 17 eq.% of N. The structure of the glasses was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, infrared, and Raman spectroscopy techniques. The structure analysis shows a higher preference for Si–N bond formation relative to Al–N bond formation and aluminum is predominately present in tetrahedral coordination as AlO4 units. The thermal properties of samples were studied by differential thermal analysis and the obtained glass transition temperature ranges from 875 °C to 950 °C, and is primarily influenced by the N content. The glass stability can be correlated with both the N and Al contents in the studied glasses. It is improved due to the increased degree of network polymerization by the incorporation of nitrogen.

  • Investigation on Filaments for 3D Printing of Nasal Septum Cartilage Implant
    • Przemysław Gnatowski
    • Karolina Gwizdała
    • Agnieszka Kurdyn
    • Andrzej Skorek
    • Ewa Augustin
    • Justyna Kucińska-Lipka
    2023 Full text Materials

    Septoplasty is a widely used method in treating deviated septum. Although it is successfully implemented, there are problems with excessive bleeding, septal perforation, or infections. The use of anatomically shaped implants could help overcome these problems. This paper focuses on assessing the possibility of the usage of a nasal septum cartilage implant 3D printed from various market-available filaments. Five different types of laments were used, two of which claim to be suitable for medical use. A combination of modeling, mechanical (bending, compression), structural (FTIR), thermal (DSC, MFR), surface (contact angle), microscopic (optical), degradation (2 M HCl, 5 M NaOH, and 0.01 M PBS), printability, and cell viability (MTT) analyses allowed us to assess the suitability of materials for manufacturing implants. Bioflex had the most applicable properties among the tested materials, but despite the overall good performance, cell viability studies showed toxicity of the material in MTT test. The results of the study show that selected filaments were not suitable for nasal cartilage implants. The poor cell viability of Bioflex could be improved by surface modification. Further research on biocompatible elastic materials for 3D printing is needed either by the synthesis of new materials or by modifying existing ones.

  • Investigation on polypropylene friction stir joint: effects of tool tilt angle on heat flux, material flow and defect formation
    • Fan Guangle
    • Jacek Tomków
    • Mahmoud E. Abdullah
    • Hamed Aghajani Derazkola
    2023 Full text Journal of Materials Research and Technology-JMR&T

    Tool tilt angle (TTA) is a critical factor that can control material flow in polymeric materials' friction stir joining (FSJ). This study selected a TTA range between 0° to 4° for FSJ of polypropylene (PP) polymer sheet. A modified computational fluid dynamic (CFD) technique was implemented to gain a deep understanding of the effects of TTA during FSJ of PP. The PP joint's internal flow, defect formation, heat generation, and tensile strength were investigated experimentally. The fracture surface of tensile samples was analyzed by scanning electron microscopy (SEM). Heat generation, heat flux, and defect formation results from simulation were evaluated by experimental tests output. The results indicate that the PP flow during FSJ is susceptible to TTA. Non-uniform volumetric weight transfer was caused at higher TTA in the joint line, which leads to tilted heat flux. At higher TTA, the generated heat increases, leading to PP exit from the joint line and internal gaps. According to selected parameters, the most robust joint (66 MPa) was produced at 1° TTA. The main reason for the mechanical properties of the PP joint was a dimension of the stir zone and internal defects. Shrinkage gaps were the root of crack initiation during the tensile test, and some local stretching in the fracture surface of the tensile sample after the test was detected.

  • Investing in wine, precious metals and G-7 stock markets – A co-occurrence analysis for price bubbles
    • Marcin Potrykus
    2023 International Review of Financial Analysis

    This paper used the GSADF test to determine the periods defined in this paper as price bubbles in the three markets studied, i.e. the investment wine market, precious metal market and national stock market indices of G-7 countries. The results obtained enabled the calculation of the values of the phi correlation coefficients, which served the research objective of assessing the co-occurrence of price bubbles in the markets analysed. The research period adopted in the study was December 2003 to March 2022, and the data were examined at a monthly frequency. Based on the results, it was concluded that the periods of price bubbles in the investment wine market, relative to the other investments studied, are long and amount to a maximum of 50% of the time studied. Price bubble periods for investments in the DAX index and the Rhone 100 index or the Rest of the World 60 index will lower the risk of an investment portfolio in times of greatest turbulence in these markets. In addition, the co-occurrence of price bubbles was not confirmed for the S&P500 index and the Bordeaux Legends 40 investment. Moreover, no co-occurrence of price bubbles was identified between investments in most of the wine indices studied and investments in silver and gold. However, the same phenomenon was not confirmed for platinum investments.

