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Gdańsk University of Technology

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  • Pilot-Scale Studies of WO3/S-Doped g-C3N4 Heterojunction toward Photocatalytic NOx Removal
    • Marta Kowalkińska
    • Agnieszka Fiszka Borzyszkowska
    • Anna Grzegórska
    • Jakub Karczewski
    • Paweł Głuchowski
    • Marcin Łapiński
    • Mirosław Sawczak
    • Anna Zielińska-Jurek
    2022 Full text Materials

    Due to the rising concentration of toxic nitrogen oxides (NOx) in the air, effective methods of NOx removal have been extensively studied recently. In the present study, the first developed WO3/S-doped g-C3N4 nanocomposite was synthesized using a facile method to remove NOx in air efficiently. The photocatalytic tests performed in a newly designed continuous-flow photoreactor with an LED array and online monitored NO2 and NO system allowed the investigation of photocatalyst layers at the pilot scale. The WO3/S-doped-g-C3N4 nanocomposite, as well as single components, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller surface area analysis (BET), X-ray fluorescence spectroscopy (XRF), X-ray photoemission spectroscopy method (XPS), UV–vis diffuse reflectance spectroscopy (DR/UV–vis), and photoluminescence spectroscopy with charge carriers’ lifetime measurements. All materials exhibited high efficiency in photocatalytic NO2 conversion, and 100% was reached in less than 5 min of illumination under simulated solar light. The effect of process parameters in the experimental setup together with WO3/S-doped g-C3N4 photocatalysts was studied in detail. Finally, the stability of the composite was tested in five subsequent cycles of photocatalytic degradation. The WO3/S-doped g-C3N4 was stable in time and did not undergo deactivation due to the blocking of active sites on the photocatalyst’s surface.

  • plakat wystawy pt. "Zaspa Nova: osiedle i otoczenie | perspektywa 2030 | studium potencjału miejsca"
    • Agnieszka Kurkowska
    2022

    Plakat jest autorskim projektem plastycznym opartym o fotografię bloku mieszkalnego z Zaspy

  • Planning a Cost-Effective Delay-Constrained Passive Optical Network for 5G Fronthaul
    • Abdulhalim Fayad
    • Manish Jha
    • Tibor Cinkler
    • Jacek Rak
    2022

    With the rapid growth in the telecommunications industry moving towards 5G and beyond (5GB) and the emergence of data-hungry and time-sensitive applications, Mobile Network Operators (MNOs) are faced with a considerable challenge to keep up with these new demands. Cloud radio access network (CRAN) has emerged as a cost-effective architecture that improves 5GB performance. The fronthaul segment of the CRAN necessitates a high-capacity and low-latency connection. Optical technologies presented by Passive Optical Networks (PON) have gained attention as a promising technology to meet the fronthaul challenges. In this paper, we proposed an Integer Linear Program (ILP) that optimizes the total cost of ownership (TCO) for 5G using CRAN architecture under different delay thresholds. We considered the Time and Wavelength Division Multiplexing Passive Optical Network (TWDM-PON) as a fronthaul with different splitting ratios.

  • Planowane krajowe laboratorium badawcze sieci i usług 5G wraz z otoczeniem
    • Burakowski Wojciech
    • Andrzej Bęben
    • Maciej Sosnowski
    • Dariusz Więcek
    • Igor Michalski
    • Józef Woźniak
    • Krzysztof Gierłowski
    • Michał Hoeft
    • Schauer Patryk
    • Arkadiusz Warzyński
    • Marek Natkaniec
    • Piotr Boryło
    • Artur Binczewski
    • Bartosz Belter
    • Maksymilian Furmann
    2022 Full text Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Przedstawiono koncepcję infrastruktury PL-5G pt. Krajowe laboratorium sieci i usług 5G wraz z otoczeniem. Laboratorium to będzie ważną infrastrukturą badawczą w kraju, która powinna w istotny sposób przyczynić do ukierunkowania praktycznych badań dotyczących nowych generacji dla infrastruktur sieciowo-obliczeniowych Internetu. Laboratorium to będzie zlokalizowane w czterech miastach, tj. Gdańsku, Krakowie, Poznaniu i Wrocławiu i będzie miało wspólny system sterowania eksperymentami. Korzystanie z laboratorium będzie zdalne, co umożliwi zespołom krajowym z innych lokalizacji efektywne korzystanie z jego zasobów. Przewiduje się, że będzie również wykorzystywane w procesie dydaktycznym realizowanym przez uczelnie techniczne. Termin zakończenia budowy przewiduje się na koniec 2023r.

  • Płeć jako determinanta w podejmowaniu decyzji menedżerskich w sytuacjach kryzysowych
    • Igor Gielniak
    2022 Full text

    Problem badawczy niniejszej rozprawy określona pytanie: „czy i w jaki sposób płeć wpływa na skuteczność podejmowania decyzji w sytuacjach kryzysowych?”. Analiza literatury z dziedziny zarządzania wykazała małą liczbę badań, dlatego rozszerzoną ją na psychologię, psychologię ewolucyjną, psychologię edukacji, neuropsychologię i socjologię. Przedmiotem pracy są decyzje menedżerskie podejmowane zarówno bezpośrednio przed zaistnieniem, jak i w czasie trwania kryzysu. Jako podmiot badań zostały wybrane małe i średnie przedsiębiorstwa z terenu Polsce. Zostały postawione dwie hipotezy: • kobiety na stanowiskach menedżerskich, wcześniej niż mężczyźni w takich samych okolicznościach, dostrzegają zbliżający się kryzys i bez zwłoki podejmują działania, • mężczyźni na stanowiskach kierowniczych nie dostrzegają kryzysu w momencie jego zbliżania się, czy już pojawienia się, do czasu, gdy dalsze prowadzenie działalności gospodarczej staje się prawie niemożliwe. Celem utylitarnym pracy jest opracowanie zaleceń metodycznych uwzględniających inne sposoby podejmowania decyzji przez menedżerów obu płci. Do zbadania przedmiotu pracy zostały wybrane badania ilościowe i jakościowe. Te ostatnie podzielono na obserwację uczestniczącą i wywiad pogłębiony. Wyniki badań pozytywnie zweryfikowały obie hipotezy. Badania wykazały również, że menedżerowie mężczyźni przejawiają znacznie większe zdolności do podejmowania decyzji w skrajnie trudnych sytuacjach niż menedżerowie kobiety.

  • Podsumowanie
    • Karolina Krośnicka
    • Katarzyna Zielonko-Jung
    2022

    Zawiera syntezę i ocenę projektów architektoniczno-urbanistycznych Centrum Kompetencji Energetyki Odnawialnej w Rumi i jego otoczenia.

  • Polish tax reform "Polski Ład" – consequences of introducing changes on the example of selected flat-rate tax forms for micro and small companies
    • Piotr Kasprzak
    • Danuta Boike
    • Ewa Łączek-Tarazewicz
    • Jarosław Wróblewski
    2022

    This article describes aspects related to the introduction of the latest tax reform in Poland. The changes initiated in January 2022, under the name Polski Ład, concern a wide range of tax changes in Poland. Reform, in a broad sense, is a multidimensional government development program, which is primarily aimed at getting out of the crisis caused by the COVID-19 pandemic and a smooth transition to financing strategic goals in investment areas. The main aim of the article is to present the most important aspects regarding issues related to the consequences of introducing changes in selected flat-rate tax forms for micro and small companies. The detailed objectives of the article are to present issues that affect the tax records using the tax card, and to show what restrictions are introduced by the Polish order in the tax card records system.

