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Gdańsk University of Technology

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  • Kinetic analysis of the reduction of a ternary system of Bi, Sb and Te oxides by hydrogen for BiSbTe3 synthesis
    • Bartosz Trawiński
    • Bogusław Kusz
    2021 Full text THERMOCHIMICA ACTA

    Reduction in a hydrogen atmosphere of Bi2O3, Sb2O3 and TeO2 mixes oxides for the synthesis of BiSbTe3 was analysed. The reduction reactions of Sb2O3 and Sb2O4 oxides, as well as Bi2O3+Sb2O3 and Sb2O3+3TeO2 mix- tures, were also evaluated. The reduction of Sb2O4 is investigated for the first time. The reactions of the mixed oxides systems also were not the subject of research so far despite being used for synthesis of the (Bi,Sb)2Te3 material. The study comprised of kinetic analysis of TGA curves performed with non-parametric and iso- conversional methods. Insight into powders’ structure during the process was taken to identify processes taking place. The results show, that Sb2O3 present in the reduced oxidizes to Sb2O4. This redox process between Sb oxide and another oxide takes place directly. The self-heating effect caused by elemental tellurium is diminished in the presence of Bi, because Bi-Te phases decrease the content of the elemental Te.

  • Kinetics of the Organic Compounds and Ammonium Nitrogen Electrochemical Oxidation in Landfill Leachates at Boron-Doped Diamond Anodes
    • Barbara Wilk
    • Małgorzata Szopińska
    • Aneta Łuczkiewicz
    • Michał Sobaszek
    • Ewa Siedlecka
    • Sylwia Fudala-Książek
    2021 Full text Materials

    Electrochemical oxidation (EO) of organic compounds and ammonium in the complex matrix of landfill leachates (LLs) was investigated using three different boron-doped diamond electrodes produced on silicon substrate (BDD/Si)(levels of boron doping [B]/[C] = 500, 10,000, and 15,000 ppm—0.5 k; 10 k, and 15 k, respectively) during 8-h tests. The LLs were collected from an old landfill in the Pomerania region (Northern Poland) and were characterized by a high concentration of N-NH4+ (2069 ± 103 mg·L−1), chemical oxygen demand (COD) (3608 ± 123 mg·L−1), high salinity (2690 ± 70 mg Cl−·L−1, 1353 ± 70 mg SO42−·L−1), and poor biodegradability. The experiments revealed that electrochemical oxidation of LLs using BDD 0.5 k and current density (j) = 100 mA·cm−2 was the most effective amongst those tested (C8h/C0: COD = 0.09 ± 0.14 mg·L−1, N-NH4+ = 0.39 ± 0.05 mg·L−1). COD removal fits the model of pseudo-first-order reactions and N-NH4+ removal in most cases follows second-order kinetics. The double increase in biodegradability index—to 0.22 ± 0.05 (BDD 0.5 k, j = 50 mA·cm−2) shows the potential application of EO prior biological treatment. Despite EO still being an energy consuming process, optimum conditions (COD removal > 70%) might be achieved after 4 h of treatment with an energy consumption of 200 kW·m−3 (BDD 0.5 k, j = 100 mA·cm−2).

  • Klasyfikacja aktywności kory wzrokowej za pomocą elektroencefalografu
    • Jakub Atroszko
    2021

    W niniejszej pracy została przedstawiona metodologia konstrukcji i oceny systemu cyfrowego automatycznie klasyfikującego dane pochodzące z elektroencefalografu. Opracowana procedura badawcza pozwoliła na przetestowanie rozwiązania na różnych osobach, w różnym wieku, o różnych porach dnia, z wykorzystaniem różnych konfiguracji urządzeń i modeli zjawiska. Uzyskano stuprocentową skuteczność automatycznego rozpoznania stanu spoczynkowego kory wzrokowej. Architektura rozwiązania została oparta o algorytm maszyny wektorów nośnych, a także wektorowe reprezentacje aktywności mózgu utworzone z wykorzystaniem szybkiej transformacji Fouriera.

  • KLASYFIKACJA EMOCJI W MUZYCE FILMOWEJ Z WYKORZYSTANIEM TESTÓW SUBIEKTYWNYCH
    • Tomasz Ciborowski
    • Szymon Reginis
    • Adam Kurowski
    • Dawid Weber
    • Bożena Kostek
    2021 Full text

    Celem referatu było przedstawienie testów odsłuchowych, w których zadaniem osób ankietowanych było przypisanie danego fragmentu muzycznego do odpowiedniej klasy emocji. Kolejne kroki eksperymentu obejmowały wybór muzyki filmowej do testów (baza Epidemic Sound), przygotowanie założeń ankiety oraz modelu emocji wykorzystywanych w testach odsłuchowych, jak również konstrukcj ˛e ankiety. Ankieta została zrealizowana za pomoc ˛a formularzy Google. W ramach analizy wyników testów odsłuchowych w pierwszej kolejności sprawdzone zostały korelacje pomi ˛edzy parami klas emocji przypisanych do katalogów utworów w bazie Epidemic Sound. Nast ˛epnie zmapowano uzyskane wyniki ankiety na wykorzystany model, który zawiera emocje odniesienia (autorski model). W referacie zawarte też zostały histogramy zawieraj ˛ace przykłady list rankingowych przypisań kolorów do emocji. Przedstawiony również został zarys dalszych eksperymentów.

  • KLASYFIKACJA STANU TECHNICZNEGO UKŁADU WTRYSKOWEGO SILNIKA Z ZAPŁONEM SAMOCZYNNYM NA PODSTAWIE POMIARU SKŁADU SPALIN
    • Jacek Rudnicki
    • Jakub Bujczenko
    2021 Full text Journal of Polish CIMEEAC

    Artykuł przedstawia wyniki empirycznej weryfikacji hipotezy pozwalającej na opracowanie sprzętowo – programowego klasyfikatora stanu technicznego układu wtryskowego silnika z zapłonem samoczynnym. Pozytywna weryfikacja wspomnianej hipotezy, która wiąże przebieg procesu spalania, skład chemiczny spalin oraz wybrane stany niesprawności technicznej układu wtryskowego pozwoliła na przedstawienie koncepcji klasyfikatora w rozpatrywanym zbiorze klas stanu układu wtryskowego.

  • Klasyfikacja tekstu przy użyciu grafowych sieci neuronowych
    • Robert Benke
    2021

    Współczesnym algorytmom analizy tekstu wciąż daleko do ludzkiego poziomu jego zrozumienia. Jednym z wyzwań jest znajdowanie przez maszynę związków pomiędzy odległymi fragmentami tekstu. Próbą rozwiązania tego problemu są grafowe reprezentacje tekstu, które bardzo dobrze sprawdzają się w przedstawianiu złożonych zależności. W tekście opisane zostały dwie metody grafowej reprezentacji tekstu oraz algorytm grafowych konwolucyjnych sieci neuronowych.

  • Klasyfikator Adaboost w detekcji i rozpoznawaniu obiektów graficznych
    • Jerzy Dembski
    2021

    W pracy opisano metode Adaboost w zastosowaniu do detekcji obiektów graficznych, takich jak twarze lub rozpoznawania np. osób na podstawie obrazu twarzy. Przedstawiono podstawy algorytm, wersje kaskadowa, schemat przepływu danych i sterowania w zadaniu detekcji twarzy oraz sposoby adaptacji tej metody do problemów wieloklasowych. Opisano równiez zbiory cech obrazów, takie jak HAAR, LBP czy HOG stosowane w zadaniach detekcji i rozpoznawania obiektów graficznych.