  • Ionic thermoelectric effect in Cu2-δSe during phase transition
    • Bartosz Trawiński
    2023 Full text JOURNAL OF MATERIALS SCIENCE

    The ionic Seebeck coefficient was studied in copper selenide with Cu1.99Se, Cu1.95Se and Cu1.8Se stoichiometry which was synthesized with a melt crystallization method. To measure the ionic Seebeck coefficient of copper ions, 0.15C6H12N4CH3I + 0.85CuI solid-state electrolyte was prepared. Electrolyte layers were pressed with copper selenide powder into a sandwich-like structure. At the temperature of 410 K, the materials have ionic Seebeck coefficient values close to each other, about 1100 μV/K. In the case of β-phase structure (Cu1.8Se material), changes in the measured Seebeck coefficient were observed—with decreasing temperature, the ionic thermopower firstly increased reaching about 1230 μV/K and then decreased to 950 μV/K at 355 K. In the Cu1.99Se material, a phase transition to the α-phase was observed during cooling. The ionic Seebeck coefficient values gradually increased from 1030 to 1220 μV/K at 370 K, when the material is in the low-temperature phase. The measured difference between the ionic thermopower of the two phases well matches calculations based on the entropy of the transition (presence part of the Seebeck coefficient) and different activation energies of ionic transport (transport part).

  • Ionosphere variability I: Advances in observational, monitoring and detection capabilities
    • Ioanna Tsagouri
    • Anna Belehaki
    • David R. Themens
    • Norbert Jakowski
    • Tim Fuller-Rowell
    • Mainul M. Hoque
    • Grzegorz Nykiel
    • Wojciech J. Miloch
    • Claudia Borries
    • Anna Morozova
    • Teresa Barata
    • William Engelke
    • Ja-Soon Shim
    2023 ADVANCES IN SPACE RESEARCH

    The paper aims to review recent advances regarding the observational and monitoring capabilities of the ionization conditions in the Earth's upper atmosphere. The analysis spans both ground and space-based experiments, seeking for new installations and/or missions, new or upgraded instrumentation and/or observational network establishments as means for advancing current understanding and prediction ability of the ionosphere variability. As a solid basis and a clear requirement for considerable advances in the field, progress towards the more efficient access to research facilities and data centres is also investigated. Giving the emphasis in the period from 2015 onwards, the ultimate goal of the present analysis is to assess present status with respect to the COSPAR/ILWS Space Weather roadmap's considerations/recommendations for 2015–2025 as input to the roadmap’s update undertaken by the ISWAT/COSPAR action.

  • Ionosphere variability II: Advances in theory and modeling
    • Ioanna Tsagouri
    • David R. Themens
    • Anna Belehaki
    • Ja-Soon Shim
    • Mainul M. Hoque
    • Grzegorz Nykiel
    • Claudia Borries
    • Anna Morozova
    • Teresa Barata
    • Wojciech J. Miloch
    2023 ADVANCES IN SPACE RESEARCH

    This paper aims to provide an overview on recent advances in ionospheric modeling capabilities, with the emphasis in the efforts relevant to electron density variability. The discussion spans a wide range of model formulations (e.g., from purely empirical to physics-based ones and data-driven approaches) seeking for advances or gaps with regard to present challenges. This discussion is further supported by consideration of the models' assessment and accessibility, as well as scientific advances that may drive further improvements in our modeling capabilities. Giving the emphasis in the period from 2015 onwards, the ultimate goal of the present analysis is to comment on progress with respect to the COSPAR/ILWS Space Weather roadmap's considerations/recommendations for 2015–2025 as input to the roadmap’s update undertaken by the ISWAT/COSPAR action.

  • IRREGULARITIES IN UNIVERSITY PROCESSES CONCERNING THE LEAN MANAGEMENT TYPOLOGY. THE PILOT STUDY RESULTS
    • Piotr Grudowski
    • Małgorzata Wiśniewska
    2023 Full text Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

    Purpose: Identify the attitudes regarding key irregularities in university activities of universities referring to muda, mura, and muri from the perspective of two groups of stakeholders - academic teachers and administration/service personnel. Study design/methodology/approach: A pilot quantitative study using a questionnaire containing 48 statements regarding six categories of irregularities assessed according to the 5-point Likert scale. We asked two research questions: Q1. Is the questionnaire used in the study reliable for assessing attitudes regarding irregularities that occur in connection with work at the university? Q2. Which categories of irregularities most often accompany work at the university, and how is their nuisance assessed? Findings: The reliability of the research tool was statistically confirmed. Respondents represent an attitude close to indifference regarding the perception of most categories of irregularities. The most often indicated by both groups of respondents is "Unused creativity of employees.” Respondents consider all types a "nuisance" to a greater than moderate degree. Originality/value: We propose an original tool to assess irregularities in higher education institutions and apply it in the Polish and possibly international environment. These studies constitute an initial stage of the planned in-depth original research aimed at using the classification of irregularities/losses in surveys of the opinions of all higher education stakeholders (e.g., students, employers), indicating the critical causes of problems and directions of improvement activities.