  • POLITECHNIKA GDAŃSKA W LITERATURZE
    • Agnieszka Leszczewicz
    2022 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    W artykule przedstawiono w jaki sposób Politechnika Gdańska funkcjonuje w literaturze pięknej. Politechnika ukazywana jest jako miejsce nauki, ale także miejsce wydarzeń historycznych i kulturalnych, jej istnienie jest zakorzenione w świadomości gdańszczan, a przede jest to miejsce w którym spędziło się najlepiej wspominany okres w życiu – okres studiów i pracy zawodowej. Wymienione zostały publikacje informacyjne, ale przede wszystkim skupiono się na literaturze historycznej, naukowej, wspomnieniach i oczywiście na literaturze obyczajowej. W referacie poświęcono szczególną uwagę Wydziałowi Elektrotechniki i Automatyki.

  • Polscy inżynierowie elektrycy w 1936 r.
    • Dariusz Świsulski
    2022 Wiadomości Elektrotechniczne

    Na podstawie notek biograficznych ponad 1000 osób przedstawiono stan kadry inżynierskiej w zakresie elektrotechniki w 1936 r. Podano uczelnie, w których wykształcenie zdobywali polscy inżynierowie elektrycy. Omówiono liczbę osób z dyplomem inżyniera elektryka zamieszkujących poszczególne rejony przedwojennej Polski. Podano miejsca pracy w różnych dziedzinach działalności inżynierskiej. Omówiono zaangażowanie w działalność Związku Polskich Inżynierów Elektryków oraz liczbę kobiet inżynierów elektryków.

  • Polska gospodarka na tle trendów w globalnych łańcuchach wartości
    • Aleksandra Kordalska
    • Magdalena Olczyk
    2022

    Celem artykułu jest ocena stopnia i charakteru zaangażowania Polski w globalne łańcuchy wartości na tle ogólnoświatowych trendów. Analiza przeprowadzona jest na poziomie całej gospodarki oraz na poziomie jej sekcji i działów. Badanie z użyciem tablic przepływów międzygałęziowych dla lat 2000-2014 wykorzystuje dekompozycję produkcji finalnej i wartości dodanej zaproponowaną przez Wanga i in (2017). Wyniki analizy pokazują, iż zaangażowanie Polski w globalne łańcuchy wartości jest znacząco niższe w porównaniu do krajów Europy Środkowo-Wschodniej. Większą dynamiką wzrostu charakteryzują się powiązania polegające na sprzedaży polskich produktów pośrednich za granicę, niż te dotyczące ich zakupu z zagranicy. Polska dostarcza produkty pośrednie raczej lokalnie niż globalnie. Ponadto wykazano, iż w badanych latach znacząco zwiększa się udział Polski w złożonym handlu wartością dodaną. Analiza na poziomie działów gospodarki wskazuje, że polski przemysł przetwórczy jest sekcją najsilniej angażującą się w globalne łańcuchy wartości, niezależnie od typu powiązania, a udział polskich usług w globalnych sieciach jest nadal niezadawalający.

  • Polydopamine Biomaterials for Skin Regeneration
    • Mohsen Khodadadi Yazdi
    • Mehrak Zare
    • Ali Khodadadi
    • Farzad Seidi
    • S. Mohammad Sajadi
    • Payam Zarrintaj
    • Ahmad Arefi
    • Mohammad Saeb
    • Masoud Mozafari
    2022 ACS Biomaterials Science & Engineering

    Designing biomaterials capable of biomimicking wound healing and skin regeneration has been receiving increasing attention recently. Some biopolymers behave similarly to the extracellular matrix (ECM), supporting biointerfacial adhesion and intrinsic cellular interactions. Polydopamine (PDA) is a natural bioadhesive and bioactive polymer that endows high chemical versatility, making it an exciting candidate for a wide range of biomedical applications. Moreover, biomaterials based on PDA and its derivatives have near-infrared (NIR) absorption, excellent biocompatibility, intrinsic antioxidative activity, antibacterial activity, and cell affinity. PDA can regulate cell behavior by controlling signal transduction pathways. It governs the focal adhesion behavior of cells at the biomaterials interface. These features make melanin-like PDA a fascinating biomaterial for wound healing and skin regeneration. This paper overviews PDA-based biomaterials’ synthesis, properties, and interactions with biological entities. Furthermore, the utilization of PDA nano- and microstructures as a constituent of wound-dressing formulations is highlighted.

  • Poly(hydroxybutyrate-co-hydroxyvalerate) as a biodegradable binder in a negative electrode material for lithium-ion batteries
    • Andrzej Nowak
    • Konrad Trzciński
    • Zuzanna Zarach
    • Jinjin Li
    • Daria Roda
    • Mariusz Szkoda
    2022 Full text APPLIED SURFACE SCIENCE

    In this work, graphite-based negative electrode for lithium-ion battery consisting a novel and biodegradable binder poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is compared with standard graphite electrode with polyvinylidene fluoride (PVDF) as a binder. The rate and cycling performance of lithium ion insertion/extraction of electrodes with PHBV in a half-cell configuration are evaluated. Moreover, on the basis of the electrochemical tests it is concluded that the electrode with PHBV binder is characterized by similar specific capacity and diffusion coefficient of lithium ions as conventional graphite electrode with PVDF binder.

  • Poly-L-Lysine-functionalized fluorescent diamond particles: pH triggered fluorescence enhancement via surface charge modulation
    • Monika Janik
    • Maciej Głowacki
    • Mirosław Sawczak
    • Anna Wcisło
    • Paweł Niedziałkowski
    • Kacper Jurak
    • Mateusz Ficek
    • Robert Bogdanowicz
    2022 Full text MRS BULLETIN

    Recently, the interest in applying fluorescent diamond particles (FDPs) containing nitrogen-vacancy (NV) centers for enhancing the mechanical and chemical properties of some materials, biological imaging, and sensing has been expanding rapidly. The unique properties of NV centers such as intensive, time-stable fluorescence, and an electron spin, which exhibits long coherence time and may be manipulated using external stimuli, such as pH, make them a perfect candidate for a quantum-effect-based sensing platform. However, monitoring of the local changes with the use of the nonmodified diamond particles has certain limitations; therefore, to enhance their sensing properties, in this article, the covalent functionalization of the FDPs’ surfaces with poly-L-Lysine (pLys) (NV-pLys) is presented. The FDPs’ surface is functionalized in an anhydrous environment, and successful attachment is confirmed by Fourier transform infrared spectroscopy (FTIR). As the pLys undergoes pH-triggered changes of conformation, it also induces changes in the diamonds’ surface charge, therefore modulating the fluorescence, and finally as a result enhances NV-pLys pH-sensitivity. Further investigation of the zeta potential, particle size, and contact angle reveals remarkable colloidal stability and superior wettability of the NV-pLys over a wide range of pH, which also may significantly affect NV-pLys biocompatibility. These findings open new possibilities for the construction of biocompatible, stable, and highly sensitive nanosensors.