  • Knowledge risks in organizations – Insights from companies
    • Małgorzata Zięba
    • Susanne Durst
    • Martyna Gonsiorowska
    • Zeynaddin Zralov
    2021 Full text

    Purpose: Knowledge risks are increasingly becoming a great challenge to a variety of organizations. At the same time, academic research on such types of risks, their consequences, and potential ways of overcoming them is still scarce and fragmented. To fill this gap, the paper aims to find out do companies manage their knowledge risks, what are the possible knowledge risks they face and have they observed an increase of knowledge risks during the COVID-19 pandemic. The paper is aimed to present insights on different types of knowledge risks that organizations face, and the ways organizations handle them. The paper also proposes some potential countermeasures organizations might use to mitigate the consequences of knowledge risks. Methodology: The study presents the results of a quantitative survey performed among 60 professionals dealing with management and knowledge risks in organizations. In the study, the authors also have examined what tools and methods are used to manage these risks. The study also explores the level of readiness organizations have to address potential knowledge risks. Findings: The theoretical study has allowed us to identify a variety of knowledge risks, which can bear severe consequences for organizations, such as knowledge loss, knowledge leaking, knowledge hiding, or risks related to cybercrime. All these risks may potentially reduce the productivity in organizations, thus leading to the degradation of organizational performance. Research limitations: Research results are limited to the convenience sample that was selected for the study and thus may not give a comprehensive overview of the state of the art. Practical implications: The study provides useful insights for managers and owners of organizations in need of dealing with the knowledge risks in their organizations. The paper is enriched with a number of sample solutions that they may apply for the sake of their organization. Originality/value: The paper lays the ground for a better understanding of the knowledge risks that organizations need to face nowadays. As such, the paper offers food for thought for researchers dealing with the topic of knowledge risks, knowledge management, and organizational risk management in general.

  • Knowledge Risks in the COVID-19 Pandemic
    • Małgorzata Zięba
    • Susanne Durst
    • Martyna Gonsiorowska
    2021 Full text

    This conceptual paper aims to identify, present, and analyse potential knowledge risks organizations face in external and dynamic crises such as the COVID-19 pandemic. Until only recently, many researchers and practitioners have perceived knowledge primarily as something positive. This view has changed recently with a growing number of studies highlighting risks related to knowledge. The on-going COVID-19 pandemic can be seen as an additional triggering point which has brought several new knowledge risks. Research on knowledge risks, their consequences and potential ways of handling them is still only in its beginning and consequently rather fragmented. To address this situation, this paper is aimed to provide some theoretical insights into knowledge risks and their possible implications organizations are exposed to in an external and dynamic crisis such as the COVID-19 crisis. To reach this aim, this paper presents a continuation of the research by Durst and Zieba from 2018 related to knowledge risks and their potential outcomes. This present study reviewed the up-dated literature on knowledge risks and uses the taxonomy proposed in the paper by Durst and Zieba to identify and analyse knowledge risks organizations are exposed to in the COVID-19 pandemics. Hence, the paper does not only offer fresh food for thought for researchers dealing with the topic of knowledge risks in the COVID-19 crisis and ways of handling them.

  • Knowledge Sharing in the COVID-19 Era of Remote Teaching: What Can Academia Learn from Business?
    • Krzysztof Zięba
    2021 Full text

    Purpose: The aim of this paper is to investigate how universities may benefit from experiences of businesses that were also forced to use remote forms of business operations. Methodology: The paper uses in-depth interviews to explore the possibilities of knowledge sharing improvements at the university-level teaching, based on the experiences elicited in the business sector. The theoretical sampling was used to find informants familiar with both transition to remote teaching and shift to online business operations forced by the COVID-19 pandemic. Findings: Interviews were conducted with experienced managers participating in an MBA programme. During the outburst of the COVID-19 pandemic the programme has been switched to a remote mode. At the same time, the interviewed managers had to cope with the transition to remote mode at work. Their work-related ordeals were contrasted and compared with their university-related experiences regarding knowledge sharing. Research limitations: This paper is of an exploratory character. The triangulation of findings presented here is limited. The sample consists of participants of one MBA programme only, hence the conclusions cannot be generalised. At this stage the paper may serve as a basis for further development. Practical implications: The paper presents possible improvements to be introduced by academia in the remote mode teaching. Business sector and especially large businesses may offer experience-based solutions that allow to boost knowledge sharing processes among students and increase the efficiency of knowledge sharing between teachers and students. Originality/value: The topic of the paper is very up-to-date and of considerable significance. Knowledge sharing processes at the university-level teaching have been significantly distorted by the COVID-19 pandemic outburst. Using experiences from the business sector can be very helpful in this regard.

  • Komputer w labiryncie
    • Michał Gleba
    • Grzegorz Godycki Ćwirko
    • Maryia Mankevich
    • Joanna Raczek
    2021 Full text Programista Junior

    Programiści piszą programy, które potrafią robić wiele różnych rzeczy: odtwarzać filmy, prognozować pogodę, pomagać w nauce języków obcych czy matematyki. Ale czy wiesz, że można zaprogramować komputer tak, aby tworzył labirynty? W dodatku takie, które zawierają tajne informacje!

  • Koncepcja Lean Management w uczelniach - przegląd wyników badań międzynarodowych
    • Piotr Grudowski
    2021

    W artykule przedstawiono rozważania dotyczące zastosowań koncepcji Lean Management w instytucjach szkolnictwa wyższego. Zaprezentowano odniesienia do charakterystycznych elementów i zasad tej koncepcji, przedstawione w piśmiennictwie międzynarodowym. Przedstawiono także szereg informacji wiążących się z LeanHE – rozwijającym się dynamicznie nurtem dotyczącym zastosowań Lean Management w szkolnictwie wyższym.

  • Kriging metamodels and design re‐utilization for fast parameter tuning of antenna structures
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2021 INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS

    The paper addresses the problem of computationally efficient electromagnetic (EM)‐driven design closure of antenna structures. The foundations of the presented approach are fast kriging interpolation metamodels, utilized for two purposes: (a) producing a good starting point for further parameter tuning, and (b) yielding a reasonable Jacobian matrix estimate to jump‐start the optimization procedure. The models are rendered using available designs, for example, obtained from the previous design work with the same antenna structure. The low cost of design closure is ensured by employing Broyden‐based trust‐region gradient search along with the aforementioned Jacobian initialization. Our methodology is demonstrated using two planar antennas, a dual‐band uniplanar dipole and a quasi‐Yagi with a parabolic reflector, both optimized within wide ranges of operating conditions (center frequencies, the dielectric permittivity of the antenna substrate). The re‐design process requires only a handful of EM analyses of the respective structure. The presented framework can be viewed as a convenient algorithmic tool that capitalizes on the existing information on the structure at hand to enable warm‐start parameter tuning.