  • Is it possible to create a unified urban greenery management system (UGMS) on a national scale? The concept for EU Member State of Poland
    • Agnieszka Dawidowicz
    • Marcin Kulawiak
    • Marek Ogryzek
    2023 ENVIRONMENTAL SCIENCE & POLICY

    Motives: Currently developed urban greenery management systems (UGMS) are limited in scope and profiled towards solving particular issues. Moreover, due to the lack of common standards and solutions, UGMS implementation requires considerable financial effort, which is only feasible for wealthy urban centres. There is a need for universal, cost-effective technological solutions which could constitute a common urban green infrastructure at all country administrative levels. Aim: This research aims to present a technological architecture of a universal UGMS capable of data integration and analysis at both local and central administrative levels, and present its prospective data management functionality through a proof-of-concept implementation by the example of Olsztyn city, located in the EU Member State of Poland. Methods: Empirical study has been conducted by means of qualitative assessment through state-of-the-art analysis of green information systems, national spatial data infrastructure (NSDI) including land administration system (called Integrated Real Estate Information System) and Geoportal, development and testing of a proof-of-concept solution through management, analysis and visualizations of green areas, objects and related phenomena; quantitative assessment has been performed through in-situ inventory of urban greenery in the City of Olsztyn, Poland. Results: The presented study resulted in a concept UGMS architecture based on existing NSDI. The projected functionality of the designed UGMS has been implemented and tested on a real-world urban greenery database. The research thesis, that open databases integrated with national SDI data are sufficient to create a uniform and complete nationwide UGMS was confirmed.

  • Is mesh fixation necessary in laparoendoscopic techniques for M3 inguinal defects? An experimental study.
    • Mateusz Zamkowski
    • Agnieszka Tomaszewska
    • Izabela Lubowiecka
    • Krzysztof Karbowski
    • Maciej Śmietanski
    2023 SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES

    repairs, in case of large direct hernias (M3) mesh fixation is recommended to reduce recurrence risk. Despite lack of highquality evidence, the recommendation was upgraded to strong by expert panel. The authors conducted a research experiment to verify the hypothesis that it is possible to preserve the mesh in the operating field in large direct hernias (M3) without the need to use fixing materials. Method The authors conducted an experiment with scientists from Universities of Technology in a model that reflects the conditions in the groin area. By simulating conditions of the highest possible intra-abdominal pressure, they examined the mesh behavior within the groin and its ability to dislocate under the forces generated by this pressure. The experiment involved six spatial implants and one flat macroporous mesh. Results Heavyweight spatial meshes and lightweight spatial-individualized meshes showed no tendency to dislocate or move directly to the orifice, which was considered a rapid hernia recurrence. Lightweight meshes, both spatial and flat, underwent significant migration and shifting toward the hernial orifices. Conclusion Based on the results, we believe that mesh fixation is not the only alternative to preventing recurrence in complex defects. Similar effects can be achieved using a larger, more rigid, and anatomically fitted implant. The type of implant (rather than its fixation) seems to be a key factor from the point of view of mechanics and biophysics. Clinical trials confirming the results in vivo will allow to supplement or amend the guidelines for the treatment of large inguinal hernias.

  • Isolation of Citrus lemon extracellular vesicles: Development and process control using capillary electrophoresis
    • Aleksandra Steć
    • Martyna Chodkowska
    • Joanna Kasprzyk-Pochopień
    • Przemyslaw Mielczarek
    • Wojciech Piekoszewski
    • Bogdan Lewczuk
    • Agata Płoska
    • Leszek Kalinowski
    • Bartosz Wielgomas
    • Szymon Dziomba
    2023 FOOD CHEMISTRY

    A new and scalable method for the isolation of extracellular vesicles (EV) from Citrus lemon juice samples was developed. The methodology included preliminary preconcentration of the sample using ultrafiltration (UF) followed by size-exclusion chromatography (SEC) purification and final preconcentration of the eluates. Transmission electron microscopy and proteomic analysis showed that isolates contained exosome-like vesicles, exocyst-positive organelle (EXPO), and microvesicles. The efficiency of certain isolation steps was evaluated with total protein content assay (bicinchoninic acid assay, BCA), nanoparticles tracking analysis (NTA), and capillary electrophoresis (CE). A good correlation between CE, BCA, and NTA results was shown. The application of CE enabled the detection of soluble contaminants, macromolecular aggregates, and vesicles’ heterogeneity. The fluorescent staining of encapsulated nucleic acids was proposed for the identity confirmation of EV detected in CE. The study demonstrates the CE as a comprehensive tool for monitoring of the EV isolation process.

