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Gdańsk University of Technology

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  • Production and Properties of the Porous Layer Obtained by the Electrochemical Method on the Surface of Austenitic Steel
    • Agnieszka Ossowska
    • Jacek Ryl
    • Tomasz Sternicki
    2022 Full text Materials

    : The growing demand for implants has seen increasing interest in the introduction of new technologies and surface modification methods of metal biomaterials. This research aimed to produce and characterize a porous layer grown on austenitic stainless steel 316L, obtained via the anodization process near the micro-arc oxidation, i.e., low voltage micro-arc oxidation (LVMAO). The discussed layer significantly influences the properties of metallic biomedical materials. The surface topography, layer thickness, surface roughness, pore diameter, elemental composition, crystal structure, and surface wettability were assessed for all anodized layers, together with the resultant corrosion resistance. Attention was paid to the influence of the process parameters that affect the specification of the produced layer. The obtained results showed surface development and different sized pores in the modified layers, as well as an increase in corrosion resistance in the Ringer’s solution.

  • Production of fuel briquette from solid waste biomass using natural resin as a binder
    • Abreham Bekele Bayu
    • Surafel Mustefa Beyan
    • Temesgen Amibo
    • Dereje Tadesse Mekonnen
    2022 Full text Environmental Health Engineering and Management Journal

    Abstract Background: This research aimed to evaluate the use of natural resin as a binder for the production of fuel briquette from solid waste biomass. Methods: Proximate analyses were made for fuel briquette prepared from solid waste biomass using natural resin as a binder in comparison with using starch as a binder. Results: The results for density, percent content of moisture, percent content of volatile matter, percent content of ash, percent content of fixed carbon, and the caloric value of solid waste biomass obtained were 158.23 kg/m3, 18.25%, 65.99%, 4.78%, 10.98%, and 18.65 MJ/kg, respectively. Besides natural resin binder-used fuel briquette was characterized for its density, percent content of porosity weight index, percent content of shatter resistance, percent content of moisture content, percent content of volatile matter, percent content of ash content, percent content of fixed carbon content, and caloric values as 751.05 kg/m3, 13%, 40%, 4%, 12%, 1%, 30%, and 27.05 MJ/kg, respectively. In the same way, the starch binder-used fuel briquette was characterized for its density, percent content of porosity, weight index, percent content of shatter resistance, percent content of moisture content, percent content of volatile matter, percent content of ash, percent content of fixed carbon, and caloric values as 760 kg/m3, 10%, 42%, 4%, 11%, 2%, 31%, and 28.09 MJ/kg, respectively. Conclusion: According to the results of the study, it can be concluded that all characterized properties using natural resin as a binder indicate almost comparative properties in comparison with the use of starch as a binder.

  • Products of Photo- and Thermochemical Rearrangement of 19-Membered di-tert-Butyl-Azoxybenzocrown
    • Ewa Wagner-Wysiecka
    • Paulina Szulc
    • Elżbieta Luboch
    • Jarosław Chojnacki
    • Paweł Sowiński
    • Katarzyna Szwarc-Karabyka
    2022 Full text MOLECULES

    The preparation and characterization of products of the photochemical and thermochemical rearrangements of 19-membered azoxybenzocrowns with two, bulky, tert-butyl substituents in benzene rings in the para positions to oligooxyethylene fragments (meta positions to azoxy group, i.e., t-Bu-19-Azo-O have been presented. In photochemical rearrangement, two colored typical products were expected, i.e., 19-membered o-hydroxy-m,m′-di-tert-butyl-azobenzocrown (t-Bu-19-o-OH) and 19-membered p-hydroxy-m,m′-di-tert-butyl-azobenzocrown (t-Bu-19-p-OH). In experiments, two colored atypical macrocyclic derivatives, one 6-membered and one 5-membered ring, bearing an aldehyde group (t-Bu-19-al) or intramolecular ester group (t-Bu-20-ester), were obtained. Photochemical rearrangement led to one more macrocyclic product being isolated and identified: a 17-membered colorless compound, without an azo moiety, t-Bu-17-p-OH. The yield of the individual compounds was significantly influenced by the reaction conditions. Thermochemical rearrangement led to t-Bu-20-ester as the main product. The structures of the four crystalline products of the rearrangement—t-Bu-19-o-OH, t-Bu-19-p-OH, t-Bu-20-ester and t-Bu-17-p-OH—were determined by the X-ray method. Structures in solution of atypical derivatives (t-Bu-19-al and t-Bu-20-ester) and t-Bu-19-p-OH were defined using NMR spectroscopy. For the newly obtained hydroxyazobenzocrowns, the azo–phenol⇄quinone–hydrazone tautomeric equilibrium was investigated using spectroscopic methods. Complexation studies of alkali and alkaline earth metal cations were studied using UV-Vis absorption spectroscopy. 1H NMR spectroscopy was additionally used to study the cation recognition of metal cations. Cation binding studies in acetonitrile have shown high selectivity towards calcium over magnesium for t-Bu-19-o-OH.

  • Profiling of polar ionogenic metabolites in Polish wines by capillary electrophoresis-mass spectrometry
    • Marlien van Mever
    • Magdalena Fabjanowicz
    • Maricruz Mamani-Huanca
    • Ángeles López-Gonzálvez
    • Justyna Płotka-Wasylka
    • Rawi Ramautar
    2022 Full text ELECTROPHORESIS

    The composition of wine is determined by a complex interaction between environmental factors, genetic factors (i.e., grape varieties), and winemaking practices (including technology and storage). Metabolomics using NMR spec-troscopy, GC-MS, and/or LC-MS has shown to be a useful approach for assessing the origin, authenticity, and quality of various wines. Nonetheless, the use of additional analytical techniques with complementary separation mechanisms may aid in the deeper understanding of wine’s metabolic processes. In this study,we demonstrate that CE-MS is a very suitable approach for the efficient profiling of polar ionogenic metabolites in wines. Without using any sample preparation or derivatization, wine was analyzed using a 10 min CE-MS workflow withinterday RSD values for 31 polar and charged metabolites below 3.8% and 23% for migration times and peak areas, respectively. The utility of this workflow for the global profiling of polar ionogenic metabolites in wine was evaluated by analyzing different cool-climate Polish wine samples.

  • PROJEKT I WDROŻENIE ZAAWANSOWANEGO SYSTEMU TELEMETRII DO POMIARÓW ZACHOWANIA BOLIDU FORMULA STUDENT
    • Karol Pergoł
    • Marcin Nadarzyński
    • Patryk Wittbrodt
    2022

    pracy przedstawiono proces projektowania i wytworzenia zaawansowanego systemu telemetrii, który został zaaplikowany w piątej generacji bolidu stworzonego przez zespół PGRacing Team. Zastosowanie tego rozwiązania pozwoliło na optymalizację konstrukcji i ustawienia zawieszenia pojazdu. Zebrane dane pochodzą z sensorów, w których skład wchodzą m. in. GPS, akcelerometr, czujniki temperatury opon, liniowe czujniki skoku zawieszenia, czujniki prędkości obrotowej kół, czujnik obrotu kierownicy, czujniki natężania prądu, tensometry badające odkształcenie wahaczy. Dodatkowo zbierane są wszystkie dane dotyczące pracy układu napędowego, pochodzące ze sterownika silnika. Dane pomiędzy modułami wchodzącymi w skład systemu przesyłane są z wykorzystaniem magistrali CAN. Wykorzystane mikrokontrolery służące do odczytywania i wstępnego przetwarzania sygnałów pochodzą z rodziny STM32. Dane zapisywane są na nośniku SD oraz przesyłane z wykorzystaniem technologii radiowej do zespołu analizującego je na bieżąco.