  • Polylysine for Skin Regeneration: A Review of Recent Advances and Perspectives
    • Payam Zarrintaj
    • Sadegh Ghorbani
    • Mahmood Barani
    • Narendra Pal Singh Chauhan
    • Mohsen Khodadadi Yazdi
    • Mohammad Saeb
    • Joshua D. Ramsey
    • Michael R. Hamblin
    • Masoud Mozafari
    • Ebrahim Mostafavi
    2022 Full text Bioengineering & Translational Medicine

    There have been several attempts to find promising biomaterials for skin regeneration, among which polylysine (a homopolypeptide) has shown benefits in the regeneration and treatment of skin disorders. This class of biomaterials has shown exceptional abilities due to their macromolecular structure. Polylysine-based biomaterials can not only be used as tissue engineering scaffolds for skin regeneration, but also as drug carriers or even gene delivery vectors for the treatment of skin diseases. In addition, polylysine can play a preservative role in extending the lifetime of skin tissue by minimizing the appearance of photodamaged skin. Research on Polylysine is growing today, opening new scenarios that expand the potential of these biomaterials from traditional treatments to a new era of tissue regeneration. This review aims to address the basic concepts, recent trends, and prospects of polylysine-based biomaterials for skin regeneration. Undoubtedly, this class of biomaterials needs further evaluations and explorations, and many critical questions have yet to be answered.

  • Polynomial Algorithm for Minimal (1,2)-Dominating Set in Networks
    • Joanna Raczek
    2022 Full text Electronics

    Dominating sets find application in a variety of networks. A subset of nodes D is a (1,2)-dominating set in a graph G=(V,E) if every node not in D is adjacent to a node in D and is also at most a distance of 2 to another node from D. In networks, (1,2)-dominating sets have a higher fault tolerance and provide a higher reliability of services in case of failure. However, finding such the smallest set is NP-hard. In this paper, we propose a polynomial time algorithm finding a minimal (1,2)-dominating set, Minimal_12_Set. We test the proposed algorithm in network models such as trees, geometric random graphs, random graphs and cubic graphs, and we show that the sets of nodes returned by the Minimal_12_Set are in general smaller than sets consisting of nodes chosen randomly.

  • Polynomial Chaos Expansion in Bio-and Structural Mechanics
    • Katarzyna Szepietowska
    2022

    This monograph presents a probabilistic approach to modelling the mechanics of materials and structures where the modelled performance is influenced by uncertainty in the input parameters. The work is interdisciplinary and the methods described are applied to medical and civil engineering problems. The motivation for this work was the necessity of mechanics-based approaches in the modelling and simulation of implants used in the repair of ventral hernias. Many uncertainties appear in the modelling of the implant-abdominal wall system. The probabilistic approach proposed in this monograph enables these uncertainties to be propagated to the output of the model and the investigation of their respective influences. The regression-based polynomial chaos expansion method is used here. However, the accuracy of such non-intrusive methods depends on the number and location of sampling points. Finding a universal method to achieve a good balance between accuracy and computational cost is still an open question so different approaches are investigated in this monograph in order to choose an efficient method. Global sensitivity analysis is used to investigate the respective influences of input uncertainties on the variation of the outputs of different models. The uncertainties are propagated to the implant-abdominal wall models in order to draw some conclusions important for further research. Using the expertise acquired from biomechanical models, modelling of historic timber joints and simulations of their mechanical behaviour is undertaken. Such an investigation is important owing to the need for efficient planning of repairs and renovation of buildings of historical value.

  • Polysaccharide-based electroconductive hydrogels: Structure, properties and biomedical applications
    • Mohsen Khodadadi Yazdi
    • Payam Zarrintaj
    • Farzad Seidi
    • Mohammad Saeb
    • Masoud Mozafari
    2022 CARBOHYDRATE POLYMERS

    Architecting an appropriate platform for biomedical applications requires setting a balance between simplicity and complexity. Polysaccharides (PSAs) play essential roles in our life in food resources, structural materials, and energy storage capacitors. Moreover, the diversity and abundance of PSAs have made them an indispensable part of food ingredients and cosmetics. PSA-based hydrogels have been extensively reviewed in biomedical applications. These hydrogels can be designed in different forms to show optimum performance. For instance, electroactive PSA-based hydrogels respond under an electric stimulus. Such performance can be served in stimulus drug release and determining cell fate. This review classifies and discusses the structure, properties, and applications of the most important polysaccharide-based electroactive hydrogels (agarose, alginate, chitosan, cellulose, and dextran) in medicine, focusing on their usage in tissue engineering, flexible electronics, and drug delivery applications.

  • Polysaccharide-based Nanocomposites for Biomedical Applications: A Critical Review
    • Hanieh Shokrani
    • Amirhossein Shokrani
    • S. Mohammad Sajadi
    • Mohsen Khodadadi Yazdi
    • Farzad Seidi
    • Maryam Jouyandeh
    • Payam Zarrintaj
    • Saptarshi Kar
    • Seokjhin Kim
    • Tairong Kuang
    • Navid Rabiee
    • Aleksander Hejna
    • Mohammad Saeb
    • Seeram Ramakrishna
    2022 Full text Nanoscale Horizons

    Polysaccharides (PSA) are taking specific position among biomaterials for advanced applications in medicine. Nevertheless, poor mechanical properties is known as the main drawback of PSA, which highlights need for PSA modification. Nanocomposites PSA (NPSA) are a class of biomaterials widely used as biomedical platforms, but despite their importance and worldwide use have not been reviewed. Herein we critically reviewed application of NPSA by categorizing them into generic and advanced application realms. First, application of NPSA as drug and gene delivery systems, along with their role in the field as antibacterial platform and hemostasis agent is discussed. Then, applications of NPSA for skin, bone, nerve, and cartilage tissue engineering are highlighted, followed by cell encapsulation and more critically cancer diagnosis and treatment potentials. In particular, three features of investigations devoted to cancer, i.e. radiotherapy, immunotherapy, and photothermal therapy, are comprehensively reviewed and discussed. Since this field experience an early-stage maturity, some other aspects such as bioimaging and biosensing are reviewed in order to give a sensation of potential applications of NPSA for future developments—providing a support for clinical applications. It is well-documented that using nanoparticles/nanomaterials above a critical concentration brings about concerns to toxicity, so that their effect on cellular interactions would become a criticism. We compared nanoparticles used in fabrication of NPSA in terms of toxicity mechanism to shed more lights on future challenging aspects of NPSA development. Indeed, neutralization mechanisms underlying cytotoxicity of nanomaterials, which are expected to be induced by polysaccharide introduction, should be taken into account for future investigations.

  • Polysaccharides in fabrication of membranes: A review
    • Vahid Vatanpour
    • Michael Badawi
    • Mohammad Saeb
    2022 CARBOHYDRATE POLYMERS

    Sustainability concerns have motivated and directed a great deal of interest over the past decade towards the development of green technologies. Polysaccharides are green polymers, which experienced growing demand to substitute chemically synthetic polymers. Different types of polysaccharides i.e. cellulose-, starch-, chitin- alginate-, and chitosan-based carbohydrate polymers have been applied in the fabrication of separation membranes. The purpose of the current review was to summarize, classify, and discuss the state-of-the-art the fabrication of membranes with carbohydrate polymers. Specific attention was paid to highlight the strategies used in the successful development of such membranes. First, a brief review of different types of polysaccharides was performed. Next, the application of these polysaccharides in the fabrication of liquid filtration, gas separation, adsorption, pervaporation and proton exchange membranes were comprehensively reviewed. Computational evaluations were also reviewed. Eventually, concluding remarks together with challenging aspects of the future perspective over application of polysaccharide membranes were discussed.