  • "istota zamieszkiwania: refleksje wpasowane [bio]morficznie. DWA PARKI | DWA ŚWIATY"
    • Agnieszka Kurkowska
    2023

    Myśląc o zamieszkiwaniu poruszam się w nurcie filozofii przyrody. Park Schopenhauera jest punktem odniesienia dla uwolnienia refleksji dotykającej ludzkich schronień. Domy, ich postaci kompletne są celem procesu, którego etapem jest tworzenie rzeźb zaprezentowanych w otwartej przestrzeni przyrodniczo-kulturowej. W Oliwie, pośród drzew, wzdłuż Potoku Oliwskiego umieszczony został cykl rzeźb zatytułowanych „istota zamieszkiwania: relacje [nie]codzienne”. Park Oruński koresponduje z Parkiem Oliwskim poprzez elementy skorelowanych wystaw. Obie prezentacje pozostają w ścisłej relacji i nawiązują do siebie. Temat przewodni jest wspólny: SCHRONIENIE. To punkt wyjścia pracy nad projektem. Prezentacje ukazują dwie rzeczywistości: wyobrażoną i fizyczną. Przestrzeń idei i przestrzeń kreacji. W praktyce projektanta są nierozłączne. Artysta może spróbować wyabstrahować fragmenty zjawiska dla skupienia uwagi na konkretnym aspekcie. OLIWA to obiekty dla miejsca, ORUNIA to obiekty w procesie, prezentujące idee i odwołania. Dwa miejsca to korespondencja w czasie i przestrzeni ukazująca współistniejące, ale dopuszczające autonomię refleksji, rzeczywistości namacalną fizyczność i abstrakcyjną, efemeryczną ideę.

  • istota zamieszkiwania: relacje [nie]codzienne Biomorfizm w poszukiwaniach formuły domu. Między formą a bezformiem schronienia. wystawa indywidualna cykl rzeźbiarski: 10 zestawów obiektów | glina suszona
    • Agnieszka Kurkowska
    2023

    Dom formę posiadać może, nie musi. Czasem dom jest tworem abstrakcyjnym. Lokuje się w wyobraźni, we wspomnieniach, regułach, opisie, obrazie. Paradoksalnie zatem, dom formy nie potrzebuje dla istnienia. Zazwyczaj jednak to o jego fizyczność chodzi. Potrzebny jest dom namacalny. Dom chroniący. Tak podpowiada ludzka fizyczność. Nasza egzystencja wymaga obudowy, schronienia, miejsca przechowywania, stref wydzielonych dla wykonywania określonych czynności życiowych. Dom: uosobowienie miejsca. Tworzenie domu to poszukiwanie pierwotnego sensu i istoty zamieszkiwania zawartych w idei schronienia, istniejącej poza czasem, w swojej ideowej formie także poza miejscem. Autorski projekt oparto na koncepcji scalenia form odkulturowych z elementami przyrodniczymi w nurcie biomorficznym. Biomorfizm nie oznacza antropologicznej opozycji ludzkie i nie-ludzkie. To szansa działania w nurcie posthumanistycznych poszukiwań podobieństw wśród wszystkich żywych gatunków współistniejących dzięki koegzystencji. Człowiek powinien zrewidować sytuowanie siebie w roli nadrzędnej. Rzeczywistość antropocentryczna nie zapewni gatunkom żywym schronienia na zdegradowanej planecie. Amorficzna masa gliny i refleksja twórcza stanowią o zaistnieniu ideowych rzeźb architektonicznych. Amorfizm jest źródłem biomorficznej formy schronienia. Rozpoczyna cykl życiowy obiektu. Kształtowanie w funkcji czasu, doprecyzowywanie bryły, spasowywanie z miejscem, wpasowywanie w wizję twórczą obarczone [nie] codziennymi relacjami ze światem przyrodniczym i kulturowym. Powstaje obiekt, który zostaje naznaczony cechami kulturowymi. Wykonanie wgłębień przywołujących kształtem skojarzenie z otworami budynku zmienia skalę i charakter doświadczenia. Przenosi rzeźbę z obszaru sztuki czystej w sferę użytkową. Odnajduje odwołania i skojarzenia. Czyni oswajalnym. Prowokuje do rozważań o formie domu powoływanego autorską metodą pozwala skonfrontować zastany obiekt w konkretnym kontekście z osobistą wizją domu własnego, wyobrażonego, poszukiwanego. Rzeźby kształtowane biomorficznie czerpią kształt z zastanych elementów przyrodniczych. Powstaje spasowany dotykiem, wymodelowany w rodzimym materiale obiekt. Ukazujący formułę domu, który powstaje, istnieje, degraduje się i znika. Przechodzi w niebyt jako forma, ale jego substancja wraca do systemu, który go zrodził. Przenosi jego fizyczne cząstki w inne struktury i byty, a zawarte idee w przestrzeń rozważań. Ten proces jest mu przypisany jako zasada egzystencji.