  • Projekt układu sterowania ciągiem wektorowanym rakiety
    • Piotr Durawa
    • Kacper Gromko
    • Bartosz Puchalski
    2022 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Artykuł opisuje problem syntezy układu sterowania ciągiem wektorowanym rakiety w strategii pionowego startu i pionowego lądowania. Celem badań było symulacyjne określenie możliwości wykorzystania regulatora liniowo-kwadratowego w układzie sterowania orientacją rakiety podczas lotu. W pracy oprócz badań symulacyjnych zweryfikowano również algorytm sterowania z wykorzystaniem autorskiego stanowiska z rakietą prototypową wyposażoną w turbinę o napędzie elektrycznym, która służyła do wytwarzania siły ciągu. Sterowanie kierunkiem strugi powietrza prototypowej rakiety zapewniał system lotek umieszczony w jej dolnej części. Weryfikacja zaprojektowanego systemu sterowania przebiegła pomyślnie zarówno w warunkach symulacyjnych jak i w trakcie prób z wykorzystaniem stanowiska prototypowego.

  • Projekt "Walizka". Galeria 113 – Galeria Wydziału Sztuki UJD, Częstochowa. Koncepcja wystawy - prof. dr hab.Zbigniew Szot.
    • Dominika Krechowicz
    2022

    Projekt "Walizka". Galeria 113 – Galeria Wydziału Sztuki UJD, Częstochowa. Koncepcja wystawy - prof. dr hab.Zbigniew Szot.

  • Projektowanie, synteza oraz badanie aktywności biologicznej nowych inhibitorów sulfatazy steroidowej (STS) na bazie amidosiarczanowych pochodnych triazoli i oksadiazoli
    • Karol Biernacki
    2022 Full text

    Niniejsza dysertacja dotyczy szeregu badań z wykorzystaniem technik modelowania molekularnego oraz metod syntezy nowych inhibitorów STS opartych o rdzenie pierścieni heterocyklicznych 1,2,3-triazolu oraz 1,2,4-oksadiazolu. Aktywność inhibicyjna otrzymanych pochodnych została oznaczona w testach in vitro z wykorzystaniem enzymu wyizolowanym z łożyska ludzkiego oraz znakowanym radioizotopowo siarczanem estronu, a także w teście komórkowych z wykorzystaniem linii nowotworowej MCF-7 stanowiącej źródło STS. Związki z serii pochodnych 1,2,3-triazolu, wykazujące najwyższą aktywność biologiczną, zostały zbadane w testach in vivo w celu oznaczenia aktywności przeciwnowotworowej w mysim modelu raka sutka

  • Promocja zasobów Pomorskiej Biblioteki Cyfrowej na przykładzie XVIII-wiecznego rękopisu
    • Kamila Kokot-Kanikuła
    • Anna Sobolewska
    2022 Full text Z Badań nad Książką i Księgozbiorami Historycznymi

    Celem artykułu jest przedstawienie sposobu udostępniania i promocji zbiorów rękopiśmiennych na przykładzie XVIII-wiecznego rękopisu Christiana Gabriela Fishera dostępnego w Pomorskiej Bibliotece Cyfrowej (dalej: PBC). Rękopis ten stał się inspiracją do podjęcia współpracy Biblioteki Politechniki Gdańskiej oraz Instytutu Kultury Miejskiej w Gdańsku. Dzięki wspólnej inicjatywie rozpoczęto prace nad transkrypcją niemieckiego tekstu pisanego kurrentą oraz zorganizowano szereg wydarzeń mających na celu popularyzację zarówno dziennika podróży jak i ówczesnej formy kaligrafii wśród współczesnych odbiorców. Wykorzystano informacje statystyczne dotyczące liczby wyświetleń rękopiśmiennego zasobu oraz liczby odwiedzin w okresie od uruchomienia platformy PBC do 31 V 2021 r. W celu zobrazowania popularności i celowości organizowanych wydarzeń, sięgnięto po dane gromadzone przez Instytut Kultury Miejskiej monitorujące uczestników biorących udział w spotkaniach. Dane statystyczne zostały uzupełnione analizą piśmiennictwa na temat promocji zbiorów dziedzictwa kulturowego.

  • Proof of Concept of Indoor Location System Using Long RFID Readers and Passive Tags
    • Jerzy Demkowicz
    • Piotr Łoziński
    2022

    The paper proposes a system for persons and objects location with the use of long radio-frequency identifications (RFIDs) readers. In order to investigate all aspects of the proposed location system, several key elements had to be analyzed, including the distance from which the tagged objects and the possibility of using more than one tag within one RFID range at the same time. When designing the system, it is also necessary to take into account all key elements, but in such a way as to maximize the system range and capacity and minimize its costs, while adapting the system exactly to the requirements. The paper investigates such a system, study its capability and gives some recommendations.

  • Properties of chitosan/CuNPs coatings electrophoretically deposited on TiO2 nanotubular oxide layer of Ti13Zr13Nb alloy
    • Michał Bartmański
    • Łukasz Pawłowski
    2022 MATERIALS LETTERS

    Coatings based on chitosan/CuNPs (chit/CuNPs) were obtained by a one-step electrophoretic deposition (EPD) on nanotubular oxide layer of Ti13Zr13Nb alloy. The deposition was carried out for 1 min applying voltages of 10 and 20 V with and without the addition of dispersing agent (Polysorbate 20) to the suspension. The coatings obtained for the lower voltage were more uniform than for the higher voltage. By adding a dispersing agent, the agglomeration of copper nanoparticles was reduced, resulting in better adhesion of the coating to the metallic substrate, good corrosion resistance and improved wettability

  • Properties of New Composite Materials Based on Hydroxyapatite Ceramic and Cross-Linked Gelatin for Biomedical Applications
    • Michał Bartmański
    • Magda Rościszewska
    • Marcin Wekwejt
    • Anna Ronowska
    • Małgorzata Nadolska-Dawidowska
    • Aleksandra Mielewczyk-Gryń
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    The main aim of the research was to develop a new biocompatible and injectable composite with the potential for application as a bone-to-implant bonding material or as a bone substitute. A composite based on hydroxyapatite, gelatin, and two various types of commercially available transglutaminase (TgBDF/TgSNF), as a cross-linking agent, was proposed. To evaluate the impacts of composite content and processing parameters on various properties of the material, the following research was performed: the morphology was examined by SEM microscopy, the chemical structure by FTIR spectroscopy, the degradation behavior was examined in simulated body fluid, the injectability test was performed using an automatic syringe pump, the mechanical properties using a nanoindentation technique, the surface wettability was examined by an optical tensiometer, and the cell viability was assayed by MTT and LDH. In all cases, a composite paste was successfully obtained. Injectability varied between 8 and 15 min. The type of transglutaminase did not significantly affect the surface topography or chemical composition. All samples demonstrated proper nanomechanical properties with Young’s modulus and the hardness close to the values of natural bone. BDF demonstrated better hydrophilic properties and structural stability over 7 days in comparison with SNF. In all cases, the transglutaminase did not lead to cell necrosis, but cellular proliferation was significantly inhibited, especially for the BDF agent.