  • Polyurethane based hybrid ciprofloxacin-releasing wound dressings designed for skin engineering purpose
    • Iga Carayon
    • Paweł Szarlej
    • Przemysław Gnatowski
    • Edyta Piłat
    • Maciej Sienkiewicz
    • Marta Glinka
    • Jakub Karczewski
    • Justyna Kucińska-Lipka
    2022 Full text Advances in Medical Sciences

    Purpose Even in the 21st century, chronic wounds still pose a major challenge due to potentially inappropriate treatment options, so the latest wound dressings are hybrid systems that enable clinical management, such as a hybrid of hydrogels, antibiotics and polymers. These wound dressings are mainly used for chronic and complex wounds, which can easily be infected by bacteria. Materials and methods Six Composite Porous Matrices (CPMs) based on polyurethane (PUR) in alliance with polylactide (PLAs) and poly(vinyl alcohol) (PVA) were prepared and analyzed using optical microscopy. Three different types of hydrogels and their Ciprofloxacin (Cipro) modified variants’ ratios were prepared and analyzed using FTIR, SEM and EDX techniques. Six Hybrid Cipro-Releasing Hydrogel Wound Dressings (H-CRWDs) were also prepared and underwent short-term degradation, Cipro release, microbiology and cell viability measurements. Results Average porosity of CPMs was in the range of 69–81%. The pore size of the obtained CPMs was optimal for skin regeneration. Short-term degradation studies revealed degradability in physiological conditions regardless of sample type. A meaningful release was also observed even in short time (21.76 ​± ​0.64 ​μg/mL after 15 ​min). Microbiological tests showed visible inhibition zones. Cell viability tests proved that the obtained H-CRWDs were biocompatible (over 85% of cells). Conclusions A promising hybrid wound dressing was labeled. Simple and cost-effective methods were used to obtain microbiologically active and biocompatible dressings. The results were of importance for the design and development of acceptable solutions in the management of chronic wounds of high potential for infection.

  • Pomiar impedancji pętli zwarciowej w instalacjach fotowoltaicznych dużych mocy z magazynowaniem energii
    • Jacek Katarzyński
    • Jakub Olesz
    2022 Full text Przegląd Elektrotechniczny

    W artykule przedstawiono różne konfiguracje przepływu energii w instalacjach fotowoltaicznych z zastosowaniem przekształtników energoelektronicznych o mocy od 10 do 1000 kVA. W pomiarach impedancji pętli zwarciowej (IPZ) w obwodach zasilanych z przekształtników przyrządami różnych producentów zaobserwowano wyniki pomiaru zależne od trybu pracy przekształtnika oraz od wartości wymuszanego prądu probierczego przyrządu. W artykule wskazano na właściwą metodologię pomiaru IPZ w instalacjach fotowoltaicznych z użyciem przekształtników energoelektronicznych z magazynowaniem energii.

  • Pomiar impedancji pętli zwarciowej w obwodach z wyłącznikami różnicowoprądowymi selektywnymi
    • Kornel Borowski
    • Stanisław Czapp
    2022

    Pomiar impedancji pętli zwarciowej w obwodach z wyłącznikami różnicowoprądowymi bezzwłocznymi jest kłopotliwy, ponieważ przy stosowaniu typowych mierników o prądzie pomiarowym rzędu 10-20 A zwykle następują zbędne zadziałania tych zabezpieczeń. W przypadku obwodów z wyłącznikami różnicowoprądowymi selektywnymi jest inaczej. W referacie wykazano, że pomiar ten można wykonać nawet miernikiem wielkoprądowym wymuszającym prąd o wartości szczytowej około 200 A. Przedstawiono przykładowe oscylogramy prądu pomiarowego oraz wyniki badań reakcji wyłączników różnicowoprądowych na pomiar impedancji pętli zwarciowej.

  • Pomorski Archipelag Wysp Energetycznych
    • Andrzej Szajner
    • Paweł Bućko
    • Katarzyna Grecka
    2022 Zeszyty Problemowe Samorząd Pomorza

    Omówiono możliwy rozwój energetyki prosumenckiej na terenie województwa pomorskiego. Odniesiono się do form organizacyjnych oraz współpracy lokalnych struktur z systemem elektroenergetycznym.

  • Pompownie dużej mocy z falownikiem wędrującym średniego napięcia
    • Dariusz Karkosiński
    2022 Automatyka Elektryka Zakłócenia

    Artykuł zawiera rys rozwoju napędów przekształtnikowych w stacjach pomp, w szczególności regulacji wydatku kilku pomp, po kolei, przez jeden przemiennik częstotliwości. Omówiono podstawy teoretyczne zjawiska pola niestłumionego i napięcia resztkowego silników, które utrudniają szybkie przełączania silnika pompy pomiędzy zasilaniem regulowanym przez falownik a zasilaniem z sieci. Przedstawiono zasady transferu (przełączania) synchronicznego pozwalające na minimalizację kosztów inwestycji poprzez konfigurowanie jednego przemiennika częstotliwości średniego napięcia, jako falownika wędrującego, do efektywnej regulacji kilku pomp dużej mocy w pompowni cieczy. Opracowano konfigurację sprzętową krajowej klasycznej - nie specjalizowanej przez wytwórcę falownika, rozdzielnicy SN z wieloma polami silnikowymi. Wykazano, że zaproponowane rozwiązanie jest ekonomiczne uzasadnione w pompowniach o większej liczbie pomp.

  • Porous Phantoms Mimicking Tissues – Investigation of Optical Parameter Stability Over Time
    • Monika Ronowska
    2022 Full text

    In terms of optical parameters, optical phantoms can now replace live tissues and be used to validate optical measurement methods. Therefore, whether these parameters would be maintained after storage for 6 months was examined. The absorption and scattering coefficients were obtained from the measured transmittance and reflectance measurements taken 6 months apart and then compared. All of the measurements were conducted using the same experimental setup consisting of an integrating sphere, a light source with a wavelength of 635 nm and a detector. The optical phantoms on which the research was performed were prepared from silicone and glycerol in various proportions.

  • PORÓWNANIE DZIAŁANIA POPRZECZNYCH ŁOŻYSK ŚLIZGOWYCH NA ZMODERNIZOWANYM STANOWISKU DYDAKTYCZNYM
    • Piotr Bzura
    • Jakub Kowalski
    2022 Full text Journal of Polish CIMEEAC

    W artykule przedstawiono autorską metodę porównania działania poprzecznych łożysk ślizgowych na podstawie wyników badań wykonanych na zmodernizowanym stanowisku laboratoryjnym. Modernizacja stanowiska składającego się ze źródła mocy w postaci silnika elektrycznego napędzającego dwa wały połączone sprzęgłem i zakończone łożyskiem wzdłużnym przekazującym siłę naporu. Podłączenie przetwornika częstotliwości umożliwiło pracę silnika elektrycznego przy różnych prędkościach obrotowych i stałym momencie obrotowym. Na podstawie analizy przeprowadzonych badań został przedstawiony algorytm, według którego porównano ze względu na kierunek i prędkość obrotów oraz sposób smarowania poprzeczne łożyska ślizgowe posadowione na pierwszym wale między silnikiem a łożyskiem oporowym.