  • Jeffreys heat conduction in coupled semispaces subjected to interfacial heating
    • Oleksii Nosko
    2023 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER

    A Jeffreys heat conduction problem for coupled semispaces subjected to the action of an interfacial heat source was defined. An analytical solution of the problem was derived for a polynomial specific power of the heat source using the Laplace transform approach. The asymptotic and parametric analysis was performed for different ratios of thermal conductivities , thermal diffusivities , thermal relaxation times and coefficients indicating the relative contribution of Fourier heat conduction. It was found that Jeffreys heat conduction results in continuous variation of the contact temperature, whilst its particular case — Cattaneo heat conduction — is accompanied by a step change of the contact temperature at the initial time. Another finding is that the initial heat partition occurs due to the ratio of and under Jeffreys heat conduction and due to the different ratio of and under Cattaneo heat conduction. The solution applicability was demonstrated on the simulation example of ultrashort laser pulse welding. The type of heat conduction was revealed to have qualitative and quantitative impacts on the contact temperature and heat fluxes.

  • Joint foreign ownership and global value chains effects on productivity: a comparison of firms from Poland and Germany
    • Sabina Szymczak
    • Aleksandra Parteka
    • Joanna Wolszczak-Derlacz
    2023 Full text International Journal of Emerging Markets

    Purpose The study aims to examine the joint effects of foreign ownership (FO) and involvement in global value chains (GVCs) on the productivity performance of firms from a catching-up country (Poland) and a leader economy (Germany). Design/methodology/approach The authors use micro-level data on firms combined with several sector-level GVC participation measures. The authors investigate whether the link between productivity and the overall sectoral degree of involvement in global production structures depends on a firm's ownership. The authors verify the robustness of the obtained results by using an instrumental variables approach and weighted regression. Findings The results show that domestically owned firms are less productive than foreign ones, which is particularly true at low GVC participation levels. However, as GVC involvement increases, the FO productivity premium decreases, leading to productivity catching up between foreign and domestically owned firms. This mechanism is similar in Poland and Germany. However, in the leader country (Germany), the productivity performance of domestically owned firms is more stable along the distribution of GVC involvement. Originality/value This study contributes to the foreign direct investment (FDI)–productivity literature by comparing the catching-up and developed countries' perspectives and incorporating the productivity–GVC relationship into the FDI analysis. The authors show that the FO premium is not confined to the developing context but is also present in a leader country. Moreover, the link between productivity and the overall sectoral degree of involvement in global production structures depends on a firm's ownership.

  • Kagome Lattice Promotes Chiral Spin Fluctuations
    • Kamil Kolincio
    • Max Hirschberger
    • Jan Masell
    • Taka-hisa Arima
    • Naoto Nagaosa
    • Yoshinori Tokura
    2023 Full text PHYSICAL REVIEW LETTERS

    Dynamical spin fluctuations in magnets can be endowed with a slight bent toward left- or right-handed chirality by Dzyaloshinskii-Moriya interactions. However, little is known about the crucial role of lattice geometry on these chiral spin fluctuations and on fluctuation-related transport anomalies driven by the quantum-mechanical (Berry) phase of conduction electrons. Via thermoelectric Nernst effect and electric Hall effect experiments, we detect chiral spin fluctuations in the paramagnetic regime of a kagome lattice magnet; these signals are largely absent in a comparable triangular lattice magnet. Supported by Monte Carlo calculations, we identify lattices with at least two dissimilar plaquettes as most promising for Berry phase phenomena driven by thermal fluctuations in paramagnets.

  • Kapitał marki miasta Gdańska - ujęcie marketingowe
    • Anna Dziadkiewicz
    • Ewelina Sokołowska
    • Piotr Juchniewicz
    2023

    Kapitał marki miasta obejmuje zestaw jego unikalnych cech, które umożliwiają rywalizowanie o potencjalnych klientów: mieszkańców, turystów, studentów czy też inwestorów. Niniejszy rozdział dotyczy problematyki czynników kształtujących markę miasta Gdańsk określonych na podstawie wyników badania jakościowego. Zostało ono przeprowadzone w formie wywiadu z ekspertami zajmującymi się zawodowo kreowaniem marki miast. Wyboru respondentów dokonano zgodnie z założeniami teorii ugruntowanej, która opiera się na przesłance, że rzeczywistość społeczną najlepiej rozumieją podmioty w nią zaangażowane. Uzyskane odpowiedzi umożliwiły stworzenie mapy prezentującej zależności dotyczące kapitału marki miasta Gdańsk. Rezultaty badania mogą być wykorzystane przez organy zajmujące się budowaniem wizerunku miasta, wpływając na ulepszanie jego oferty, doskonalenie komunikacji z interesariuszami a także na ocenę działań marketingowych mających na celu rozwój marki miasta Gdańsk.