  • Kształcenie kadr dla gospodarki wodnej na Wydziale Inżynierii Lądowej i Środowiska Politechniki Gdańskiej
    • Tomasz Kolerski
    2021 Full text Gospodarka Wodna

    Politechnika Gdańska jest częścią europejskiej i światowej wspólnoty akademickiej. Wspólnota Uczelni działa na rzecz podnoszenia dobrostanu społecznego oraz zrównoważenia ekosystemu Ziemi – we współpracy z uczelniami z Europy i świata, a także z podmiotami z innych sektorów. Kształcenie i edukacja realizowane są na 8 wydziałach w ramach 37 kierunków I i II stopnia. Blisko 1300 nauczycieli akademickich kształci przeszło 15 tysięcy studentów z ponad 70 krajów. Uczelnia jest na 2. miejscu w konkursie MNiSW oraz zajmuje 4. miejsce wśród uczelni technicznych w rankingu szkół wyższych miesięcznika Perspektywy. Politechnika Gdańska jest również dostrzegana w rankingach międzynarodowych w tym Academic Ranking of World Universities (Ranking Szanghajski) oraz w prestiżowym zestawieniu najlepszych uczelni na świecie – QS World University Rankings 2021. Politechnika Gdańska oferuje możliwości uzyskania stopnia doktora w dwóch jednostkach: szkole doktorskiej oraz szkole doktorskiej wdrożeniowej, które są bezpłatne, zapewniają stypendium, są interdyscyplinarne i zapewniają kreatywne i interdyscyplinarne podejście do badań. Absolwenci Politechniki Gdańskiej łatwo znajdują pracę i są zadowoleni z wybranej uczelni, a ich wynagrodzenie zalicza się do 1) Dr hab. inż. Tomasz Kolerski, prof. uczelni, Politechnika Gdańska, Wydział Inżynierii Lądowej i Środowiska. najwyższych w kraju. Potwierdzają to nie tylko wyniki corocznego badania losów zawodowych osób, które ukończyły studia na PG, ale i zestawienie przygotowane przez zewnętrzną firmę.

  • Kwasy nukleinowe - niedoceniane składniki żywności
    • Zuzanna Koziara
    • Anna Kościelak
    • Agnieszka Bartoszek-Pączkowska
    2021 Laboratorium

    Obecnie badania nad kwasami nukleinowymi koncentrują się na roli genetycznej tych makromolekuł. Można jednak przypuszczać, że DNA jak i RNA powszechnie występujące w żywności mają także ważne znaczenie żywieniowe. Świadczy o tym obecność w układzie pokarmowym szeregu mechanizmów odpowiedzialnych za detekcję, trawienie i przyswajanie tych składników pokarmu. W literaturze naukowej rośnie liczba doniesień sugerujących istotną rolę żywieniową spożywanych kwasów nukleinowych, ale wiedza ta jest daleka od uporządkowania i nie dostarcza jeszcze ugruntowanych poglądów, które mogłyby stanowić podstawę rekomendacji dietetycznych.

  • La Città Libera di Danzica: compromesso ragionevole o scommessa impossibile?
    • Luciano Segreto
    2021 Passato e presente. Rivista di storia contemporanea

    The article outlines the main economic ptoblems connected with the birth of the Free city of Danzig. In particular, it studies the complex relationships between the city, the Polish government, the League of Nations, and the Allies about the use of the port of Danzig and the increasing competition with the port of Gdynia, built by the Polish government with support of the French one and some french private companies.

  • Labour resources in Azerbeijan
    • Krystyna Gomółka
    2021

    The article aims to assess the changes of the Azerbaijani labour resources through deductive analysis of historical data and observation of changes in the structure of resources based on generally available macroeconomic data. Analysis shows that, during the period considered, the population of Azerbaijan increased, with a majority living in cities. Universal access to education enabled a growing group of Azerbaijanis to complete secondary education. The percentage of students increased by 35.17%. Following the retirement age increase, the number of economically active and employed people has grown. The unemployment rate, affecting particularly women, has also decreased. The positive migration balance has boosted labour resources since 2008, but the trend was halted by the COVID pandemic in 2020. Business closures have increased unemployment, whereas border closures reduced migration.

  • Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters
    • Waldemar Jendernalik
    • Jacek Jakusz
    • Grzegorz Blakiewicz
    2021 Full text Electronics

    Buffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more general method for uffer-based filter synthesis is developed and presented. The method uses RLC ladder prototypes to obtain filters of arbitrary orders. In addition, a set of novel circuit solutions with ultra-low voltage and power are proposed. The introduced circuits were synthesized and simulated using 180-nm CMOS technology of X-FAB. One of the designed circuits is a fourth-order, low-pass filter that features: 100-Hz passband, 0.4-V supply voltage, power consumption of less than 5 nW, and dynamic range above 60 dB. Moreover, the total capacitance of the proposed filter (31 pF) is 25% lower compared to the structure synthesized using a conventional cascade method (40 pF).

  • Lagrangian model of an isolated dc-dc converter with a 3-phase medium frequency transformer accounting magnetic cross saturation
    • Piotr Dworakowski
    • Andrzej Wilk
    • Michał Michna
    • Alexis Fouineau
    • Martin Guillet
    2021 Full text IEEE TRANSACTIONS ON POWER DELIVERY

    This article presents a nonlinear equivalent circuit model of an isolated dc-dc converter with a 3-phase medium frequency transformer. The model takes into account the magnetic cross saturation of the 3-phase core-type magnetic circuit. The model is suitable in detailed electromagnetic transient simulations of power systems involving isolated dc-dc converters. The model is developed using the Lagrange energy method. It involves a matrix of dynamic inductances containing a nonlinear term resulting from core magnetization and a linear term resulting from leakage flux. The model parameters are determined based on a series of magnetostatic finite element method simulations. This approach is convenient when applied to high power transformers offering a limited characterization effort, or if the transformer prototype does not exist. The experimental validation performed on a novel 3-phase MFT prototype in a 100kW 1.2kV 20kHz dual active bridge converter has proved the validity of the model and model parameters. The no-load steady-state and inrush tests and the full-load test show a very good fit between the simulated and experimentally measured waveforms. The comparison with a classical simplified model neglecting magnetic cross saturation shows a significant difference in the no-load inrush test.

  • Landscape as a Potential Key Concept in Urban Environmental Planning: The Case of Poland
    • Aleksandra Sas-Bojarska
    2021 Full text Urban Planning

    Rapid urban development increases the consumption of materials, energy, and water, resulting in an overproduction of waste and emissions. These cause many environmental threats, such as ozone layer depletion and rain acidification, leading to climate change. Therefore, the question arises on how to improve the effectiveness of tools that strengthen environmental protection. This discursive article presents an approach stressing the role of landscape in environmental protection in Poland. It indicates that landscape protection is an ecological, not just an aesthetic activity, as it is often considered in Poland. The landscape reflects all changes occurring in individual elements of the environment resulting from urban development. Through landscape transformations, one can track the growth and accumulation of adverse effects in the chain of environmental changes. Knowledge regarding the dynamics and scope of these transformations can improve ecological design and technologies. Therefore, the landscape condition should be treated as an indicator of sustainable development. If so, one could hypothesise that effective landscape protection contributes to minimising environmental and climate changes. The relationships between the landscape and environmental/climate threats discussed in this article prompt combining some tools related to these threats, which may ensure both effective landscape protection and sustainable development, leading to reduced climate change. The possibilities and benefits of integrating these tools are presented here as well. General considerations are supplemented with references to the situation in Poland to support the need for implementing a more policy-oriented and interdisciplinary approach to landscape protection.

  • Large Hall and Nernst responses from thermally induced spin chirality in a spin-trimer ferromagnet
    • Kamil Kolincio
    • Max Hirschberger
    • Jan Masell
    • Shang Gao
    • Akiko Kikkawa
    • Yasujiro Taguchi
    • Taka-hisa Arima
    • Naoto Nagaosa
    • Yoshinori Tokura
    2021 Full text PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

    The long-range order of noncoplanar magnetic textures with scalar spin chirality (SSC) can couple to conduction electrons to produce an additional (termed geometrical or topological) Hall effect. One such example is the Hall effect in the skyrmion lattice state with quantized SSC. An alternative route to attain a finite SSC is via the spin canting caused by thermal fluctuations in the vicinity of the ferromagnetic ordering transition. Here, we report that for a highly conducting ferromagnet with a two-dimensional array of spin trimers, the thermally generated SSC can give rise to a gigantic geometrical Hall conductivity even larger than the intrinsic anomalous Hall conductivity of the ground state. We also demonstrate that the SSC induced by thermal fluctuations leads to a strong response in the Nernst effect. A comparison of the sign and magnitude of fluctuation–Nernst and Hall responses in fundamental units indicates the need for a momentum–space picture to model these thermally induced signals.