  • Porównanie OpenStack Networking z innymi rozwiązaniami chmurowymi
    • Ewelina Kamyszek
    • Krzysztof Gierłowski
    • Jan M. Kelner
    2022 Elektronika : konstrukcje, technologie, zastosowania

    W dzisiejszych czasach coraz więcej firm decyduje się na uruchamianie usług oraz przetwarzanie danych w ramach tak zwanych systemów chmurowych, których przykładem może być m.in. OpenStack. Szeroka gama istniejących rozwiązań pozwala na dostosowanie chmury do potrzeb i wymagań użytkownika. Podczas wyboru systemu chmurowego jednym z ważniejszych aspektów jest analiza oferowanych przez niego mechanizmów oraz zaawansowanych usług sieciowych. Poniższy artykuł zawiera podstawowe informacje dotyczące chmury obliczeniowej, najpopularniejszych modułów wykorzystywanych do wdrożenia chmury OpenStack wraz z omówieniem architektury modułu sieciowego OpenStack Networking. Ponadto, przedstawiono porównanie mechanizmów i usług sieciowych oferowanych przez system OpenStack oraz dwa inne systemy chmurowe, tj. Amazon Web Services oraz Apache CloudStack.

  • Portico Farmhouses of the Vistula Delta: Architecture, Current State and Finite Element Modelling of Timber Roof Truss under Material and Cross-section Uncertainty
    • Tomasz Zybała
    • Katarzyna Szepietowska
    • Grzegorz Bukal
    • Izabela Lubowiecka
    2022 Full text International Journal of Architectural Heritage

    The article focuses on the oldest surviving I-type portico houses located in the Vistula Delta, which were built in the 17th and 18th centuries. The study describes the houses’ origins, structure, details of roof structures and technical condition, and it also includes numerical modelling of a roof truss and its mechanical analysis. Numerical models of the roof trusses are defined and analysed by means of the finite element method. Global sensitivity analysis with the use of the polynomial chaos expansion method is used to study the influence of uncertainties in material properties of wood, such as Young’s modulus and the friction coefficient, and also the beam cross-sectional height in the output of the numerical model of the structure. The outcomes show that the uncertainty of beam height exerts the dominating influence on the maximum deflection of the roof truss, hence accurate measurements of geometry are of great importance in the planning of conservation and renovation of such historic structures.

  • Position Estimation in Mixed Indoor-Outdoor Environment Using Signals of Opportunity and Deep Learning Approach
    • Sebastian Urwan
    • Dominika Wysocka
    • Alicja Pietrzak
    • Krzysztof Cwalina
    2022 Full text International Journal of Electronics and Telecommunications

    To improve the user's localization estimation in indoor and outdoor environment a novel radiolocalization system using deep learning dedicated to work both in indoor and outdoor environment is proposed. It is based on the radio signatures using radio signals of opportunity from LTE an WiFi networks. The measurements of channel state estimators from LTE network and from WiFi network are taken by using the developed application. The user's position is calculated with a trained neural network system's models. Additionally the influence of various number of measurements from LTE and WiFi networks in the input vector on the positioning accuracy was examined. From the results it can be seen that using hybrid deep learning algorithm with a radio signatures method can result in localization error 24.3 m and 1.9 m lower comparing respectively to the GPS system and standalone deep learning algorithm with a radio signatures method in indoor environment. What is more, the combination of LTE and WiFi signals measurement in an input vector results in better indoor and outdoor as well as floor classification accuracy and less positioning error comparing to the input vector consisting measurements from only LTE network or from only WiFi network.

  • Position in global value chains and wages in Central and Eastern European countries
    • Sabina Szymczak
    • Aleksandra Parteka
    • Joanna Wolszczak-Derlacz
    2022 Full text EUROPEAN JOURNAL OF INDUSTRIAL RELATIONS

    This paper examines the relationship between the relative position of industries in Global Value Chains (GVC) and wages in 10 Central and Eastern European countries. We combine GVC measures of global import intensity of production, upstreamness and the length of the value chain with micro-data on workers. We find that the wages of Central and Eastern European countries workers are higher when their industry is at the beginning of the chain or at the end than in the middle. Secondly, wage changes depend on the interplay between upstreamness and GVC intensity. In sectors close to final demand, greater production fragmentation is associated with lower wages.

  • Possible quadrupole-order-driven commensurate-incommensurate phase transition in B20 CoGe
    • S.-H. Baek
    • Vladimir Sidorov
    • A. V. Nikolaev
    • Tomasz Klimczuk
    • Filip Ronning
    • A. V. Tsvyashchenko
    2022 PHYSICAL REVIEW B

    The B20-type cobalt germanide CoGe was investigated by measuring the specific heat, resistivity, and 59Co nuclear magnetic resonance (NMR).We observed a phase transition at TQ = 13.7 K, evidenced by a very narrow peak of the specific heat and sharp changes of the nuclear spin-spin (T −1 2 ) and spin-lattice (T −1 1 ) relaxation rates. The fact that the entropy release is extremely small and the Knight shift is almost independent of temperature down to low temperatures as anticipated in a paramagnetic metal indicates that the TQ transition is of nonmagnetic origin. In addition, we detected a crossover scale T0 ∼ 30 K below which the resistivity and the NMR linewidth increase, and T −1 1 is progressively distributed in space, that is, a static and dynamical spatial inhomogeneity develops. While the order parameter for the TQ transition remains an open question, a group-theoretical analysis suggests that the finite electric quadrupole density arising from the low local site symmetry at cobalt sites could drive the crystal symmetry lowering from the P213 symmetry that is commensurate to the R3 symmetry with an incommensurate wave vector, which fairly well accounts for the TQ transition. The quadrupole-order-driven commensurate-incommensurate phase transition may be another remarkable phenomenon arising from the structural chirality inherent in the noncentrosymmetric B20 family.

  • Potential Energy Curves of Diatomic Alkali Molecules Datasets
    • Patryk Jasik
    • Tymon Kilich
    2022 Full text

    The datasets described in this article contain potential energy curves for several diatomic systems. The data was obtained via high-performance computing using MOLPRO, a system of ab initio programs for advanced molecular electronic structure calculations. The datasets allow to model bond lengths, energy levels, spectra and time-evolution of molecular dimers for which the data are presented.

  • Potential of Functionalized Polyolefins in a Sustainable Polymer Economy: Synthetic Strategies and Applications
    • Lidia Jasińska-Walc
    • Rob Duchateau
    • Miloud Bouyahyi
    2022 ACCOUNTS OF CHEMICAL RESEARCH

    Polymers play a crucial role in our modern life as no other material exists that is so versatile, moldable, and lightweight. Consequently, the demand for polymers will continue to grow with the human population, modernization, and technological developments. However, depleted fossil resources, increasing plastic waste production, ocean pollution, and related growing emission of greenhouse gases has led to a change in the way we think about the use of polymers. Although polymers were never designed to be recycled, it is clear that a linear polymers economy is no longer sustainable. The design for recycling and reuse and life-cycle analyses will become increasingly important factors when deciding on which polymer to choose for a certain application. Of all polymers, polyolefins have the lowest life-cycle environmental impact and even outperform renewable polymers. However, polyolefins are chemically inert and reveal a low surface energy. Combining their excellent mechanical properties with the ability to adhere to other materials or create self-assembled or nanostructured materials would widen the application window of polyolefins even more.