  • Karhunen-Loeve-based approach to tracking of rapidly fading wireless communication channels
    • Maciej Niedźwiecki
    • Artur Gańcza
    2023 SIGNAL PROCESSING

    When parameters of wireless communication channels vary at a fast rate, simple estimation algorithms, such as weighted least squares (WLS) or least mean squares (LMS) algorithms, cannot estimate them with the accuracy needed to secure the reliable operation of the underlying communication systems. In cases like this, the local basis function (LBF) estimation technique can be used instead, significantly increasing the achievable tracking accuracy. We show that when some prior knowledge of statistical properties of parameter changes is available, such as the bandwidth of their variation, both the type and the number of basis functions, used in the LBF approach to approximate time-varying channel parameters, can be optimized using the Karhunen-Loève (KL) decomposition based technique.

  • KASZUBSKIE KWIATY. ogrody i tradycja: żywe dziedzictwo. warsztaty w ramach Bałtyckiego Festiwalu Nauki
    • Agnieszka Kurkowska
    2023

    Warsztaty dla dzieci dotyczyły tradycyjnych ogrodów i przedogrodków kaszubskich - ważnego elementu kultury regionalnej i dziedzictwa. Kwiaty odgrywają w nich rolę kluczową, bo poza właściwościami użytkowymi rośliny stanowią inspirację wzorniczą. Dzieci posadziły nasiona malwy - kwiatu o wyjątkowym pięknie i szerokim zastosowaniu w kuchni i medycynie naturalnej. Wypartej przez powszechnie dostępne, popularne gatunki roślin ogrodniczych Celem było zrozumienie i podtrzymanie tradycji lokalnej.

  • Keratin-Butyrate Scaffolds Promote Skin Wound Healing in Diabetic Rats Through Down-Regulation of IL-1β and Up-Regulation of Keratins 16 and 17
    • Marek Konop
    • Mateusz Rybka
    • Mateusz Szudzik
    • Łukasz Mazurek
    • Anna Laskowska
    • Dorota Sulejczyk
    • Zbigniew Ruszczak
    • Rafał Mazgaj
    • Bartłomiej Cieślik
    • Robert Schwartz
    • Emilia Samborowska
    • Jakub Frankowski
    • Adam Waszkowski
    • Piotr Konopelski
    • Joanna Czuwara
    2023 Full text Journal of Natural Fibers

    Impaired wound healing particularly in diabetics creates a significant healthcare burden. The study aimed to evaluate the effect of keratin-butyrate fibers (FKDP +0.1%NaBu) in a full-thickness skin wound model in 30 diabetic rats. Physicochemical examination showed that the obtained dressing possesses a heterogeneous structure and butyrate was slowly released into the wound. Moreover, the obtained dressing is nontoxic and supports cell growth. In vivo results showed that keratin-butyrate dressing accelerated wound healing on days 4 and 7 post-injury (p < .05). Histopathological and immunofluorescence examination revealed that applied dressing stimulated macrophage infiltration, which favors tissue remodeling and regeneration. The dressing was naturally incorporated into regenerating tissue. The highest mRNA expression level of interleukin 1β (IL-1β) was observed during the first 2 weeks in the control wounds compared to FKDP +0.1%NaBu treated wounds, in which IL-1β was significantly decreased. In FKDP +0.1%NaBu dressed wounds, mRNA expression of IL-10 and VEGF increased significantly (p < .05) from day 14. Keratin-butyrate treated wounds enhanced mRNA expression of keratin 16 and 17 and zonula occludens protein-1 and junctional adhesion molecules (p < .05) on days 14, 21, and 28 post-injuries. Our study showed that keratin butyrate dressing is safe and can efficiently accelerate skin wound healing in diabetic rats.

  • Key activities to improve energy management in DC microgrids connected by urban traction
    • Kawsar Nassereddine
    • Marek Turzyński
    • Mykola Lukianov
    • Natalia Strzelecka
    2023 Full text Przegląd Elektrotechniczny

    DC MicroGrids must have Energy Management Systems to guarantee efficient, dependable, and environmentally friendly electricity. The application of Model Predictive Control, proved to be helpful due to its adaptability and capacity to use non-linear models. This paper, based on an extensive literature review, identifies and discusses the three key activities to improve the characteristics of DC MicroGrids, i.e.: the use of Energy Storage Systems), the implementation of Demand Side Management, and the use of Model Predictive Control.