  • Laser-assisted approach for improved performance of Au-Ti based glucose sensing electrodes
    • Adrian Olejnik
    • Gerard Śliwiński
    • Jakub Karczewski
    • Jacek Ryl
    • Katarzyna Siuzdak
    • Katarzyna Grochowska
    2021 APPLIED SURFACE SCIENCE

    This paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60–90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working laser parameters that allow for fabrication of material possessing the highest performance towards glucose oxidation. It is proven that laser-engineered electrodes have an improved stability in acidic conditions and higher response from glucose oxidation in both alkaline and neutral environment in comparison to analogs obtained by conventional furnace dewetting. In neutral electrolyte it is also observed that the current density increases by almost 300% while the change in mechanism of glucose oxidation was identified due to laser treatment. It is suggested that laser dewetted gold nanoparticles have more surface defects than furnace dewetted ones so that more AuOHads species are created and therefore catalytic activity of the material is enhanced. These results indicate a scalable and cost-effective fabrication route and are important for the current research on nonenzymatic glucose sensors.

  • Lateral load resistance of piled raft foundation - A case study of District Jail, Saidu Sharif, Swat Pakistan
    • Irfan Jamil
    • Irshad Khan
    • Maaz Amjad
    • Mahmood Ahmad
    • Umar Farooq
    • Tayyaba Bibi
    2021 Full text International Journal of Applied Engineering Research (Netherlands)

    Piled raft foundations under lateral loads are usually designed as a pile group, ignoring the contribution of the raft to resisting the lateral loads. In this paper, a case study was performed to determine the raft's contribution to the lateral load resistance. This study analyzed a pile-supported reinforced concrete retaining wall for two different foundation conditions, i.e., pile group foundation and pile raft foundation. Pile group supported reinforced concrete retaining wall was analyzed by following the standard code practice while pile raft supported reinforced concrete retaining wall was analyzed with the help of up-to-the-minute finite element-based software, PLAXIS 3D. It was revealed that by considering the contribution of the raft in the pile raft foundation system subjected to lateral loads, a great deal of economy can be achieved in terms of the small diameter of piles, short pile lengths and less number of piles. The maximum moment on piles was decreased about 2.5-3 times while the maximum shear was decreased about 2-3 times. A decrease in demand also results in reducing the lateral deflection of piles to about 50 %.

  • Latest Insights on Novel Deep Eutectic Solvents (DES) for Sustainable Extraction of Phenolic Compounds from Natural Sources
    • Julio Serna-vázquez
    • Mohd Zamidi Ahmad
    • Grzegorz Boczkaj
    • Roberto Castro-Muñoz
    2021 Full text MOLECULES

    Phenolic compounds have long been of great importance in the pharmaceutical, food, and cosmetic industries. Unfortunately, conventional extraction procedures have a high cost and are time consuming, and the solvents used can represent a safety risk for operators, consumers, and the environment. Deep eutectic solvents (DESs) are green alternatives for extraction processes, given their low or non-toxicity, biodegradability, and reusability. This review discusses the latest research (in the last two years) employing DESs for phenolic extraction, solvent components, extraction yields, extraction method characteristics, and reviewing the phenolic sources (natural products, by-products, wastes, etc.). This work also analyzes and discusses the most relevant DES-based studies for phenolic extraction from natural sources, their extraction strategies using DESs, their molecular mechanisms, and potential applications.

  • LE STIME ECONOMICHE DELLA CIA E L’IMPREVEDIBILE FINE DELL’URSS
    • Luciano Segreto
    2021 Studi Storici

    In this article, we will analyze the debate that took place around the assessments that the CIA gave of the economic situation in the Soviet Union, a clearly decisive key to understanding the overall health of the main political-military opponent of the United States. The article will include the discussions that flared up in the American political establishment starting in 1990, after the fall of the Berlin Wall and the initial disorientation due to the loss of the historical adversary of the Cold War. Moreover, the positions taken by sovietologists in these discussions will be evaluated, as well as the role played in these debates by the analysis developed by Soviet economists in the 1980s. We will lastly consider the official response provided by the CIA (a response that, coming only in 2001, was actually rather slow to arrive), aimed essentially at confirming the correctness of its analyses and reiterating that its duties did not include that of predicting the collapse of the Soviet Union.

  • Leadership, culture, intellectual capital and knowledge processes for organizational innovativeness across industries: the case of Poland
    • Wioleta Kucharska
    2021 Full text Journal of Intellectual Capital

    Purpose – This study aims to present the overview of intellectual capital creation micro-mechanisms concerning formal and informal knowledge processes. The organizational culture, transformational leadership and innovativeness are also included in the investigation as ascendants and consequences of the focal relation of intellectual capital and knowledge processes. Design/methodology/approach – Based on a sample of 1,418 Polish knowledge workers from the construction, healthcare, higher education and information technology (IT) industries, the empirical model was developed using the structural equation modeling (SEM) method. Findings – The study exposes that the essence of transformational leadership innovativeness oriented is developing all intellectual capital components. To do so, leaders must support both formal and informal knowledge processes through the organizational culture of knowledge and learning. Furthermore, for best results of the knowledge transformation into intellectual capital, the learning culture must be shaped by both components: learning climate and acceptance of mistakes. Practical implications – Presented findings can be directly applied to organizations to enhance innovativeness. Namely, leaders who observe that the more knowledge is formally managed in their organizations, the less effective the knowledge exchange is-should put more effort into supporting informal knowledge processes to smoothly develop human and relational intellectual capital components. Shortly, leaders must implement an authentic learning culture, including the mistakes acceptance component, to use the full organizational potential to achieve intellectual capital growth. Intellectual capital growth is essential for innovativeness. Originality/value – This study presents the “big picture” of all intellectual capital creation micromechanisms linking transformational leadership with organizational innovativeness and explains the “knowledge paradox” identified by Mabey and Zhao (2017). This explanation assumes that intellectual capital components are created informally (i.e. human and relational ones) and formally (i.e. structural ones). Therefore, for best effects, both formal and informal knowledge processes, must be supported. Furthermore, this study exposes that the intensity of all explored micro-mechanisms is industry-specific

  • Leveraging spatio-temporal features for joint deblurring and segmentation of instruments in dental video microscopy
    • Efkleidis Katsaros
    • Anna Jezierska
    • Daniel Węsierski
    2021

    In dentistry, microscopes have become indispensable optical devices for high-quality treatment and micro-invasive surgery, especially in the field of endodontics. Recent machine vision advances enable more advanced, real-time applications including but not limited to dental video deblurring and workflow analysis through relevant metadata obtained by instrument motion trajectories. To this end, the proposed work addresses dental video deblurring and instrument segmentation in a Multi-task Learning fashion, leveraging spatio-temporal adaptive kernels via a recurrent design. The task-specific branches of our architecture employ the responses of those kernels to recover sharper video frames and yield the dental instrument segmentation mask. We demonstrate that the proposed method improves deblurring while retaining segmentation performance under a low computational footprint.