  • Properties of Old Concrete Built in the Former Leipziger Palace
    • Andrzej Ambroziak
    • Elżbieta Haustein
    2022 Full text Materials

    This research aims to determine the mechanical, chemical, and physical properties of old concrete used in the former Leipziger Palace in Wrocław, Poland. The cylindrical specimens were taken from the basement concrete walls using a concrete core borehole diamond drill machine. The determination of the durability and strength of old concrete was based on specified chosen properties of the old concrete obtained through the following set of tests: measurements of dry density, tests of water absorption, specification of concrete compressive strength and frost resistance, determination of the modulus of elasticity, measurement of the pH value, determination of water-soluble chloride salts and sulphate ions, and X-ray diffraction analyses. Large dispersions of the compressive strength (10.4 MPa to 34.2 MPa), density (2049 kg/m3 to 2205 kg/m3), water absorption (4.72% to 6.55%), and stabilized secant modulus of elasticity (15.25 Gpa to 19.96 GPa) were observed. The paper is intended to provide scientists, civil engineers, and designers with guidelines for examining and assessing the long-term durability of old concrete, and also extending knowledge in the field of archaeological restoration and the protection of old concrete structures.

  • Properties of Oxygen Vacancy and Hydrogen Interstitial Defects in Strontium Titanate: DFT + Ud,p Calculations
    • Szymon Winczewski
    • Jacek Dziedzic
    • Tadeusz Miruszewski
    • Jarosław Rybicki
    • Maria Gazda
    2022 Full text Journal of Physical Chemistry C

    This work presents extensive theoretical studies focused on the mixed ion-electron transport in cubic strontium titanate (STO). A new approach to the description of this difficult system was developed within the framework of linear-scaling Kohn–Sham density functional theory, as realized in the ONETEP program. The description we present is free of any empirical parameters and relies on the Hubbard U and Hund’s J corrections applied to both Ti and O atoms. The proposed methodology was validated by considering perfect STO. Its calculated properties were found to be in close agreement with experiments and calculations at higher levels of theory. The validated approach was subsequently employed to study the oxygen vacancy (VO) and the hydrogen interstitial (IH), using very large supercells (625 ± 1 atoms). The relaxed configurations of defects were obtained through fastidious energy minimization and later analyzed from a number of perspectives. The calculated defect formation energies and charge transition levels (CTLs) were found to be in close agreement with the experiment. With the exception of the charge-neutral VO, all considered defects were found to introduce shallow states, located down to 0.2 eV below the conduction band. Our calculations revealed a large 1 eV difference in the thermodynamic and optical CTLs of the neutral VO, explaining the inconsistencies observed─till now─between conduction and spectroscopic measurements. The influence of defects on the bonding characteristics and the crystalline structure of STO was quantified, revealing that both VO and IH defects lead to a significant polarization and strong tilting of the TiO6 octahedra.

  • Propozycja procedury obliczania i projektowania fundamentów palowych
    • Adam Krasiński
    2022

    W artykule przedstawia propozycję podejścia do obliczania fundamentów palowych, w którym nośność pala rozpatrywana jest nie jako wartość liczbowa Rd, wyrażona w kN, lecz jako charakterystyka obciążenie-osiadanie Q-s, wyrażona w postaci funkcji lub wykresu. Dla uproszczenia, nieliniową charakterystykę Q-s pala zastąpiono wykresem biliniowym (łamanym). Równolegle zaproponowano nowe podejście do analizowania i interpretowania wyników obliczeń statycznych fundamentów palowych oraz do oceny wyników próbnych obciążeń pali. Na trzech przykładach obliczeniowych wykazano, że proponowane podejście obliczeniowe jest zasadne i może przynosić korzyści.

  • Protocolo de Preparación y Evaluación de Pilas de Combustible de Óxido Sólido
    • Araceli Fuerte
    • Rita X. Valenzuela
    • Paloma Ferreira-Aparicio
    • Beata Bochentyn
    2022

    Este protocolo describe la metodología para la preparación de celdas de óxido sólido y su evaluación como pila de combustible (SOFC). Es fruto del estudio realizado en el marco de los proyectos FCTESTNET [1] y SOFCNET [2] del V Programa Marco, en el Comité IEC/TC105 [3] e investigaciones llevadas a cabo en el laboratorio. Las pilas de combustible son dispositivos capaces de transformar la energía química de un combustible en energía eléctrica, con alta eficiencia y baja o nula emisión de contaminantes a la atmósfera. En el marco energético y medioambiental actual resulta imprescindible el desarrollo de sistemas de conversión de energía más eficientes, viables económicamente y no contaminantes. La definición de protocolos estandarizados de preparación y evaluación de este tipo de dispositivos ayudará al rápido desarrollo y comercialización de los mismos y con ello a la necesaria transición energética. De entre las posibles configuraciones, en el presente trabajo se define el protocolo para la preparación de celdas de óxido sólido soportadas sobre el electrolito. Además, se detalla el protocolo para la evaluación de pilas de combustible SOFC alimentadas con diferentes combustibles y bajo diferentes condiciones de operación, así como para el análisis post-operacional a fin de evaluar las posibles causas de degradación de estos dispositivos. Los resultados obtenidos con la aplicación de estos protocolos han demostrado que son aptos para la preparación y evaluación de las prestaciones de las pilas de combustible de óxido sólido SOFC, permitiendo la evaluación de prestaciones de nuevos materiales y de diferentes celdas, así como identificar mecanismos de degradación en función de los materiales utilizados o de las condiciones de operación. De este modo, se pueden buscar soluciones que subsanen estas limitaciones y con ello ayudar al posterior escalado y comercialización de estos dispositivos.

  • Proton-Electron Hole Interactions in Sr(Ti,Fe)O3−δ Mixed-Conducting Perovskites
    • Tadeusz Miruszewski
    • Wojciech Skubida
    • Piotr Winiarz
    • Kacper Dzierzgowski
    • Aleksandra Mielewczyk-Gryń
    • Sebastian Wachowski
    • Maria Gazda
    2022 JOURNAL OF THE ELECTROCHEMICAL SOCIETY

    Oxides in which total electrical conductivity is determined by the partial conductivities of three types of charge carriers i.e. holes/ electrons, oxygen ions, and protons are key components of well-functioning proton ceramic fuel cells. Apart from electrochemical properties also easily modified microstructure is an important feature of the electrodes. In the paper, a group of SrTi1−xFexO3−δ (STF, x = 0.2–0.8) perovskites prepared by solid-state synthesis was studied. The microstructure of ceramics was studied using SEM, and the results showed a significant influence of Fe amount on the grain size and material’s porosity. The electrical transport results show a different conductivity in a dry and humidified atmosphere. The hydration kinetics related to the water incorporation are presented with the transition from single-fold to two-fold behaviour, related to the proton-electron hole interaction observed in measurements. The obtained results strictly show a triple-conductivity of SrTi0.8Fe0.2O3−δ system at a lower temperature range, where the protonic defects are thermodynamically stable.

