Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst

    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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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.

  • MANDARIN PEEL AS AN AUSPICIOUS FUNCTIONAL FILLER FOR POLYMER COMPOSITES
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Joanna Aniśko
    • Olga Mysiukiewicz
    • Mariusz Marć
    2021 Pełny tekst Macedonian Journal of Chemistry and Chemical Engineering

    This work describes the application of mandarin peel (MP) as a waste filler for high-density polyethylene (HDPE) composites. The main goal was to investigate the impact of the filler's essential oils, which include multiple terpenes and terpenoids, on the processing, physicochemical, mechanical, and thermal properties of the composites as a function of different filler content (1 – 10 wt%), as well as its effect on the color and volatile organic compounds emissions of the composites. At small loadings, MP can be considered an efficient filler for wood-polymer composites, enhancing their flowability, tensile strength, and thermal stability. In addition, it may act as a colorant and aroma compound for polymer materials, and can enhance the thermooxidative resistance of composites. The oxidation induction time was increased from 20 min for HDPE up to 62 min for the composites with 10 wt% filler. The research results demonstrate the application of MP not only in the production of highly-filled composites, but also as an additive that significantly enhances the performance of composites at low concentrations.

  • Manganese–Cobalt Based Spinel Coatings Processed by Electrophoretic Deposition Method: The Influence of Sintering on Degradation Issues of Solid Oxide Cell Oxygen Electrodes at 750 °C
    • Elisa Zanchi
    • Justyna Ignaczak
    • Bartosz Kamecki
    • Piotr Jasiński
    • Sebastian Molin
    • A Boccaccini
    • Federico Smeacetto
    2021 Pełny tekst Materials

    This paper seeks to examine how the Mn–Co spinel interconnect coating microstructure can influence Cr contamination in an oxygen electrode of intermediate temperature solid oxide cells, at an operating temperature of 750 °C. A Mn–Co spinel coating is processed on Crofer 22 APU substrates by electrophoretic deposition, and subsequently sintered, following both the one-step and two-step sintering, in order to obtain significantly different densification levels. The electrochemical characterization is performed on anode-supported cells with an LSCF cathode. The cells were aged prior to the electrochemical characterization in contact with the spinel-coated Crofer 22 APU at 750 °C for 250 h. Current–voltage and impedance spectra of the cells were measured after the exposure with the interconnect. Post-mortem analysis of the interconnect and the cell was carried out, in order to assess the Cr retention capability of coatings with different microstructures.

  • Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 1/2
    • Krzysztof Doerffer
    • Patrycja Bałdowska-Witos
    • Michał Pysz
    • Piotr Doerffer
    • Andrzej Tomporowski
    2021 Pełny tekst Materials

    Wind power plants are considered as ecologically-clean source of energy. However, manufacturing processes cannot be treated that way. Manufacturing processes consume huge amount of electrical and thermal energy and significant amount of materials, e.g. steel, polymers, oils and lubricants. All of the above could be potentially harmful for environment. There are not many works and publications regarding life-cycle analysis of wind power plants. This study objective is to use LCA to the manufacturing and utilization of a specific drag force driven wind turbine. The discussed innovative wind turbine is of the type which assures safety for prosumer application. Drag force driven turbines become more heavy than other types of lift driven turbines but in the same time their characteristic provides opportunity to use easily recyclable materials instead of materials like plastics or composites. The wider look through LCA tools, may change the perspective of view at that type of wind turbines.. Analyzed turbine has capacity of 15 kW and is located in Poland. LCA was carried out using Eco-indicator 99 method in eleven impact categories. Among all of the turbine components the highest negative impact was noted in the case of the tower. Wind turbine under consideration is characterized by high recycling potential. According to presented research recycling provides around 30% reduction of environmental impact.

  • Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 2/2
    • Patrycja Bałdowska-Witos
    • Krzysztof Doerffer
    • Michał Pysz
    • Piotr Doerffer
    • Andrzej Tomporowski
    • Marek Opielak
    2021 Pełny tekst Materials

    The process of conversion of wind kinetic energy into electricity in innovative wind power plant emits practically no harmful substances into the environment. However, the production stage of its components requires a lot of energy and materials. The biggest problem during production plan-ning process of an innovative wind power plant is selection of materials and technologies and, consequently, the waste generated at this stage. Therefore, the aim of this publication was to conduct an environmental analysis of the life cycle of elements of a wind turbine by means of life cycle assessment (LCA) method. The object of the research was a wind power plant divided into five sets of components (tower, turbine structure, rotors, generators, and instrumentation), made mainly of steel and small amounts of polymer materials. Eco-indicator 99 was used as an analytical procedure. The impact of the subjects of analysis on human health, ecosystem quality and re-sources was assessed. Among the analyzed components, the highest level of negative impact on the environment was characterized by the life cycle of the wind turbine tower. The application of recycling processes is reducing the negative impact on the environment in the perspective of the entire life cycle of all studied elements of the wind power plant construction.