  • Licencjonowanie oprogramowania
    • Tomasz Boiński
    • Szymon Olewniczak
    2021 Full text

    Wolne i otwarte oprogramowanie przeżywa ostatnimi laty rozkwit. Co raz więcej przedsiębiorstw komercyjnych opiera rozwój swoich firm na otwartym oprogramowaniu. Zarówno mali, jak i duzi gracze mają świadomość komplikacji współczesnych systemów i niemożności samodzielnego ich rozwoju. Z pomocą przychodzi otwarte podejście do wytwarzania oprogramowania. Wymaga to jednak pewnego zrozumienia uwarunkowań prawnych, a w szczególności licencji, na jakich wydawane jest oprogramowanie. Niniejsze opracowanie ma na celu omówienie tychże uwarunkowań, odpowiada na pytanie dlaczego potrzebujemy licencji na oprogramowanie. Opisywane zostały również najważniejsze wg autorów licencje, oraz wskazuje, czym należy kierować się przy doborze licencji.

  • Lighting Design for the 21st Century Applied research in lighting practice
    • Karolina Zielińska-Dąbkowska
    2021 Full text ARC Lighting In Architecture

    For those who are unfamiliar with research, it’s important to know there are two categories. Fundamental (or basic) research and applied research. Basic research often discusses scientific ideas/theories, whereas, applied research explores testing these ideas in practice to develop technology or techniques. It’s applied research which most interests lighting practitioners. Great lighting design that creates a pleasant and beneficial user experience in any given space doesn’t just occur miraculously. Rather, it’s built on the designer’s insights and understanding, which comes from sound research and years of practice. This awareness comes from knowing the end users, as well as comprehending what’s best for them. In my view, there are three key research topics for the future of our lighting design profession that we should become familiar with. They are all based on the mounting research about daylight and artificial light and its impact on circadian relevance and biological stimulus. These are: (1) Environmental impact and light pollution, (2) Biophilic office design and (3) User oriented daylight integrated lighting (DIL). These topics have been demonstrated below by some pioneering project examples, where research has been performed to help derive outstanding results.

  • Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye
    • Rafal Luchowski
    • Wojciech Grudzinski
    • Renata Welc
    • Maria Manuela Mendes Pinto
    • Alicja Sek
    • Jan Ostrowski
    • Łukasz Nierzwicki
    • Paweł Chodnicki
    • Miłosz Wieczór
    • Karol Sowinski
    • Robert Rejdak
    • Anselm G. M. Juenemann
    • Grzegorz Teresinski
    • Jacek Czub
    • Wieslaw Gruszecki
    2021 Full text JOURNAL OF PHYSICAL CHEMISTRY B

    The functioning of the human eye in the extreme range of light intensity requires a combination of the high sensitivity of photoreceptors with their photostability. Here, we identify a regulatory mechanism based on dynamic modulation of light absorption by xanthophylls in the retina, realized by reorientation of pigment molecules induced by trans–cis photoisomerization. We explore this photochemically switchable system using chromatographic analysis coupled with microimaging based on fluorescence lifetime and Raman scattering, showing it at work in both isolated human retina and model lipid membranes. The molecular mechanism underlying xanthophyll reorientation is explained in terms of hydrophobic mismatch using molecular dynamics simulations. Overall, we show that xanthophylls in the human retina act as “molecular blinds”, opening and closing on a submillisecond timescale to dynamically control the intensity of light reaching the photoreceptors, thus enabling vision at a very low light intensity and protecting the retina from photodegradation when suddenly exposed to strong light.

  • Linkages between services and manufacturing as a new channel for GVC development: Evidence from CEE countries
    • Aleksandra Kordalska
    • Magdalena Olczyk
    2021 Full text Structural Change and Economic Dynamics

    The goal of the paper is to verify a causal relationship between forward linkages from domestic services to manufacturing and the participation/position of a country in global value chains (GVCs) in selected Central and Eastern European economies. We observed a strong polarisation pattern: the Baltic countries along with the Czech Republic strengthen their positions and participation in GVCs by having a strong relationship between the financial sector and manufacturing, while Poland, Hungary, and Slovakia have solid linkages between transportation services and manufacturing. We also discover that the reverse relationship is significant.

  • Load capacity of steel-aluminium brackets under static and cyclic laboratory tests
    • Andrzej Ambroziak
    2021 Full text Archives of Civil Engineering

    The aim of the research is the laboratory investigation of steel-aluminium brackets employed to fasten lightweight curtain walls to building facilities. Static pressure, suction forces, and cyclic loads parallel to end plates (horizontal – to simulate wind influence) were applied in the study. The steel-aluminium brackets were tested on a reinforced concrete substrate made of C30/37 concrete class to simulate the real working conditions. Laboratory tests were performed to failure of the brackets or damage of anchoring fastened to the concrete elements. Additionally, the tensile capacity of stainless steel bolt connections screwed in aluminium profile was determined. The uniaxial tensile tests were performed for three length variants of the anchorage: 28 mm, 14 mm, and 7 mm of the stainless steel bars screw-in in threading aluminium profiles. In the course of cyclic tests, a hinge formed in the location of bolt connections made the change of the working character of steel-aluminium brackets. The cyclic tests also showed the danger of the strap aluminium profile displacement due to improper connection with the main aluminium profile. The paper is intended to provide scientists, civil engineers, and designers with an experimental assessment of mechanical properties of steel-aluminium brackets under static and cyclic loads.

  • Local material symmetry group for first- and second-order strain gradient fluids
    • Victor Eremeev
    2021 Full text MATHEMATICS AND MECHANICS OF SOLIDS

    Using an unified approach based on the local material symmetry group introduced for general first- and second-order strain gradient elastic media, we analyze the constitutive equations of strain gradient fluids. For the strain gradient medium there exists a strain energy density dependent on first- and higher-order gradients of placement vector, whereas for fluids a strain energy depends on a current mass density and its gradients. Both models found applications to modeling of materials with complex inner structure such as beam-lattice metamaterials and fluids at small scales. The local material symmetry group is formed through such transformations of a reference placement which cannot be experimentally detected within the considered material model. We show that considering maximal symmetry group, i.e. material with strain energy that is independent of the choice of a reference placement, one comes to the constitutive equations of gradient fluids introduced independently on general strain gradient continua.

  • Locust bean gum as green and water-soluble binder for LiFePO4 and Li4Ti5O12 electrodes
    • Paweł Jakóbczyk
    • Michał Bartmański
    • Ewelina Rudnicka
    2021 Full text JOURNAL OF APPLIED ELECTROCHEMISTRY

    Locust Bean Gum (LBG, carob bean gum) was investigated as an environmentally friendly, natural, and water-soluble binder for cathode (LFP) and anode (LTO) in lithium-ion batteries (Li-ion). For the frst time, we show LBG as an electrode binder and compare to those of the most popular aqueous (CMC) and conventional (PVDF) binders. The electrodes were characterized using TGA/DSC, the galvanostatic charge–discharge cycle test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Thermal decomposition of LBG is seen to begin above 250 °C with a weight loss of about 60 wt% observed at 300 °C, which is sufcient to ensure stable performance of the electrode in a Li-ion battery. For CMC, weight loss at the same temperature is about 45%. Scanning electron microscopy (SEM) shows that the LFP–LBG system has a similar distribution of conductive carbon black particles to PVDF electrodes. The LTO–LBG electrode has a homogeneous dispersion of the electrode elements and maintains the electrical integrity of the network even after cycling, which leads to fast electron migration between LTO and carbon black particles, as well as ion conductivity between LTO active material and electrolyte, better than in systems with CMC and PVDF. The exchange current density, obtained from impedance spectroscopy fell within a broad range between 10−4 and 10−2 mA cm−2 for the LTO|Li and LFP|Li systems, respectively. The results presented in this paper indicate that LBG is a new promising material to serve as a binder.