  • Prototype and design of six axis robotic manipulator
    • Mateusz Pająk
    • Marcin Racław
    • Robert Piotrowski
    2022 Full text Journal of Automation, Mobile Robotics and Intelligent Systems - JAMRIS

    The paper presents a design of six axis manipulator. The design consists of specially designed solutions for housing, planetary gearboxes and electronics. The manipulator is controlled by a supervisory control system. The use of a series of measuring elements allows to track the current position of each axis and use this to create a cascade control loop with velocity and acceleration feed-forward. The implemented control algorithm together with the microcontroller software allows to tune parameters of the controllers for both control loops: inner, related to the speed of the robot and outer, related to it’s position.

  • Provenance studies on Late Neolithic amber ornaments from North-East Poland
    • Dariusz Manasterski
    • Ewa Wagner-Wysiecka
    • Katarzyna Kwiatkowska
    • Aleksandra Cetwińska
    2022 Full text Journal of Archaeological Science-Reports

    The area of North-East Poland was in prehistory, and still is today, an area with easy access to amber as a raw material, as is evidenced in part by numerous Late Neolithic (3rd millennium) amber workshops located in the Gulf of Gdańsk and Żuławy Wiślane (Vistula Fens). Given this fact, it is surprising that only a few finished amber products have been recovered from this area. Among them are unique ornaments from the Late Neolithic sites Ząbie 10, Supraśl 3, and Supraśl 6. The preliminary analysis showed that these amber artifacts differ from the products manufactured by local groups located in the territory of modern Poland. The selected artifacts were subjected to in-depth stylistic and technological analysis to identify their provenance, taking also into consideration the type of raw material used in their production by means of FTIR analysis. Stylistic analysis showed that several specimens have analogies amongst the amber beads known from the Bell Beaker phenomenon. However, most of the beads under study are unique, and there are no analogies among any Neolithic ornaments in Europe. In addition, it was found that the specimens from Ząbie 10, Supraśl 3, and Supraśl 6 had perforations drilled with a metal tool, not a flint drill bit, which was previously unheard of in this part of Europe. The FTIR analysis revealed the use of local amber, including its different varieties i.e., succinite, gedano-succinite and gedanite. It also revealed its varying state of preservation. This may be useful for exploring the environmental context in which these artifacts were deposited.

  • Przedsiębiorczość technologiczna – wysokie technologie, badania i rozwój.
    • Nelly Daszkiewicz
    2022

    Dotychczas nie powstała jedna definicja przedsiębiorczości technologicznej (PT) z uwagi na złożoność zjawiska. Najogólniej, PT łączy zagadnienia związane z przedsiębiorczością oraz zarządzaniem technologią i innowacjami, jak również nauki społeczne z naukami technicznymi. Rozdział kompleksowo wyjaśnia pojęcie PT oraz przedsywia analizę historyczną pojęcia

  • Przegląd metod wytwarzania energii elektrycznej z wodoru i ocena potencjału ich zastosowania w krajowym systemie elektroenergetycznym
    • Jakub Łukasik
    • Marcin Jewartowski
    2022 Rynek Energii

    W artykule dokonano przeglądu dostępnych metod wytwarzania energii elektrycznej z udziałem technologii wodorowych i podjęto próbę oceny potencjału ich zastosowania w polskim systemie elektroenergetycznym. Szczególną uwagę poświęcono ogniwom paliwowym, omawiając dostępne na rynku typy ogniw oraz ich podstawowe parametry techniczne. W zakresie technologii wodorowych, rozważono możliwość samodzielnej pracy ogniw paliwowych, turbin gazowych i silników tłokowych w strukturze rozproszonej, jak też zasadność współpracy wybranych układów w formie systemów hybrydowych. Przytoczono przy tym zalety i wady omawianych rozwiązań. Zwrócono uwagę na wysoki potencjał niektórych układów do pracy w poligeneracji. W oparciu o studia literaturowe, oszacowano jednostkowe koszty inwestycyjne i operacyjne omawianych technologii w perspektywie roku 2050. Mają one istotne znaczenie w aspekcie aktualnych proekologicznych strategii energetycznych, które są bodźcem do transformacji krajowego systemu elektroenergetycznego.

  • Przekształtnik SiC DC-DC z transformatorem macierzowym do pokładowych ładowarek baterii akumulatorów taboru 3kV DC
    • Marek Adamowicz
    • Jędrzej Pietryka
    • Zbigniew Krzemiński
    2022

    Baterie akumulatorów pojazdów trakcyjnych zapewniają zasilanie krytycznych systemów, takich jak sterowanie i oświetlenie. Zgodnie z wymaganiami przemysłu kolejowego, pokładowa ładowarka baterii akumulatorów powinna być urządzeniem kompaktowym, wysokosprawnym, a jednocześnie wysoce niezawodnym. W referacie, do pokładowego ładowania akumulatorów pociągu zaproponowano kompaktowy przekształtnik SiC DC-DC z transformatorem macierzowym 16:1, zintegrowany z główną przetwornicą pomocniczą pociągu o konstrukcji dachowej. Cały system przetwornicy głównej ze zintegrowaną ładowarką zapewnia przetwarzanie energii z poziomu 3kV DC do poziomu 24V przy zachowaniu wysokiej sprawności.

  • Przęsło łukowe kolejowego obiektu mostowego. Wpływ schematu statycznego i rozwiązań konstrukcyjnych na właściwości dynamiczne
    • Przemysław Kalitowski
    2022 Full text

    W pracy przedstawiono kompleksową analizę optymalizacyjną kolejowego wiaduktu łukowego. Szczególną uwagę zwrócono na zachowanie dynamiczne konstrukcji. Odpowiedź dynamiczna przęsła pod obciążeniem taboru Kolei Dużych Prędkości (KDP) jest jednym z kluczowych elementów podlegających ocenie przy projektowaniu obiektów wzdłuż KDP. Drgania przęsła ograniczane są ze względu na trwałość i bezpieczeństwo konstrukcji oraz komfort pasażerów. Sformułowano procedurę, w której połączono analizę numeryczną Metodą Elementów Skończonych oraz wielokryterialną optymalizację rojem cząstek (PSO) do poszukiwania zestawu najlepszych rozwiązań ze względu na ilość zużytego materiału i odpowiedź dynamiczną konstrukcji. Procedurę zaprezentowano na przykładzie istniejącego łukowego wiaduktu kolejowego WK-2 o rozpiętości 70 m w ciągu Pomorskiej Kolei Metropolitalnej. Parametry dynamiczne obiektu zidentyfikowano za pomocą procedury NExT-ERA Operacyjnej Analizy Modalnej. Zbudowany model MES skalibrowano wykorzystując wyniki badań i metodę optymalizacji PSO. Przeanalizowano dziewięć wariantów optymalizacji różniących się układem wieszaków oraz maksymalną prędkością przejazdu. Uwzględniono wieszaki pionowe, ukośne i Network oraz prędkości 160, 200 i 300 km/h. Zestawione wyniki pozwoliły na ocenę przydatności i opłacalności poszczególnych wariantów konstrukcji w zastosowaniach w ciągu KDP. Podjęto również próbę określenia zależności pomiędzy wielkością głównych elementów konstrukcyjnych, a odpowiedzią dynamiczną wiaduktu.