  • Potential of nanocomposites of zero valent copper and magnetite with Eleocharis dulcis biochar for packed column and batch scale removal of Congo red dye
    • Muhammad Imran
    • A Natasha
    • Behzad Murtaza
    • Sabah Ansar
    • Noor S. Shah
    • Zia Ul Haq Khan
    • Ali Shahid
    • Grzegorz Boczkaj
    • Farhan Hafeez
    • Ali Shafaqat
    • Muhammad Rizwan
    2022 ENVIRONMENTAL POLLUTION

    The current study is the first attempt to prepare nanocomposites of Eleocharis dulcis biochar (EDB) with nano zero-valent Copper (nZVCu/EDB) and magnetite nanoparticles (MNPs/EDB) for batch and column scale sequestration of Congo Red dye (CR) from synthetic and natural water. The adsorbents were characterized with advanced analytical techniques. The impact of EDB, MNPs/EDB and nZVCu/EDB dosage (1–4 g/L), pH (4–10), initial concentration of CR (20–500 mg/L), interaction time (180 min) and material type to remove CR from water was examined at ambient temperature. The CR removal followed sequence of nZVCu/EDB > MNPs/EDB > EDB (84.9–98% > 77–95% > 69.5–93%) at dosage 2 g/L when CR concentration was increased from 20 to 500 mg/L. The MNPs/EDB and nZVCu/EDB showed 10.9% and 20.1% higher CR removal than EDB. The adsorption capacity of nZVCu/EDB, MNPs/EDB and EDB was 212, 193 and 174 mg/g, respectively. Freundlich model proved more suitable for sorption experiments while pseudo 2nd order kinetic model well explained the adsorption kinetics. Fixed bed column scale results revealed excellent retention of CR (99%) even at 500 mg/L till 2 h when packed column was filled with 3.0 g nZVCu/EDB, MNPs/EDB and EDB. These results revealed that nanocomposites with biochar can be applied efficiently for the decontamination of CR contaminated water.

  • Potentiometric sensor containing set of ion selective electrodes with lipid modified membranes for quality assessment of tested non-alcoholic beverages
    • Maria Szpakowska
    • Jakub Szwacki
    • Ewa Marjańska
    2022 Full text Desalination and Water Treatment

    Potentiometric sensors may be a good tool for fast quality control of commercial drinks. In this work, such a sensor, containing a set of ion-selective electrodes with lipid-modified membranes (benzylhexadecyldimethylammonium chloride monohydrate, hexadecylamine, 1-dodecanol, elaidic acid, cholesterol) was used for discrimination and quality control of non-alcoholic beverages, mainly composed of sugar and citric acid. It was found that the electrodes stability, membrane reproducibility and sensitivity to acetic, hydrochloric and citric acid concentration were very good. On the contrary, ion selective electrodes were not sensitive to sweet substances (glucose, fructose, sucrose) concentration changes. The potentiometric sensor consisting of ion-selective electrodes was applied to commercially available non-alcoholic beverages, a reference drink and to di-component mixtures of sucrose and citric acid. A database of its responses to those mixtures was created. The possibility of using a “fingerprint” method for recognition and quality control of unknown beverages was discussed. The sensor responses to non-alcoholic beverages were transformed by principal component analysis and agglomerative hierarchical clustering analysis and compared to the results obtained with sensory analysis. The tested drinks can be divided into two groups of similar sour taste intensity (lemonades and orangeades). The beverage of low sour taste intensity and the non-carbonated drink were outside these groups. The obtained results show that the potentiometric sensor with lipid-modified ion-selective electrodes may be a useful tool for quality control of unknown drinks on the last step of a production line.

  • Potyczki algorytmiczne, czyli Alicja i Bogdan w nowych sytuacjach. Alicja i Bogdan w naleśnikarni
    • Marek Kubale
    2022 Pismo PG

    Niniejszym esejem inaugurujemy , po kilkuletniej przerwie, nową serię zagadek algorytmicznych.Pierwszy odcinek nosi nazwę Alicja i Bogdan w naleśnikarni.

  • Pounding between high-rise buildings with different structural arrangements
    • Mahmoud Miari
    • Robert Jankowski
    2022

    Earthquake-induced structural pounding has led to significant damages during previous earthquakes. This paper investigates the effect of pounding on the dynamic response of colliding high-rise buildings with different structural arrangements. Three 3-D buildings are considered in the study, including 5-storey building, 7-storey building and 9-storey building. Three pounding scenarios are also taken into account, i.e. pounding between 5-storey and 7-storey buildings, pounding between 5-storey and 9-storey buildings and pounding between 7-storey and 9-storey buildings. These three pounding scenarios are studied and compared with the no pounding case. The results show that the level of accelerations of colliding buildings significantly increases for all scenarios, as compared to the no pounding case. At the same time, displacements experience both increase and decrease, while the peak storey shears experience an increase due to pounding with few exceptions regarding the top storeys. Finally, pounding leads to the generation of dangerous impact forces with higher peak values experienced in taller buildings.

  • Power Converter Solutions for Industrial PV Applications—A Review
    • Ievgen Verbytskyi
    • Mykola Lukianov
    • Kawsar Nassereddine
    • Bohdan Pakhaliuk
    • Oleksandr Husev
    • Ryszard Strzelecki
    2022 Full text ENERGIES

    : As the use of photovoltaics becomes more widespread, new technologies for more efficient energy generation, transmission, and distribution based on power electronics converters are being developed. The most common applications are grid-on, energy storage, hybrid, and high voltage gain applications. These applications impose several additional requirements in the design of power converters associated with the solar battery’s maximum power tracking and operation in a wide range of input currents and voltages. The practical realization of such solutions can be implemented on the basis of various topologies, which requires a preliminary application of criteria for assessing their effectiveness. The paper conducts a comparison of different topologies on power converters based on two parameters that describe their cost and power loss for various PV applications. For a straightforward study, these parameters are represented using the gain factor, which allows for an accurate comparison of the efficiency of various types of converters.