  • Long-Term Impact of Wind Erosion on the Particle Size Distribution of Soils in the Eastern Part of the European Union
    • Lenka Lackóová
    • Jozefína Pokrývková
    • Jana Kozlovsky Dufková
    • Agnieszka Policht-Latawiec
    • Krystyna Michałowska
    • Jolanta Dąbrowska
    2021 Full text ENTROPY

    Wind erosion is the leading cause of soil degradation and air pollution in many regionsof the world. As wind erosion is controlled by climatic factors, research on this phenomenon isurgently needed in soil and land management in order to better adapt to climate change. In thispaper, the impact of wind erosion on the soil surface in relation to particle size distribution wasinvestigated. Changes in percentage of sand, silt and clay fractions based on historical KPP data(1961–1970), LUCAS data base (2009), and field measurements (2016) were analysed in five cadastralareas impacted by wind erosion (Záhorie Lowlands, Slovakia). With the use of GIS tools, models ofspatial distribution of sand, silt, clay and erodible fraction (EF) content were developed based onthose measurements. Our findings proved that soil texture change driven by wind erosion couldhappen relatively quickly, and a significant proportion of soil fine particles may be carried awaywithin a few years. The results indicate that the soil surface became much rougher over the period ofmore than 50 years, but also that the accumulation of fraction of the silt particles occurred in most ofthe areas affected by the erosive effect.Keywords:aeolian erosion; land degradation; GIS; sustainable agroecosystems; decision-makingprocesses; soil protection; wind erosion indicators; landscape entropy and stability1. IntroductionSoil erosion is a major cause of global-scale land degradation, and has increased by2.5% between 2001 and 2012. The main reasons for this increase are considered to be defor-estation and cropland expansion [1,2]. Soil erosion by wind is the process of destruction,separation, transportation and deposition of soil particles that affects negatively land andhuman health, agricultural production, as well as ecosystem services [3–5]. The process iscontrolled by several factors such as: wind speed and direction, temperature, precipitation,soil wetness, surface roughness, soil texture and aggregation, soil organic matter, vegetationcover, field size, agricultural activities and protective measures [6,7].

  • Looking Up to the Stars. A Call for Action to Save New Zealand’s Dark Skies for Future Generations to Come
    • Karolina Zielińska-Dąbkowska
    • Kyra Xavia
    2021 Full text Sustainability

    The rapid development of technology coupled with humanity’s desire to reach beyond terra firma, has resulted in more than 60 years of Outer Space activities. Although the exploration of space has provided many advantages and benefits to society so far, including vast, new information that has greatly added to our understanding of our planet and beyond, unfortunately, mankind’s footprint has negative aspects that need to be minimised as much as possible. In recent decades, a major worldwide problem has emerged in regard to the significant increase in light pollution from ground-based illuminations, as well as a lack of proper regulatory frameworks to mitigate the issue in order to protect the night sky and astronomical research. More recently, due to the escalating demand of air space for microsatellites and the rapid development of these new space technologies, as well as unmanned aerial vehicles (UAV), a new problem has arisen connected to visual light pollution (VLP). New Zealand has been especially affected, as, because of its dark skies, it has the third highest number of astronomical observatories in the world. The aim of this research is to identify critical areas for broader investigation; an action plan to improve the impact of new technologies is urgently required, not only at a national level but also worldwide. This is crucial in order to preserve humanity’s right to access the night sky and to also enable continual professional and amateur night-time observations for the present and the future, as well as for New Zealand to become a Dark Sky Nation.

  • Low-coherence photonic method of electrochemical processes monitoring
    • Monika Kosowska
    • Paweł Jakóbczyk
    • Michał Rycewicz
    • Alex Vitkin
    • Małgorzata Szczerska
    2021 Full text Scientific Reports

    We present an advanced multimodality characterization platform for simultaneous optical and electrochemical measurements of ferrocyanides. Specifcally, we combined a fber-optic Fabry– Perot interferometer with a three-electrode electrochemical setup to demonstrate a proof-ofprinciple of this hybrid characterization approach, and obtained feasibility data in its monitoring of electrochemical reactions in a boron-doped diamond flm deposited on a silica substrate. The flm plays the dual role of being the working electrode in the electrochemical reaction, as well as afording the refectivity to enable the optical interferometry measurements. Optical responses during the redox reactions of the electrochemical process are presented. This work proves that simultaneous opto-electrochemical measurements of liquids are possible.

  • Low-Cost Modeling of Microwave Components by Means of Two-Stage Inverse/Forward Surrogates and Domain Confinement
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Ullah Ubaid
    2021 Full text IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    Full-wave electromagnetic (EM) analysis is one of the most important tools in the design of modern microwave components and systems. EM simulation permits reliable evaluation of circuits at the presence of cross-coupling effects or substrate anisotropy, as well as for accounting for interactions with the immediate environment. However, repetitive analyses required by EM-driven procedures, such as parametric optimization or statistical analysis, may entail considerable computational expenditures, often prohibitive. Tackling the high-cost issue fostered the shift toward the incorporation of fast replacement models, including both physics-based surrogates and data-driven ones. While the latter is more popular and versatile, the construction of reliable approximation metamodels for microwave components is hindered by the curse of dimensionality and nonlinearity of system responses. The recent performance-driven modeling methodologies are capable of alleviating these difficulties by confining the surrogate domain to a vicinity of the optimum design manifold (i.e., the region that contains high-quality designs rather than the entire parameter space). Although setting up the model in a constrained domain requires small amounts of training data, domain definition itself requires a set of preoptimized reference designs, acquisition of which is an expensive endeavor. This work proposes a novel approach, which replaces the reference designs with a small set of random observables, thereby considerably reducing the overall cost of the model setup. Comprehensive verification involving several miniaturized microstrip structures demonstrates that our methodology is competitive to performance-driven frameworks both in terms of modeling accuracy and computational efficiency with an average savings of around 80%.

  • Low-cost multi-criterial design optimization of compact microwave passives using constrained surrogates and dimensionality reduction
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Muath Al-hasan
    2021 Full text INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS

    Design of contemporary microwave circuits is a challenging task. Typically, it has to take into account several performance requirements and constraints. The design objectives are often conflicting and their simultaneous improvement may not be possible; instead, compromise solutions are to be sought. Representative examples are miniaturized microwave passives where reduction of the circuit size has a detrimental effect on its electrical characteristics. Acquiring information about the best possible design trade‐offs is invaluable for the designer, yet it entails computationally expensive multi‐objective optimization (MO). MO is typically conducted using population‐based metaheuristic algorithms, the cost of which might be extremely high. If the circuit performance is evaluated using full‐wave electromagnetic (EM) analysis, this cost is often prohibitive. A workaround is the employment of fast surrogate models, and a number of surrogate‐assisted frameworks have been proposed in the literature. Unfortunately, a construction of reliable surrogates is hindered in higher dimensional parameter spaces. The recently proposed constrained modeling mitigates this issue to a certain extent by restricting the modeling process to the region containing the Pareto front to be found. This work proposes a novel surrogate‐based MO technique that involves constrained modeling and explicit reduction of the surrogate domain dimensionality. The latter is achieved through the spectral analysis of the extreme Pareto‐optimal design set obtained by local search routines. Our methodology is validated using a 15‐parameter impedance‐matching transformer with the Pareto set identified at the cost of a few hundred EM analyses of the circuit. The numerical experiments also demonstrate a significant reduction of the optimization cost as compared to the state‐of‐the‐art surrogate‐assisted MO methods.