  • Kinetics of Intermetallic Phase Precipitation in Manual Metal Arc Welded Duplex Stainless Steels
    • Monika Orłowska
    • Krzysztof Pańcikiewicz
    • Aleksandra Świerczyńska
    • Michał Landowski
    2023 Full text Materials

    The article presents the influence of heat treatment on the kinetics of transformations in lean duplex LDX2101 steel and a weld made of standard duplex 2209 material, which was welded by manual metal arc welding. Changes in the microstructure, hardness, and magnetic phase content were analyzed after heat treatment was conducted at a temperature of 800 °C for a period ranging from 15 to 1440 min. Light and scanning microscopy, Vickers hardness measurements, and magnetic phase content measurements using a ferritoscope were used for the research. In the LDX2101 steel, the presence of δ-ferrite and γ austenite was identified and additional Cr2N nitrides were observed in the heat-affected zone. After heat treatment, the decomposition of δ ferrite into γ2 austenite and Cr2N nitrides was observed in both areas. In the case of weld made by the coated electrode in 2209 grade, a ferritic–austenitic microstructure with allotriomorphic austenite (γA), Widmanstätten austenite (γW), and idiomorphic austenite (γI) and δ-ferrite area with “bee swarms” of fine precipitations of chromium nitrides Cr2N and non-metallic inclusions (NMIs) of slag, formed during the welding process, are observed in the as-welded state. After heat treatment, the presence of the χ phase (after 15 min of annealing) and the σ phase (after 120 min of annealing) was additionally identified. The kinetics of intermetallic phase evolution in welds made from 2209 material were presented. The obtained results of hardness measurements and metallographic tests were correlated, which allowed for a quick check of the precipitation processes on the used element.

  • Klasyczne wzorce urbanistyczne w „miastach tymczasowych” na przykładzie skautowych zlotów Jamboree
    • Oskar Amiri
    2023 Full text

    Przedmiotem dysertacji są klasyczne wzorce urbanistyczne w „miastach tymczasowych”, analizowane na przykładzie skautowych zlotów Jamboree, czyli międzynarodowych wydarzeń edukacyjnych dla skautów i skautek, gromadzących kilkanaście lub kilkadziesiąt tysięcy ludzi przez okres około dwóch tygodni. W rozprawie przyjęto perspektywę miasta „tymczasowego”, a zatem formy miejskiej funkcjonującej w pewnych ramach czasowych. Założono, że skautowe zloty Jamboree wpisują się w definicję „miasta tymczasowego” zarówno w zakresie funkcji czasu, jak i celu. W rozprawie przedstawiono rozumienie pojęcia klasycznych wzorców urbanistycznych, wyróżniając trzy kategorie: formy przestrzenne, przestrzenie funkcjonalne i ład przestrzenny. Podstawą analizy ich obecności były materiały kartograficzne projektów zagospodarowania terenu skautowych zlotów Jamboree oraz wnioski z badań społecznych. Pomimo różnic dotyczących rozpoznania poszczególnych klasycznych wzorców urbanistycznych, w każdym z analizowanych przykładów były one identyfikowane i na ogół oceniane pozytywnie. Z analiz i badań wynika, że wzorce urbanistyczne, takie jak np. rynek, ulica, porządek geometryczny, stanowią istotne elementy nie tylko krajobrazu przestrzenno-kulturowego, lecz dotyczą także mniej lub bardziej trwałych warunków życia w tymczasowych strukturach miejskich. Obecność klasycznych wzorców urbanistycznych w „miastach tymczasowych” oraz w świadomości ich użytkowników dowodzi pewnej uniwersalności tych cech oraz potrzeby ładu i harmonii w organizacji przestrzeni miejskiej.

  • KM Challenges in Small KIBS Companies: Multi-case Analysis in Two Countries
    • Ettore Bolisani
    • Tomas Cherkos Kassaneh
    • Anna Lis
    • Enrico Scarso
    • Ewa Stolarek-Muszyńska
    • Małgorzata Zięba
    2023 Full text

    Knowledge Intensive Business Services (KIBS) – i.e. companies like e.g. computer services, consulting, engineering, business communication, and R&D support - are key players in the modern economies. They stimulate the innovativeness of businesses and societies. Their competitiveness is based on knowledge, which is their key production factor and also the kind of “goods” they sell. The large majority of KIBS companies have a small or medium size, which leads to major challenges because they manage their cognitive assets in a substantially informal and undeliberate way. They face several obstacles to managing knowledge, partly due to their limited resources, but also to the knowledge-intensive and intangible nature of their business processes and outputs. Such challenges, when not successfully identified and faced, may negatively impact competitiveness. The paper illustrates the findings of a qualitative investigation aimed at exploring the main KM challenges that KIBS SMEs face. These challenges were analysed with specific reference to the key KM processes, i.e.: knowledge acquisition, knowledge documentation and storage, knowledge sharing, knowledge application, and knowledge protection. The research is a multiple-case study based on interviews to key informants of 23 Italian and Polish KIBS SMEs of different sectors. The analysis made it possible to find recurring issues and highlight differences. The study provides food for thought for researchers and practitioners willing to clarify what KM processes need proper solutions for the effective management of knowledge in small KIBS.