  • Przyczyna uszkodzeń uzwojeń silników 6 kV 500 kW, zainstalowanych w pompowni ujęcia wody
    • Dariusz Karkosiński
    • Dawid Łuszcz
    • Marek Olesz
    2022 Automatyka Elektryka Zakłócenia

    W artykule przedstawiono analizę przyczyn uszkodzeń silników średniej mocy i SN, służących do napędu pomp ujęcia wody dla miasta. Użytkownik pompowni w celu regulacji wydatku pomp zastosował przemiennik częstotliwości niskiego napięcia, których został zasilony przez transformator 6/0,4 kV. Napięcie za przemiennikiem było podnoszone poprzez transformator 0,4/6 kV i zasilało poprzez linie kablowe silniki pomp. W ciągu 2. lat od wdrożenia regulacji częstotliwościowej, w 3. silnikach wystąpiły uszkodzenie izolacji. Powodem tego zjawiska były chwilowe napięcie aż 2. krotnie większe od wartości dopuszczalnej.

  • Przyszłość fotowoltaiki – czy zaleje nas fala odpadów?
    • Ewa Klugmann-Radziemska
    2022 Full text Pismo PG

    Rozwój fotowoltaiki na świecie utrzymuje się przez ostatnie 40 lat na bardzo wysokim, 40-procentowym wzroście rok-do-roku. Również w Polsce obserwujemy od kilku lat rosnące zainteresowanie, zwłaszcza instalacjami prosumenckimi, głównie dzięki licznym programom wspierającym inwestycje. Znaczny udział systemów fotowoltaicznych w generowaniu energii elektrycznej na całym świecie przynosi niewątpliwe korzyści dla środowiska naturalnego, ponieważ systemy te nie są źródłem hałasu ani emisji szkodliwych substancji czy gazów cieplarnianych. Energia elektryczna wytwarzana z paliw kopalnych odpowiada za emisję gazów cieplarnianych na poziomie od 400 g do 1000 g CO2eq./kWh, podczas gdy ich emisja z krzemowych modułów fotowoltaicznych jest znikoma. Zakłada się, że moduły fotowoltaiczne powinny pełnić swoją funkcję 25 lat. Jednak, aby pozostały one bez negatywnego wpływu na środowisko, konieczne jest wprowadzenie długofalowej strategii obejmującej kompletny cykl życia wszystkich elementów systemu: od fazy produkcji, poprzez montaż i eksploatację aż do zagospodarowania odpadów. Recykling zużytych lub uszkodzonych modułów jest istotnym elementem tej strategii.

  • Psychological capital and happiness at work: The mediating role of employee thriving in multinational corporations
    • Beata Basińska
    • Małgorzata Rozkwitalska
    2022 Full text CURRENT PSYCHOLOGY

    Working in multicultural work environments of multinational corporations (MNCs) creates challenges whose expected impact on happiness is equivocal. In the following paper, we examine the relationship between psychological capital and happiness at work in the specific MNCs’ context. We assume that thriving (eudemonic well-being) at work fosters individuals’ development and enhances their happiness composed of both the affective (positivity) and cognitive (satisfaction with intercultural interactions) components. A sample of 137 individuals from subsidiaries of various MNCs and involved in intercultural interactions was included in the cross-sectional study. In order to test the mediating effect of vitality and learning, i.e., both components of thriving, on the psychological capital and happiness at work, as well as a moderating effect of psychological capital between thriving and happiness in a multicultural work setting, a bootstrapping analysis was conducted. Prior international experience and job tenure were control variables. The results show that psychological capital as resource caravans is positively associated with learning and further is related to more satisfaction with intercultural interactions. Moreover, psychological capital is associated with more vitality at work and further favourably relates to positivity. We also demonstrate that psychological capital does not moderate the relationship between thriving and happiness at work. The research broadens the understanding of positive aspects of well-being in the unique environment of MNCs. Our study suggests that managers should stimulate learning and vitality by managerial practices concerning improvement of employee psychological capital since then they may strengthen happiness at work.

  • pt. „PRZYSTANEK OD ZGIEŁKU MIASTA # Gdańsk-Letnica”
    • Agnieszka Kurkowska
    2022

    plakat promujący wystawę pt. „PRZYSTANEK OD ZGIEŁKU MIASTA # Gdańsk-Letnica” w mediach społecznościowych oraz fizycznie w siedzibie GAK Gama w Gdańsku-Letnicy

  • Public Finance in Poland in a COVID Fog: A Look Through the Lens of Fiscal Transparency and Accountability
    • Maria Jastrzębska
    2022 Full text Studies in Logic, Grammar and Rhetoric

    Abstract. Goal– The aim of the article is to identify dysfunctional phenomena (implementation of specific mechanisms/solutions and actions taken), generating increased opacity and limit the responsibility/accountability of public f inance in Poland, exacerbated by the COVID-19 crisis. Methods– descriptive analysis, comparative analysis and financial analysis methods were used. Results– fiscal transparency and accountability in Poland is limited by: the marginalisation of the role of the state budget, the loosening of the stabilising expenditure rule, the creation of financial mechanisms based on special funds fed by repayable financing sources for the implementation of state tasks, inter alia, in the fight against the effects of the COVID-19 crisis, the use of national and EU methodologies for calculating the deficit and debt of the public sector in order to conceal part of them, the lack of a consolidated financial statement of the public finance sector.

  • Pure cross-anisotropy for geotechnical elastic potentials
    • Andrzej Niemunis
    • Katarzyna Staszewska
    2022 Full text Acta Geotechnica

    The pure cross-anisotropy is understood as a special scaling of strain (or stress). The scaled tensor is used as an argument in the elastic stiffness (or compliance). Such anisotropy can be overlaid on the top of any elastic stiffness, in particular on one obtained from an elastic potential with its own stress-induced anisotropy. This superposition does not violate the Second Law. The method can be also applied to other functions like plastic potentials or yield surfaces, wherever some cross-anisotropy is desired. The pure cross-anisotropy is described by the sedimentation vector and at most two constants. Scaling with more than two purely anisotropic constants is shown impossible. The formulation was compared with experiments and alternative approaches. Static and dynamic calibration of the pure anisotropy is also discussed. Graphic representation of stiffness with the popular response envelopes requires some enhancement for anisotropy. Several examples are presented. All derivations and examples were accomplished using the algebra program Mathematica.

  • Pursuing Analytically the Influence of Hearing Aid Use on Auditory Perception in Various Acoustic Situations
    • Piotr Szymański
    • Tomasz Poremski
    • Bożena Kostek
    2022 Full text Vibrations in Physical Systems

    The paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken into consideration. A web-based application is developed, allowing answering the survey questions from any computer with Internet access. The results of the benefit obtained from the use of hearing aids in various acoustic environments, taking into account the time of their use, are presented and compared to the earlier outcomes. The research results show that in the first period of use of hearing aids, speech perception improves, especially in noisy environments. The perception of unpleasant sounds also increases, which may lead to deterioration of hearing aid acceptance by their users.