  • Low-Cost Unattended Design of Miniaturized 4 × 4 Butler Matrices with Nonstandard Phase Differences
    • Adrian Bekasiewicz
    • Sławomir Kozieł
    2021 Full text SENSORS

    Design of Butler matrices dedicated to Internet of Things and 5th generation (5G) mobile systems—where small size and high performance are of primary concern—is a challenging task that often exceeds capabilities of conventional techniques. Lack of appropriate, unified design approaches is a serious bottleneck for the development of Butler structures for contemporary applications. In this work, a low-cost bottom-up procedure for rigorous and unattended design of miniaturized 4 × 4 Butler matrices is proposed. The presented approach exploits numerical algorithms (governed by a set of suitable objective functions) to control synthesis, implementation, optimization, and fine-tuning of the structure and its individual building blocks. The framework is demonstrated using two miniaturized matrices with nonstandard output-port phase differences. Numerical results indicate that the computational cost of the design process using the presented framework is over 80% lower compared to the conventional approach. The footprints of optimized matrices are only 696 and 767 mm2, respectively. Small size and operation frequency of around 2.6 GHz make the circuits of potential use for mobile devices dedicated to work within a sub-6 GHz 5G spectrum. Both structures have been benchmarked against the state-of-the-art designs from the literature in terms of performance and size. Measurements of the fabricated Butler matrix prototype are also provided.

  • Low-power microwave-induced fabrication of functionalised few-layer black phosphorus electrodes: A novel route towards Haemophilus Influenzae pathogen biosensing devices
    • Paweł Jakóbczyk
    • Marcin Kowalski
    • Mateusz Brodowski
    • Anna Dettlaff
    • Bartłomiej Dec
    • Dawid Nidzworski
    • Jacek Ryl
    • Tadeusz Ossowski
    • Robert Bogdanowicz
    2021 Full text APPLIED SURFACE SCIENCE

    In this paper, various passivation schemes were applied at few-layer black phosphorus (FLBP) to achieve covalent functionalisation with 4-azidobenzoic acid, improving its electrochemical response intended for analytical and biosensing applications. The thermal and microwave assisted modification procedures in toluene and dime-thylformamide resulted in high reversibility of reactions on functionalised FLBP using a ferricyanide/ferrocya-nide redox probe. The lowest peak-to-peak separation of 91 mV, and high kinetics were obtained by thermal synthesis in dimethylformamide. Attachment of a =N-phenylene-COOH moiety to the FLBP limits its degradation under ambient conditions delivering a linker for a peptide bond with proteins in the –NH2 groups. The functionalised FLBP was applied for impedimetric detection of the Haemophilus Influenzae (HI) bacterial protein with a low limit of detection (LOD) of 5.82 μg mL-1 along with high sensitivity equal to 1.267% μg-1 mL. The proposed strategy delivers a novel phosphorene-based electrode for sensitive detection of various bacterial pathogens.

  • Low-strain sensor based on the flexible boron-doped diamond-polymer structures
    • Michał Rycewicz
    • Mateusz Ficek
    • Krzysztof Gajewski
    • Srinivasu Kunuku
    • Jakub Karczewski
    • Teodor Gotszalk
    • I. Wlasny
    • Andrzej Wysmołek
    • Robert Bogdanowicz
    2021 Full text CARBON

    A free-standing high boron-doped diamond nanosheet (BDDNS) has been fabricated for the development of a flexible BDDNS strain senor. High boron-doped diamond was initially grown on a tantalum substrate in a microwave plasma-assisted chemical vapor deposition method, and was then transferred to a Kapton polymer substrate to fabricate the flexible BDDNS/Kapton device. Before performing the transfer process, the thin BDDNS’s morphology and bonding structure on the top and bottom surfaces were investigated using scanning electron microscopy and Raman spectroscopy. The contact potential difference and work function values of the BDDNS top and bottom surfaces were measured using a Kelvin probe atomic force microscope. Significant electrical conducting properties were observed from the resistance mapping of the BDDNS foil, and the average resistance value of 31 Ω attained from the top surface of the BDDNS foil. The electrical response of the BDDNS/Kapton device was investigated using a custom-made measurement system and a positive residual resistance change with strain was observed. The developed BDDNS/Kapton device was able to sustain for measuring up to 0.55% of strain, which indicates it may have great potential to be utilized in low-strain sensor applications.

  • Machine Learning and Electronic Noses for Medical Diagnostics
    • Wojciech Wojnowski
    • Kaja Kalinowska
    2021

    The need for noninvasive, easy-to-use, and inexpensive methods for point-of-care diagnostics of a variety of ailments motivates researchers to develop methods for analyzing complex biological samples, in particular human breath, that could aid in screening and early diagnosis. There are hopes that electronic noses, that is, devices based on arrays of semiselective or nonselective chemical sensors, can fill this niche. Electronic olfaction uses data processing and machine learning to build classification models based on the responses of several sensors in the form of multivariate datasets in order to discriminate between disease and healthy control based on a unique fingerprint. However, the introduction of this technique in clinical settings is limited by methodological issues which can, to some extent, be remedied using artificial intelligence. In this chapter, we provide a brief introduction to the electronic nose technique and outline its applications in medical diagnostics. We also discuss the ways in which data processing and machine learning techniques can be used to facilitate the use of electronic olfaction in the detection of disease.

  • MACHINE LEARNING APPLICATIONS IN RECOGNIZING HUMAN EMOTIONS BASED ON THE EEG
    • Adrian Kastrau
    • Michał Koronowski
    • Mariusz Liksza
    • Patryk Jasik
    2021

    This study examined the machine learning-based approach allowing the recognition of human emotional states with the use of EEG signals. After a short introduction to the fundamentals of electroencephalography and neural oscillations, the two-dimensional valence-arousal Russell’s model of emotion was described. Next, we present the assumptions of the performed EEG experiment. Detail aspects of the data sanitization including preprocessing, feature extraction, and target variable creation were also given. At the modeling stage, we created several classification models to establish a benchmark ranking of the problem related to the recognition of human emotions. Such a methodological approach enabled us to confirm that it is possible to build machine learning solutions allowing to recognize and classify human emotions with very high accuracy of over 90%.

  • Machine-Learning-Powered EM-Based Framework for Efficient and Reliable Design of Low Scattering Metasurfaces
    • Sławomir Kozieł
    • Muhammad Abdullah
    2021 Full text IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    Popularity of metasurfaces has been continuously growing due to their attractive properties including the ability to effectively manipulate electromagnetic (EM) waves. Metasurfaces comprise optimized geometries of unit cells arranged as a periodic lattice to obtain a desired EM response. One of their emerging application areas is the stealth technology, in particular, realization of radar cross section (RCS) reduction. Despite potential benefits, a practical obstacle hindering widespread metasurface utilization is the lack of systematic design procedures. Conventional approaches are largely intuition-inspired and demand heavy designer's interaction while exploring the parameter space and pursuing optimum unit cell geometries. Not surprisingly, these are unable to identify truly optimum solutions. In this article, we introduce a novel machine-learning-based framework for automated and computationally efficient design of metasurfaces realizing broadband RCS reduction. Our methodology is a three-stage procedure that involves global surrogate-assisted optimization of the unit cells, followed by their local refinement. The last stage is direct EM-driven maximization of the RCS reduction bandwidth, facilitated by appropriate formulation of the objective function involving regularization terms. The appealing feature of the proposed framework is that it optimizes the RCS reduction bandwidth directly at the level of the entire metasurface as opposed to merely optimizing unit cell geometries. Computational feasibility of the optimization process, especially its last stage, is ensured by high-quality initial designs rendered during the first two stages. To corroborate the utility of our procedure, it has been applied to several metasurface designs reported in the literature, leading to the RCS reduction bandwidth improvement by 15%-25% when compared with the original designs. Furthermore, it was used to design a novel metasurface featuring over 100% of relative bandwidth. Although the procedure has been used in the context of RCS design, it can be generalized to handle metasurface development for other application areas.