  • Power efficient thrust allocation algorithms in design of dynamically positioned ships
    • Agnieszka Piekło
    • Anna Witkowska
    • Tomasz Zubowicz
    2022

    Assessment of power consumption on a Dynamically Positioned (DP) ship in the early design stage can assist crucial design choices. The study presents a comparison between two algorithms of optimal thrust allocation in a propulsion system for an over-actuated DP ship. Applied algorithms were Quadratic Programming (QP) and Non- dominated Sorting Genetic Algorithm II (NSGAII). Based on both approaches, tools were developed for ship design purposes. Based on a case study, QP optimization is more suited for universal use and fast analysis of many designs. With adequate optimization of NSGAII parameters, this algorithm can be effective for DP simulations at specified weather conditions. This is due to the possibility of application of original functions describing the DP problem, which is not possible in the case of QP optimization, where the problem needs to be simplified

  • Power Hardware-In-the-Loop Approach for Autonomous Power Generation System Analysis
    • Szymon Racewicz
    • Filip Kutt
    • Łukasz Sienkiewicz
    2022 Full text ENERGIES

    The article presents the Power Hardware-In-the-Loop (PHIL) dynamic model of a synchronous generator of 125 kVA for autonomous power generation system analysis. This type of system is typically composed of electrical energy sources in the form of several diesel generator units with synchronous machines, the main distribution switchboard and different loads. In modern power distribution systems, the proposed power management strategies are typically aimed at the minimization of fuel consumption by maintaining the operation of diesel generator units at peak efficiency. In order to design and test such a system in conditions as close as possible to the real operating conditions, without constructing an actual power distribution system, a PHIL model in the form of a power inverter that emulates the behaviour of a real synchronous generator is proposed. The PHIL model was prepared in the MATLAB/Simulink environment, compiled to the C language and fed into a 150 kVA bidirectional DC/AC commercial-grade converter driven by a HIL real-time simulation control unit. Experimental research was performed in the LINTE2 laboratory of the Gdańsk University of Technology (Poland), where the PHIL emulator was developed. The proposed model was validated by comparing the output voltages and currents as well as an excitation current with the measurements performed on the 125 kVA synchronous generator. The obtained results proved satisfactory compliance of the PHIL model with its real counterpart.

  • Powłoki malarskie w ochronie przeciwkorozyjnej. Zasady stosowania i kontrola jakości
    • Andrzej Miszczyk
    • Michał Szociński
    • Kazimierz Darowicki
    2022

    W książce przedstawiono podstawowe zasady wykonywania i kontroli jakości przeciwkorozyjnych wymalowań malarskich na konstrukcjach stalowych. Opracowanie powstało na bazie wykładów i zajęć praktycznych dla studentów Wydziału Chemicznego Politechniki Gdańskiej prowadzonych przez Katedrę Elektrochemii, Korozji i Inżynierii Materiałowej oraz realizowanych w ramach prac Katedry od około 12 lat kursów dla inspektorów powłok malarskich. Dotyczą one nadzoru wykonywania zabezpieczeń powłokowych na statkach morskich, w szczególności w zbiornikach balastowych. Kursy te są certyfikowane przez firmę DNV z siedzibą w Høvik w Norwegii, będącą znanym, międzynarodowym, akredytowanym towarzystwem klasyfikacyjnym. Prezentowane zasady omówiono na przykładzie konstrukcji morskich, jednak obowiązują one w przypadku każdej konstrukcji stalowej. Przedstawione w książce wymagania stawiane wykonawcom prezentują – zgodnie z obecnym stanem wiedzy i doświadczeń – optymalny poziom pod względem trwałości zabezpieczenia przeciwkorozyjnego. Książka została zaopatrzona w spis norm oraz słowniki terminów specjalistycznych: angielsko-niemiecko-polski i polsko-angielsko-niemiecki.

  • Powojenny rozdział w historii architektury i zagospodarowania portu gdyńskiego
    • Anna Orchowska-Smolińska
    2022

    The port of Gdynia, considered one of the largest civil construction projects of the 20th century in Europe, was built at an express pace for only a dozen or so years from the mid-1920s to the end of the 1930s. Unusual solutions from the construction period in the port engineering category, as well as outstanding architectural works The industrial area quickly became architectural symbols of economic growth and the general rebirth of Poland after 1918. In April 1945, the Poles took over the property of the port after the war found a picture of the ruins and destruction of the port, mainly the result of deliberate plantings carried out on the orders of Adolf Hitler in the last 10 days before the capitulation of the Germans. The devastation of individual elements of the port infrastructure and buildings was assessed at the level from 25% to 100%. Post-war reconstruction of the port from damage, in the years 1945-1947 not only the losses were inventoried, but also significant decisions were made as to whether the building was to be rebuilt or a new investment was planned in its place. Studies on this subject show that the investment reconstruction of the port did not continue the boldly outlined pre-war development plans, but from the point of view of its architecture, a new page in its history definitely opened up for this industrial complex.

  • Prace doktorskie, habilitacje oraz profesury o tematyce chemii analitycznej i pokrewnej w 2021 r.
    • Marek Biziuk
    • Żaneta Polkowska
    2022 Analityka: Nauka i Praktyka

    Publikacja zawiera zestawienie prac doktorskich, habilitacji oraz profesur o tematyce chemii analitycznej i pokrewnej w 2021 r.,

  • Praseodymium Orthoniobate and Praseodymium Substituted Lanthanum Orthoniobate: Electrical and Structural Properties
    • Kacper Dzierzgowski
    • Sebastian Wachowski
    • Marcin Łapiński
    • Aleksandra Mielewczyk-Gryń
    • Maria Gazda
    2022 Full text Materials

    In this paper, the structural properties and the electrical conductivity of La1−xPrxNbO4+δ (x = 0.00, 0.05, 0.1, 0.15, 0.2, 0.3) and PrNbO4+δ are presented and discussed. All synthesized samples crystallized in a monoclinic structure with similar thermal expansion coefficients. The phase transition temperature between the monoclinic and tetragonal structure increases with increasing praseodymium content from 500 ◦C for undoped LaNbO4+δ to 700 ◦C for PrNbO4+δ. Thermogravimetry, along with X-ray photoelectron spectroscopy, confirmed a mixed 3+/4+ oxidation state of praseodymium. All studied materials, in humid air, exhibited mixed protonic, oxygen ionic and hole conductivity. The highest total conductivity was measured in dry air at 700 ◦C for PrNbO4+δ, and its value was 1.4 · 10−3 S/cm.

  • Precipitation of calcium carbonate in the presence of rhamnolipids in alginate hydrogels as a model of biomineralization
    • Natalia Czaplicka
    • Donata Konopacka-Łyskawa
    • Agata Nowotnik
    • Aleksandra Mielewczyk-Gryń
    • Marcin Łapiński
    • Rafał Bray
    2022 Full text COLLOIDS AND SURFACES B-BIOINTERFACES

    This paper reports the effects of rhamnolipids presence in the alginate hydrogel and CO32- solution, on the precipitation of CaCO3 in the Ca2+ loaded alginate hydrogel. Characteristics of the formed particles are discussed. Model conditions containing alginate hydrogel and rhamnolipids were used in order to mimic the natural environment of biomineralization in biofilms. It has been shown that rhamnolipids affect the characteristics of precipitated calcium carbonate effect of using these biosurfactants depends on their concentration as well as whether they are directly present in the hydrogel matrix or the carbonate solution surrounding the hydrogel. The greatest effect compared to the control samples was found for the rhamnolipids in the form of micelles directly present in the hydrogel with the CaCl2 cross-linked solution at concentration of 0.05 M. These conditions result in the highest increase in vaterite content, specific surface area, and pore volume. The mechanism of CaCO3 precipitation in alginate hydrogel containing rhamnolipids has been proposed.