  • Pursuing Listeners’ Perceptual Response in Audio-Visual Interactions - Headphones vs Loudspeakers: A Case Study
    • Bartłomiej Mróz
    • Bożena Kostek
    2022 Full text Archives of Acoustics

    This study investigates listeners’ perceptual responses in audio-visual interactions concerning binaural spatial audio. Audio stimuli are coupled with or without visual cues to the listeners. The subjective test participants are tasked to indicate the direction of the incoming sound while listening to the audio stimulus via loudspeakers or headphones with the head-related transfer function (HRTF) plugin. First, the methodology assumptions and the experimental setup are described to the participants. Then, the results are presented and analysed using statistical methods. The results indicate that the headphone trials showed much higher perceptual ambiguity for the listeners than when the sound is delivered via loudspeakers. The influence of the visual modality dominates the audio-visual evaluation when loudspeaker playback is employed. Moreover, when the visual stimulus is present, the headphone playback pattern of behavior is not always in response to the loudspeaker playback.

  • Pursuing the Deep-Learning-Based Classification of Exposed and Imagined Colors from EEG
    • Alejandro A. Torres-García
    • Jesus Garcia Salinas
    • Luis Villaseñor-Pineda
    2022 LECTURE NOTES IN COMPUTER SCIENCE

    EEG-based brain-computer interfaces are systems aiming to integrate disabled people into their environments. Nevertheless, their control could not be intuitive or depend on an active external stimulator to generate the responses for interacting with it. Targeting the second issue, a novel paradigm is explored in this paper, which depends on a passive stimulus by measuring the EEG responses of a subject to the primary colors (red, green, and blue). Particularly, we assess if a compact and feature-extraction-independent deep learning method (EEGNet) can effectively learn from these EEG responses. Our outcomes outperformed previous works focused on a dataset composed of EEG signals belonging to 7 subjects while seeing and imagining three primary colors. The method reaches an accuracy of 45% for exposed colors, 43% for imagined colors, and 35% for the six classes. Last, the experiments suggest that EEGNet learned to discover patterns in the EEG signals recorded for imagined and exposed colors, and for the six classes, too.

  • Pyrolysis Combined with the Dry Reforming of Waste Plastics as a Potential Method for Resource Recovery—A Review of Process Parameters and Catalysts
    • Ewelina Pawelczyk
    • Izabela Wysocka
    • Jacek Gębicki
    2022 Full text Catalysts

    : Emissions of greenhouse gases and growing amounts of waste plastic are serious environmental threats that need urgent attention. The current methods dedicated to waste plastic recycling are still insufficient and it is necessary to search for new technologies for waste plastic management. The pyrolysis-catalytic dry reforming (PCDR) of waste plastic is a promising pro-environmental way employed for the reduction of both CO2 and waste plastic remains. PCDR allows for resource recovery, converting carbon dioxide and waste plastics into synthetic gas. The development and optimization of this technology for the high yield of high-quality synthesis gas generation requires the full understanding of the complex influence of the process parameters on efficiency and selectivity. In this regard, this review summarizes the recent findings in the field. The effect of process parameters as well as the type of catalyst and feedstock are reviewed and discussed.

  • Pyrolysis of RDF and Catalytic Decomposition of the Produced Tar in a Char Bed Secondary Reactor as an Efficient Source of Syngas
    • Bogusław Kusz
    • Dariusz Kardaś
    • Łukasz Heda
    • Bartosz Trawiński
    2022 Full text Processes

    One of the technical limitations of refuse-derived fuel (RDF) pyrolysis is the high content of tar in its gas products. In order to resolve this problem, a two-stage RDF pyrolysis with a catalyst based on char from RDF pyrolysis is proposed. This paper presents the results of municipal waste pyrolysis beginning in an oven heated to 480 °C and ending with catalytic tar cracking carried out in the temperature range from 800 to 1000 °C. Thermal and catalytic pyrolysis with a char catalyst containing a minimum of 6% Fe resulted in increases in the CO and H2 contents in gas products and decreases in CO2 and CH4. At 1000 °C, the mass ratio of gaseous products to liquids was greater than 6. The residence time of the gases in the catalytic zone was about 3–5 s. The reactor was a good source of hydrogen and carbon monoxide.

  • Pyrrole bearing diazocrowns: Selective chromoionophores for lead(II) optical sensing
    • Błażej Galiński
    • Ewa Wagner-Wysiecka
    2022 Full text SENSORS AND ACTUATORS B-CHEMICAL

    Diazocrowns of 18-, 21- and 23-membered rings with pyrrole residue as a part of macrocycle were for the first time used as chromoionophores in lead(II) selective optodes. Sensing properties of optodes depend on the type of macrocycle, namely its size and the type of linker: oligoether or hydrocarbon chain. The best results were obtained for optode bearing 18-membered crown with oligoether linker showing linear response range of 8.05 × 10−8–2.24 × 10−5 M lead(II) and detection limit of 1.15 × 10−8 M. Membrane, based on cellulose triacetate, is lead(II) selective giving color change from red to different shades of blue (pH 5.5). Results obtained for model and real samples of lead(II) showed that easily accessible and regenerable sensor material can be used for spectrophotometric and colorimetric (Digital Color Analysis) detection and determination of lead(II).

  • QoS Extensions for Flow-Awareness Networks
    • Sylwester Kaczmarek
    • Maciej Wolff
    2022 Full text International Journal of Electronics and Telecommunications

    The paper contains a description and research results of the proposal for distributed QoS extensions for Flow-Based Networking. These QoS extensions let the network accept or reject flows based on current network load and QoS promises for each of the flows. Proposed solution consists of two distributed components, each of them performing in every node, measurement system and access control. The solution could be applied in any network architecture that is able to distinguish flows and routers in this architecture contains flow state table. Proposed approach was verified by simulation, in FSA architecture. Verification was done for six different network structures servicing two traffic classes (MRS, ARS). The results of the simulation tests have confirmed that the average time delay and packet loss ratio in the network with proposed extensions are below thresholds and meet the requirements recommended by ITU-T.

  • QoS Resource Reservation Mechanisms for Switched Optical Networks
    • Sylwester Kaczmarek
    • Magdalena Młynarczuk
    • Arkadiusz Dumin
    2022

    The paper regards the problem of resource reservation mechanisms for Quality of Service support in switched optical networks. The authors propose modifications and extensions for resources reservation strategy algorithms with resources pools, link capacity threshold and adaptive advance reservation approach. They examine proposed solutions in Automatically Switched Optical Network with Generalized Multi-Protocol Label Switching named as ASON/GMPLS network. The analysis is performed by simulation the Polish network structure with the use of OMNeT++ discrete-event simulator.

  • QRS Morphology-Based EDR Signal—Factors Determining its Properties
    • Piotr Przystup
    • Artur Poliński
    • Jerzy Wtorek
    2022 Full text IEEE Access

    Respiration-induced signals contain a clinically significant information. It could be obtained utilizing both direct and indirect methods. ECG-Derived Respiration (EDR) method is the latter one. However, in this case, two approaches could be distinguished. First one is based on determining changes in the morphology of QRS complexes while the second one is based on the Respiratory Sinus Arrhythmia (RSA) mechanism. The former approach is discussed in the paper. The basic properties of QRS morphology-based EDR signal were evaluated by means of simulations performed using a developed FEM model and appropriate experiments. In effect, basing on changes of the leads’ voltages induced by a heart translation or rotation, or by both mechanisms undergoing simultaneously, the sensitivity-like surfaces and the synthetic EDR signals were obtained. A very good agreement of the experimental and simulation results was achieved. The QRS morphology-based signal’s properties strongly depend on geometrical relation of the used lead to dominating direction of the heart translation, its rotation, and on personal relation between these two mechanisms. The conclusions presented should be taken into account especially when developing or using QRS morphology-based approach in respiratory monitoring systems.