  • Magnetosonic Excitation of the Entropy Perturbations in a Plasma with Thermal Conduction Depending on Temperature
    • Anna Perelomova
    2021 Full text Archives of Acoustics

    Nonlinear excitation of the entropy perturbations by magnetosonic waves in a uniform and infinite plasma model is considered. The wave vector of slow or fast mode forms an arbitrary angle (0 B B ) with the equilibrium straight magnetic field, and all perturbations are functions of the time and longitudinal coordinate. Thermal conduction is the only factor which destroys isentropicity of wave perturbations and causes the nonlinear excitation of the entropy mode. A dynamic equation is derived which describes excitation of perturbation in the entropy mode in the field of dominant magnetosonic mode. Effects associatiated with temperature dependent and anisotropic thermal conduction are considered and discussed.

  • Management of Dark Fermentation Broth via Bio Refining and Photo Fermentation
    • Karolina Kucharska
    • Patrycja Makoś-Chełstowska
    • Edyta Słupek
    • Jacek Gębicki
    2021 Full text ENERGIES

    Lignocellulose and starch-based raw materials are often applied in the investigations regarding biohydrogen generation using dark fermentation. Management of the arising post-fermentation broth becomes a problem. The Authors proposed sequential processes, to improve the efficiency of both hydrogen generation and by-products management carried under model conditions. During the proposed procedure, the simple sugars remaining in broth are converted into organic acids, and when these products are used as substrates for the photo fermentation process. To enhance the broth management also conditions promoting Deep Eutectic Solvents (DES) precursors synthesis are simultaneously applied. Application of Box-Behnken design allows defining of the optimal conditions for conversion to DESs precursors. During the procedure hydrogen was obtained, the concentration of hydrogen in the photo fermentation reached up to 819 mL H2/L medium/7 d, depending on the broth type, i.e., when the broth was optimized for formic acid concentration. The DESs precursors were separated and engaged in DESs synthesis. To confirm the formation of the DESs, FT-IR analyses were performed. The Chemical Oxygen Demand of post-fermentation broths after dark fermentation optimized for formic acid was reduced by ca. 82%. The proposed procedure can be successfully used as a method of post-fermentation broth management.

  • Management of Urban Waters with Nature-Based Solutions in Circular Cities—Exemplified through Seven Urban Circularity Challenges
    • Hasan Volkan Oral
    • Matej Radinja
    • Anacleto Rizzo
    • Katharina Kearney
    • Theis Raaschou Andersen
    • Pawel Krzeminski
    • Gianluigi Buttiglieri
    • Derya Ayral-Cinar
    • Joaquim Comas
    • Magdalena Gajewska
    • Marco Hartl
    • David Christian Finger
    • Jan K. Kazak
    • Harri Mattila
    • Patrícia Vieira
    • Patrizia Piro
    • Stefania Anna Palermo
    • Michele Turco
    • Behrouz Pirouz
    • Alexandros Stefanakis
    • Martin Regelsberger
    • Nadia Ursino
    • Pedro Carvalho
    2021 Full text Water

    Nature-Based Solutions (NBS) have been proven to effectively mitigate and solve resource depletion and climate-related challenges in urban areas. The COST (Cooperation in Science and Technology) Action CA17133 entitled “Implementing nature-based solutions (NBS) for building a resourceful circular city” has established seven urban circularity challenges (UCC) that can be addressed effectively with NBS. This paper presents the outcomes of five elucidation workshops with more than 20 European experts from different backgrounds. These international workshops were used to examine the effectiveness of NBS to address UCC and foster NBS implementation towards circular urban water management. A major outcome was the identification of the two most relevant challenges for water resources in urban areas: ‘Restoring and maintaining the water cycle’ (UCC1) and ‘Water and waste treatment, recovery, and reuse’ (UCC2). s Moreover, significant synergies with ‘Nutrient recovery and reuse’, ‘Material recovery and reuse’, ‘Food and biomass production’, ‘Energy efficiency and recovery’, and ‘Building system recovery’ were identified. Additionally, the paper presents real-life case studies to demonstrate how different NBS and supporting units can contribute to the UCC. Finally, a case-based semi-quantitative assessment of the presented NBS was performed. Most notably, this paper identifies the most typically employed NBS that enable processes for UCC1 and UCC2. While current consensus is well established by experts in individual NBS, we presently highlight the potential to address UCC by combining different NBS and synergize enabling processes. This study presents a new paradigm and aims to enhance awareness on the ability of NBS to solve multiple urban circularity issues.

  • Managerial Energy in Sustainable Enterprises: Organizational Wisdom Approach
    • Monika Stelmaszczyk
    • Agata Pierścieniak
    • Anna Krzysztofek
    2021 Full text ENERGIES

    The circular economy (CE) as an idea involves applying the concept of sustainable development that has been gaining worldwide support. This shift in perception of energy and resource-use from its linear to circular forms creates a specific business environment, which constitutes the subject of this research. This article aims to analyze the impact of a manager’s energy on organizational wisdom, focusing on its circular business model activity. In the beginning, the article focuses on presenting ideas of the circular economy, emphasizing the manager’s activity in implementing strategic and operational tasks. These activities are identified as energy to launch mechanisms for developing organizational wisdom for sustainable enterprise. Assuming that organizational wisdom consists of two dimensions, organizational learning, and absorptive capacity, the research identifies relationships between them. The study was conducted at VIVE Textile Recycling Ltd., (Kielce, Poland). Empirical data were collected from 138 managers using the PAPI technique. Regression analysis and structural equation modeling (SEM) were applied to test the research hypotheses. Main results: Managerial energy (ME) is understood as the active attitude of managers who use knowledge from their environments to achieve goals both in the operational and strategic areas. Being an activating force for sustainable enterprise, ME is viewed as the antecedent to the development of enterprises operating in the CE model. ME directly activates the process of developing organizational wisdom in the area of absorptive capacity (AC) at the stages of assimilation, transformation, and exploitation. The transfer of knowledge from the individual to the organizational level (acquisition) requires a mediator, which is in this case the process of organizational learning (OL).

  • Managing change through team building in the context of organizing Erasmus+ mobility projects at the Gdańsk Tech Library
    • Urszula Szybowska
    • Magdalena Stankevic
    2021 Full text Zarządzanie Biblioteką

    The article discusses managing change through team building in the context of organizing Erasmus+ mobility projects in the Gdańsk University of Technology Library as the main strategy which contributed to the projects’ success. The authors describe the projects realized in the years 2017-2019 within the scope of the Erasmus+ programme. The organizers decided to take a responsible and active approach towards managing change and effective team building. Adopting and implementing the strategies according to the process of VMOSA (Vision, Mission, Objectives, Strategies, and Action Plans) turned out to be beneficial and made it possible to implement several successful mobility projects. The authors only mention that there might appear destructive factors which can seriously reduce a team’s effectiveness, highlighting the issue of a person or persons with a narcissistic personality disorder, which seems to be overlooked and underestimated in contemporary cross-disciplinary studies and management practice both in academic libraries and in other types of organizations.