  • Precypitacja węglanu wapnia metodą karbonatyzacji z dodatkiem glicerolu w obecności wybranych promotorów absorpcji CO2
    • Natalia Czaplicka
    • Donata Konopacka-Łyskawa
    • Barbara Kościelska
    • Marcin Łapiński
    2022

    Jednym ze sposobów produkcji węglanu wapnia jest metoda gaz-ciecz, w której jako reagent stosuje się gazowy CO2 oraz roztwór soli wapnia, do którego dodawane są związki sprzyjające absorpcji CO2, tzw. promotory. Reakcja z gazowym CO2 jest specyficzna, ponieważ powstawanie jonów wodorowęglanowych podczas absorpcji CO2 z reakcją chemiczną jest etapem decydującym o szybkości procesu strącania CaCO3. Celem niniejszej pracy było określenie wpływu glicerolu na przebieg wytrącania CaCO3 oraz charakterystykę wytworzonych cząstek metodą karbonatyzacji. Proces prowadzono w temperaturze pokojowej pod ciśnieniem atmosferycznym w reaktorze typu gas(CO2)-lift z cyrkulacją wewnętrzną. Mieszaninę reakcyjną stanowił roztwór CaCl2 zawierający 0, 5 lub 10% (obj.) glicerolu oraz promotor absorpcji CO2 w postaci amoniaku lub trietanoloaminy (TEA). Otrzymaną zawiesinę cząstek CaCO3 podzielono na dwie części. Pierwszą porcję przesączono natychmiast po zakończeniu reakcji, natomiast drugą rozdzielono po 1 godzinie. W celu scharakteryzowania otrzymanych cząstek określono ich skład polimorficzny, powierzchnię właściwą oraz morfologię. Największą powierzchnię właściwą miały próbki otrzymane w roztworach zawierających NH3, co jest skorelowane z zawartością waterytu. Dodatek glicerolu do mieszaniny reakcyjnej wpływa na szybkość absorpcji CO2 do układu oraz na szybkość dyfuzji jonów w mieszaninie reakcyjnej. Zatem im wyższe stężenie glicerolu tym dłuższy czas reakcji strącania. Ponadto dla zastosowanych stężeń glicerolu nie obserwowano stabilizacji metastabilnego waterytu.

  • Predicting Ice Phenomena in a River Using the Artificial Neural Network and Extreme Gradient Boosting
    • Renata Graf
    • Tomasz Kolerski
    • Senlin Zhu
    2022 Full text Resources-Basel

    Forecasting ice phenomena in river systems is of great importance because these phenomena are a fundamental part of the hydrological regime. Due to the stochasticity of ice phenomena, their prediction is a difficult process, especially when data sets are sparse or incomplete. In this study, two machine learning models—Multilayer Perceptron Neural Network (MLPNN) and Extreme Gradient Boosting (XGBoost)—were developed to predict ice phenomena in the Warta River in Poland in a temperate climate zone. Observational data from eight river gauges during the period 1983–2013 were used. The performance of the model was evaluated using four model fit measures. The results showed that the choice of input variables influenced the accuracy of the developed models. The most important predictors were the nature of phenomena on the day before an observation, as well as water and air temperatures; river flow and water level were less important for predicting the formation of ice phenomena. The modeling results showed that both MLPNN and XGBoost provided promising results for the prediction of ice phenomena. The research results of the present study could also be useful for predicting ice phenomena in other regions.

  • Prediction of Bioactive Peptides From Chicken Feather and Pig Hair Keratins Using In Silico Analysis Based on Fragmentomic Approach
    • Antoni Taraszkiewicz
    • Izabela Sinkiewicz
    • Agata Sommer
    • Małgorzata Dąbrowska
    • Hanna Staroszczyk
    2022 Full text CURRENT PHARMACEUTICAL DESIGN

    Background: Keratin is among the most abundant structural proteins of animal origin, however it remains broadly underutilized. Objective: Bioinformatic investigation was performed to evaluate selected keratins originating from mass-produced waste products, i.e., chicken feathers and pig hair, as potential sources of bioactive peptides. Methods: Pepsin, trypsin, chymotrypsin, papain, and subtilisin were used for in silico keratinolysis with the use of “Enzyme(s) action” and fragmentomic analysis of theoretical products was performed using “Profiles of potential biological activity” in BIOPEP-UWM database of bioactive peptides. Bioactivity probability calculation and toxicity prediction of the peptides obtained were estimated using PeptideRanker and ToxinPred tools, respectively. Results: Our results showed that the keratins are a potential source of a variety of biopeptides, including dipeptidyl peptidase IV, angiotensin converting enzyme, prolyl endopeptidase inhibitory and antioxidative. Papain and subtilisin were found to be the most appropriate enzymes for keratin hydrolysis. This study presents possible structures of keratin-derived bioactive peptides that have not been previously described. Conclusion: Our data suggest additional in vitro and in vivo studies to verify theoretical predictions and further investigate the possibility of using keratin-rich waste as a source of peptide nutraceuticals.

  • Prediction of fracture toughness in fibre-reinforced concrete, mortar, and rocks using various Machine learning techniques
    • Arash Dehestani
    • Farzin Kazemi
    • Rezvan Abdi
    • Michał Nitka
    2022 ENGINEERING FRACTURE MECHANICS

    Machine Learning (ML) method is widely used in engineering applications such as fracture mechanics. In this study, twenty different ML algorithms were employed and compared for the prediction of the fracture toughness and fracture load in modes I, II, and mixed-mode (I-II) of various materials, including fibre-reinforced concrete, cement mortar, sandstone, white travertine, marble, and granite. A set of 401 specimens of “Brazilian discs with central cracks” were used as a training and testing dataset. The main features of the experimental technique in each specimen are the fracture mode, the tensile strength of the specimen, the inclination of the crack with loading direction, the thickness of specimens and the half-length of the crack. The improved ML algorithms were implemented using Python programming language. The results of the coefficient of restitution (R2) and statistical metrics confirm that the ML algorithms are able to predict the fracture toughness and fracture load in modes I, II, and mixed-mode (I-II) with high accuracy. To validate the reliability of the proposed ML-based prediction models, three experimental tests were used. Moreover, the Graphical User Interface (GUI) of the ML-based models is created as a practical tool for estimating the fracture load and fracture toughness for engineering problems.

  • Prediction of Pile Shaft Capacity in Tension Based on Some Direct CPT Methods—Vistula Marshland Test Site
    • Łukasz Zwara
    • Lech Bałachowski
    2022 Full text Materials

    This paper presents different CPT methodologies for the prediction of the pile shaft resistance in tension on the example of three reference screw piles of the Jazowa test site in Poland. The shaft capacity was estimated based on the cone resistance, sleeve friction and CPT excess pore water pressure. Three piles with diameter 0.4 m and the length varied from 8 m to 14.6 m were subjected to static load tests in tension. Their results were used to determine the ultimate bearing capacity of the reference piles. The pile shaft resistance was estimated according to the AFNOR standard, Doan & Lehane 2018 centrifuge tests based method (Delft University of Tech-nology approach), the Modified Unicone method, KTRI (Kajima Technical Research Institute) and LCPC (Laboratoire Central des Ponts et Chaussées) method. Then, the ultimate bearing ca-pacity determined in static load tests was compared to the estimated values according to five different methods. The best estimation fitting almost perfectly to static load tests values was obtained with AFNOR method whereas the other predictions significantly underestimated the ultimate bearing capacity.