  • Knowledge management implementation in small and micro KIBS : A categorization
    • Ettore Bolisani
    • Enrico Scarso
    • Riccardo Ceccato
    • Małgorzata Zięba
    2023 Full text Knowledge and Process Management

    he main goal of the paper is to provide a statistical categorization of small and micro knowledge-intensive business service (KIBS) companies, based on their knowledge management (KM) attitude. Since knowledge is the main production factor and output of these companies, it is essential to achieve a better understanding of how they manage this resource. A questionnaire-based survey was conducted on a sample of Polish small and micro KIBS operating in various service sectors. A cluster analysis of the data was performed, to categorize the sample according to the KM attitude of the companies. Three main groups of companies were identified, varying in terms of their levels of “knowledge needs”, “intensity of use” of KM practices and “perceived barriers to KM implementation”. This classification is shown to characterize attitudes towards KM to a higher level of statistical significance than do structural characteristics. The survey was based on a single country sample. On the one hand, this provides consistency to the analysis. On the other hand, further insights can be obtained by a multi-national study. In addition, cluster analysis is exploratory in nature. The results provide useful insights for policy makers (to formulate policies for facilitating KM implementation in small KIBS) and managers (to reflect on the KM attitudes of their company). The statistical categorization of small and micro KIBS in terms of their KM attitude has been very rarely undertaken. Even the most recent investigations of KM issues used samples from large companies.

  • Knowledge Risks Arising from Digitalization
    • Małgorzata Zięba
    • Susanne Durst
    • Martyna Gonsiorowska
    2023 Full text

    Purpose - This conceptual paper aims to identify and analyse knowledge risks resulting from digitalization. Additionally, the paper tries to present factors influencing knowledge risks arising from digitalization and ways of handling them. Design/methodology/approach – The study is a continuation of the research by Durst and Zieba (2019) related to knowledge risks and their potential outcomes. This present study makes an update on the literature on knowledge risks arising from digitalization. Originality/value – The paper offers new insights for researchers dealing with the topic of knowledge risks in the context of digitalization and ways of handling them. Practical implications – The study provides insight for each of us, as the issue addressed concerns us all. By becoming aware of the potential consequences of such knowledge risks, people may meet and cope with digitalization in a better, more enlightened way. Limitations – The presented paper is based on prior literature and the authors’ reflections, experience, and analysis. Thus, to check for the suitability of the risks proposed, there is a need for empirical studies. Such studies are planned by the authors in the near future.

  • Knowledge-Based Expedited Parameter Tuning of Microwave Passives by Means of Design Requirement Management and Variable-Resolution EM Simulations
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Ali Raef
    2023 Full text Scientific Reports

    The importance of numerical optimization techniques has been continually growing in the design of microwave components over the recent years. Although reasonable initial designs can be obtained using circuit theory tools, precise parameter tuning is still necessary to account for effects such as electromagnetic (EM) cross coupling or radiation losses. EM-driven design closure is most often realized using gradient-based procedures, which are generally reliable as long as the initial design is sufficiently close to the optimum one. Otherwise, the search process may end up in a local optimum that is of insufficient quality. Furthermore, simulation-based optimization incurs considerable computational expenses, which are often impractically high. This paper proposes a novel parameter tuning procedure, combining a recently reported design specification management scheme, and variable-resolution EM models. The former allows for iteration-based automated modification of the design goals to make them accessible in every step of the search process, thereby improving its immunity to poor starting points. The knowledge-based procedure for the adjustment of the simulation model fidelity is based on the convergence status of the algorithm and discrepancy between the current and the original performance specifications. Due to using lower-resolution EM simulations in early phase of the optimization run, considerable CPU savings can be achieved, which are up to 60 percent over the gradient-based search employing design specifications management and numerical derivatives. Meanwhile, as demonstrated using three microstrip circuits, the computational speedup is obtained without design quality degradation.

  • Kod fontannowy z przyrastającą liczbą symboli źródłowych
    • Kamila Haustein
    • Marek Blok
    2023 Full text Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Kody fontannowe zabezpieczające transmisję przed wymazaniami wyróżnia brak określonej z góry długości i losowy sposób generacji kolejnych pakietów kodowych. W pracy pokazano jak właściwości tych kodów zależą od rozkładu macierzy generującej dla dwóch wariantów dostarczania pakietów do kodera. Szczególnie interesujący jest przypadek, gdy pakiety źródłowe trafiają do kodera stopniowo podczas transmisji. Uzyskane wyniki wskazują na możliwość realizacji transmisji strumieniowej o ograniczonej złożoności i wymaganiach pamięciowych dekodera.