  • Qualia: About Personal Emotions Representing Temporal Form of Impressions - Implementation Hypothesis and Application Example
    • Zdzisław Kowalczuk
    • Michał Czubenko
    • Marlena Gruba
    2022

    The aim of this article is to present the new extension of the xEmotion system as a computerized emotional system, part of an Intelligent System of Decision making (ISD) that combines the theories of affective psychology and philosophy of mind. At the same time, the authors try to find a practical impulse or evidence for a general reflection on the treatment of emotions as transitional states, which at some point may lead to the emergence of new emotional qualities ascribed to phenomena (objects or events) perceived by the agent. Since there is a dispute in the literature about the meaning and usefulness of `private' emotions, the article attempts to present in a transparent and technical manner the problem of hypothetical qualia against the background of selected theories of emotions, taking into account the cultural aspect or division. By treating qualia as an expression of individual emotional diversity and learning capacity, qualia can be assigned a quite technical role in modeling the human mind and in implementing autonomous robots and agents.

  • Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
    • Monika Zamłyńska
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    2022

    Application of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency division multiplexing (OFDM) is widely utilized both in wired and wireless transmission. In this paper we investigate the quality of service (QoS) parameters of a simulated data transmission system, dedicated particularly to audio and video content distribution with orthogonal frequency division multiplexing. The audio research part involves a group of four language sets, namely: American English, British English, German, and Polish, processed using the Ogg Vorbis format. Whereas, in the video part we investigate a set of MPEG-4 video sequences coded at standard resolution of 480 × 270 pixels. Tests were performed under varying network and bandwidth conditions, including signal-to-noise ratio (SNR) and bit error rate (BER). Results of this study may aid parties interested in designing additional backup or supplementary services for portable devices and user terminals, including reliable means of contact, surveillance and monitoring for the Industry 4.0 and Internet of things (IoT) concept.

  • Quality assessment of low voltage surge arresters
    • Leszek Litzbarski
    • Marek Olesz
    • Stanisław Wojtas
    • Michał Winiarski
    • Tomasz Klimczuk
    • Hubert Glowinski
    • Bartłomiej Andrzejewski
    2022 Full text IEEE Access

    Users expect reliable operation of the surge arrester during overvoltages, which may originate from a switching process or a lightning discharge. The necessary conditions to guarantee these expectations are: appropriate construction of the surge arrester, its production being maintained in accordance with technical standards, and a positive results of the type test (as well routine and acceptance tests). The recipient, especially when purchasing large quantities of the product, can check the final quality of the product through selective testing of samples from the market in order to find the best supplier. This manuscript specifies the basic parameters of low-voltage (LV) surge arresters of four manufacturers. Basic electrical parameters, i.e. leakage current and varistor voltage (U1mA) before and after the nominal discharge current (In) of 8 µs/20 µs, were determined for 10 randomly selected surge arresters of each manufacturer. Moreover one sample of each varistor batches was aged by fifty 8 µs/20 µs current impulses with In. The obtained results of structural analysis indicate that the crystal structure of the varistor materials changes after ageing process, affecting its electrical properties. The proposed research methodology can be employed as a basis for forecasting the stability of the arrester parameters under operating conditions.

  • Quality Control of Bacterial Extracellular Vesicles with Total Protein Content Assay, Nanoparticles Tracking Analysis, and Capillary Electrophoresis
    • Aleksandra Steć
    • Joanna Jońca
    • Krzysztof Waleron
    • Małgorzata Waleron
    • Agata Płoska
    • Leszek Kalinowski
    • Bartosz Wielgomas
    • Szymon Dziomba
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Extracellular vesicles (EVs) were isolated from Pectobacterium zantedeschiae culturing media using direct ultracentrifugation (UC), iodixanol cushion ultracentrifugation (ICUC), and iodixanol density gradient ultracentrifugation (IDGUC) techniques. The isolates were characterized with total protein content assay (bicinchoninic acid assay, BCA), nanoparticles tracking analysis (NTA), and capillary electrophoresis (CE). A satisfactory correlation (R2 > 0.94) between quantitative results obtained with BCA, NTA and CE was achieved only for isolates obtained with the IDGUC. The correlation between protein content and CE was proved to be related to the isolates’ purity. The NTA was found unable to provide reliable information on EVs quantity in samples isolated with UC and ICUC, due to the co-isolated particulate impurities. Moreover, the work reports polysaccharides, used as culturing media components, as a potential source of bias of quantitation with total protein content assay and NTA. The study demonstrates the advantageous selectivity of CE in quality control of EVs and its ability to differentiate subpopulations of EVs of Pectobacterium.

  • Quality of Cryptocurrency Mining on Previous Generation NVIDIA GTX GPUs
    • Jerzy Demkowicz
    • Maciej Rutkowski
    • Przemysław Falkowski-Gilski
    2022

    Currently, there is a lot of previous generation NVIDIA GTX graphical processing units (GPUs) available on the market, which were ousted from by next-gen RTX units. Due to this fact, numerous fully-operational devices remain underused, which are available at an affordable price. First, this paper presents an analysis of the cryptocurrency market. Next, in this context, the results of research on the performance of NVIDIA graphics cards with dedicated software as a cryptocurrency mining platform. The research included three hardware platforms: GTX 480 x1, GTX 480 x2 and GTX 760 x1, tested under four cryptocurrencies, namely: Bitcoin, Litecoin, Monero and Ethereum. The custom-build test bench included power consumption as well as the efficiency of mining various digital currencies. Obtained results can aid any investigator interested in designing his own stand as well as configuring the environment.

  • Quantification of Compatibility Between Polymeric Excipients and Atenolol Using Principal Component Analysis and Hierarchical Cluster Analysis
    • Barbara Rojek
    • Maria Gazda
    • Marek Wesolowski
    2022 Full text AAPS PharmSciTech

    An important challenge to overcome in the solid dosage forms technology is the selection of the most biopharmaceutically efficient polymeric excipients. The excipients can be selected, among others, by compatibility studies since incompatibilities between ingredients of the drug formulations adversely affect their bioavailability, stability, efficacy, and safety. Therefore, new, fast, and reliable methods for detecting incompatibility are constantly being sought. Hence, the purpose of this work was to assess the usefulness of a heating, cooling, and reheating differential scanning calorimetry (DSC) program for detecting potential incompatibilities between atenolol, an active pharmaceutical ingredient (API), and polymeric excipients. Hot-stage microscopy (HSM), Fourier transform infrared (FTIR) spectroscopy, and powder X-ray diffraction (PXRD) were used as supporting techniques. Additionally, principal component analysis (PCA) and hierarchical cluster analysis (HCA) served as tools to support the interpretation of the data acquired from the DSC curves and FTIR spectra. As the alterations in the shape of the DSC peak of atenolol which are indicative of incompatibility are visible only on the cooling and reheating curves of the mixtures, the DSC heating–cooling–reheating program was found to be very useful for identifying potential incompatibilities in the binary mixtures of atenolol and polymeric excipients. The melting and recrystallization of atenolol alone and in its mixtures were also confirmed by HSM, while FTIR displayed changes in the spectra of mixtures due to incompatibility. These studies revealed that atenolol is incompatible with hydroxyethylcellulose, hypromellose, and methylcellulose. PXRD measurements at room temperature revealed that the crystallinity of atenolol did not change in these mixtures. However, its crystallinity was reduced in the mixtures previously heated up to 155 °C and then cooled to 25 °C.

  • Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
    • Ireneusz Marzec
    • Jerzy Bobiński
    2022 Full text Materials

    Results of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity of the results with respect to the material parameters and the specimen geometry is investigated. Three different softening laws are examined. First, a bilinear softening definition is utilized. Then, an exponential curve is taken. Finally, a rational Bezier curve is tested. An ambiguity in choosing material parameters and sof-tening curve definitions is discussed. Numerical results are compared with experimental out-comes recently reported in the literature. Two error measures are defined and used to quantita-tively assess calculated maximum forces (nominal strengths) in comparison with experimental values as a primary criterion. In addition, the force—displacement curves are also analyzed. It is shown that all softening curves produce results consistent with the experimental data. Moreover, with different softening laws assumed, different initial fracture energies should be taken to obtain proper results.

  • Quantum security and theory of decoherence
    • Piotr Mironowicz
    2022 Full text NEW JOURNAL OF PHYSICS

    We sketch a relation between two crucial, yet independent, fields in quantum information research, viz. quantum decoherence and quantum cryptography. We investigate here how the standard cryptographic assumption of shielded laboratory, stating that data generated by a secure quantum device remain private unless explicitly published, is disturbed by the einselection mechanism of quantum Darwinism explaining the measurement process by interaction with the external environment. We illustrate the idea with a paradigmatic example of a quantum random number generator compromised by a quantum analog of the Van Eck phreaking. In particular, we derive a trade-off relation between the eavesdropper's guessing probability $\mathrm{P}_{\mathrm{guess}}$ and the collective decoherence factor Γ of the simple form $\mathrm{P}_{\mathrm{guess}} + \Gamma \geqslant 1$.

  • Quasi-Static Response
    • James Underwood
    • Erick Alley
    • Jerolim Andric
    • Dario Boote
    • Zhen Gao
    • Ad Van Hoeve
    • Jasmin Jelovica
    • Yasumi Kawamura
    • Yooil Kim
    • Jianhu Liu
    • Sime Malenica
    • Heikki Remes
    • Asokendu Samanta
    • Krzysztof Wołoszyk
    • Deqing Yang
    2022 Full text

    Concern for the quasi-static response of ship and offshore structures, as required for safety and serviceability assessments. Attention shall be given to uncertainty quantification of quasi-static load and response analysis approaches, and their limitations, including exact and approximate methods for derivation of different acceptance criteria.

  • Ranking ecosystem services delivered by trees in urban and rural areas
    • Patrycja Przewoźna
    • Krzysztof Mączka
    • Marcin Mielewczyk
    • Adam Inglot
    • Piotr Matczak
    2022 Full text AMBIO

    Policies and strategies for tree management and protection on a national, regional, and local level have not sufficiently considered differences between rural and urban areas. We used expert knowledge to compare rural and urban areas in a case study evaluating the relative importance of ecosystem services (ES) in policy development. The Analytic Hierarchy Process (AHP) and focus group discussions were used to rank 17 ES, representing four classes of services: provisioning, regulating, habitat, and cultural. The results indicated that effective protection strategies, beyond simply increasing general tree cover, should consider specific benefits trees provide to local communities. We discuss the role of objective prioritization of ES delivered by trees in urban and rural areas and their consequences for decision-making processes.

  • Rapid Design Centering of Multi-Band Antennas Using Knowledge-Based Inverse Models and Response Features
    • Michał Kozieł
    • Sławomir Kozieł
    2022 KNOWLEDGE-BASED SYSTEMS

    Accounting for manufacturing tolerances as well as uncertainties concerning operating conditions and material parameters is one of the important yet often neglected aspects of antenna development. Appropriate quantification of uncertainties allows for estimating the fabrication yield but also to carry out robust design (e.g., yield maximization). For reliability reasons, statistical analysis should be executed at the accuracy level of full-wave electromagnetic (EM) simulation. Unfortunately, the associated computational cost is normally unmanageable when using traditional methods, e.g., Monte Carlo (MC) simulation, in a brute force manner. Computationally tractable approaches are based on surrogate modeling techniques, where the fast metamodel is either used to run MC at low cost, or to directly extract statistical moments of the system output (e.g., polynomial chaos expansion). The bottleneck of surrogate-based frameworks is a potentially large number of training data samples necessary to render the surrogate, which may become problematic especially for higher-dimensional parameter spaces. This paper proposes a novel approach to design centering of multi-band antennas, which involves knowledge-based inverse regression models constructed at the level of appropriately-defined response features. Our methodology capitalizes on establishing—in the form of the inverse model—a functional relationship between the feature point coordinates affecting satisfaction of the prescribed design specification and geometry parameters of the antenna under analysis. The inverse model predicts the parameter vectors featuring improved likelihood of fulfilling the requirements under uncertainties. Due to low-dimensionality of the feature space, only a handful of EM analyses is necessary to render the model, which translates into a low cost of the entire design centering procedure. The presented algorithm is demonstrated using three microstrip antennas and favorably compared to several benchmark methods.

  • Rapid on-line method of wastewater parameters estimation by electronic nose for control and operating wastewater treatment plants toward Green Deal implementation
    • Grzegorz Łagód
    • Jakub Drewnowski
    • Ł. Guz
    • Adam Piotrowicz
    • Zbigniew Suchorab
    • Małgorzata Drewnowska
    • Katarzyna Jaromin-Gleń
    • Bartosz Szeląg
    2022 Desalination and Water Treatment

    In order to comply with legal regulations related to wastewater quality, the operational mode of facilities at wastewater treatment plant (WWTP) should be properly adjusted according to parameters of influents, however it is very difficult without frequently performed measurements. Currently there are known many techniques and devices for assesment of wastewater parameters such as chemical oxygen demand, biochemical oxygen demand, total organic carbon, as well as phosphorus and nitrogen compounds. In spite of the far reaching improvements of treatment process automatisation, there still isn’t developed a automatic and fast measuring system of wastewater parameters. Rapid on-line method of wastewater parameters estimation by electronic nose and computer simulations could be recomended as an alternative solution in many WWTPs in comparation with traditional approch. Within this paper the analysis of real-time data obtained from laboratory bioreactor were used to estimate wastewater parameters in order to develop the inexpensive and fast-responding measuring for the WWTPs. The elaborated method enables continuous and relatively low cost monitoring of the wastewater quality even in many key points of operating and control WWTP. In this context, computer simulation support with on-line e-nose measurments could be cheap and useful tool to improve the WWTP efficiency.