  • Mapping negative unintended consequences of disruptive technologies use in smart cities
    • Nina Rizun
    • Magdalena Ciesielska
    • Gabriela Viale Pereira
    • Charalampos Harris Alexopoulos
    2021

    Smart cities governance (SCG) consists of both to foster technology-enabled innovation, and to utilize disruptive technologies (DT) outcomes and impacts to increase public value of urban services. Despite widespread discussion of DT benefits, scientific literature identifies multiple determinants of unintended negative consequences (UC) of DT deployment in smart city initiatives. By considering UC as the negative aspects resulting from underestimating or ignoring the scale of such consequences, this study analyses the objectives of SCG and the negative unintended effects of five selected DT initiatives on these objectives’ implementation. The main contribution of this paper is the identification of determinants of negative UC of Smart City disruptive technologies initiatives and identifying the structure of their impact on the SCG objectives. The results indicate the need to establish a new governance framework of UC in smart cities as a tool to support local governments dealing with the changes caused by DT use in the smart city ecosystem

  • Mapping of the Covid-19 Vaccine Uptake Determinants From Mining Twitter Data
    • Anna Baj-Rogowska
    2021 Pełny tekst IEEE Access

    Opinion polls on vaccine uptake clearly show that Covid-19 vaccine hesitancy is increasing worldwide. Thus, reaching herd immunity not only depends on the efficacy of the vaccine itself, but also on overcoming this hesitancy of uptake in the population. In this study, we revealed the determinants regarding vaccination directly from people’s opinions on Twitter, based on the framework of the 6As taxonomy. Covid-19 vaccine acceptance depends mostly on the characteristics of new vaccines (i.e. their safety, side effects, effectiveness, etc.), and the national vaccination strategy (i.e. immunization schedules, quantities of vaccination points and their localization, etc.), which should focus on increasing citizens' awareness, among various other factors. The results of this study point to areas for potentially improving mass campaigns of Covid-19 immunization to increase vaccine uptake and its coverage and also provide insight into possible directions of future research.

  • Marian Żerebecki – saper, inżynier, wykładowca Politechniki Gdańskiej – mało znany, ale czy zapomniany?
    • Witold Parteka
    2021 Pismo PG

    Artykuł przedstawia sylwetkę Mariana Żerebeckiego – sapera, inżyniera, wykładowcy Politechniki Gdańskiej

  • Marine and Cosmic Inspirations for AI Algorithms
    • Marek Galewski
    • Piotr Duba
    2021 Pełny tekst Per mare ad astra

    Artificial Intelligence (AI) is a scientific area that currently sees an enormous growth. Various new algorithms and methods are developed and many of them meets practical, successful applications. Authors of new algorithms draw different inspirations. Probably the most common one is the nature. For example, Artificial Neural Networks were inspired by the structure of human brain and nervous system while the classic Genetic Algorithm was inspired by the biological evolution process. One of the important areas of AI algorithms applications are optimization problems which can be encountered in practically all fields of science, technology, and everyday life. Amongst AI algorithms used to solve optimization problems, especially large, and still broadening group are swarm intelligence algorithms. They are nature-inspired, meta-heuristic algorithms which usually solve optimization problems by mimicking biological or physical phenomena. They are based mainly on observations of behaviours of various species of animals for example birds , ants , grasshoppers , bees , bats , wolves , fish , dolphins and many other or implement physics laws or environmental phenomena like laws of gravity , motion of galaxies , lightning formation , hydrologic cycle , water evaporation , etc. The general advantages of swarm optimization are: simplicity, easy implementation and the lack of the objective function gradient information requirement. They are usually fast converging and can bypass local optima. Despite large number of algorithms there is no one, ultimate algorithm that solves all types of problems (single- and multi-objective, uni- and multi-modal, with and without boundaries, etc.). Thus, there is a permanent need for more algorithms with new, original inspirations. The paper presents general advantages of swarm intelligence algorithms and a short review of selected, interesting optimization algorithms that draw inspirations from marine nature and cosmic space. These are Gravitational Search Algorithm, Artificial Fish Swarm Optimization, Krill Herd, Whale Optimization Algorithm and Salp Swarm Algorithm

  • Marine Fuel Sulphur Limit Impact on Air Pollution
    • Dominik Kreft
    2021 International Journal of Ecology and Development

    The article presents calculation of Sulphur oxides percentage drop rate in marine industry recorded after 01.01.2020 when new limits, provided by International Maritime Organizations legislation, became effective. Ships’ SOx global emission was estimated and compared between 4th quarter 2019 and 1st quarter 2020. For more accurate estimation 3 seaside cities with big harbors were selected for statistical analysis. Noticeable SOx decrease was observed. In one case the drop was at similar level to theoretical. There were found significant correlations between heavy fuel oil bunker and SOx level in the air.

  • Massively parallel linear-scaling Hartree–Fock exchange and hybrid exchange–correlation functionals with plane wave basis set accuracy
    • Jacek Dziedzic
    • James C. Womack
    • Rozh Ali
    • Chris-Kriton Skylaris
    2021 Pełny tekst JOURNAL OF CHEMICAL PHYSICS

    We extend our linear-scaling approach for the calculation of Hartree–Fock exchange energy using localized in situ optimized orbitals [Dziedzic et al., J. Chem. Phys. 139, 214103 (2013)] to leverage massive parallelism. Our approach has been implemented in the ONETEP (Order-N Electronic Total Energy Package) density functional theory framework, which employs a basis of non-orthogonal generalized Wannier functions (NGWFs) to achieve linear scaling with system size while retaining controllable near-complete-basis-set accuracy. For the calculation of Hartree–Fock exchange, we use a resolution-of-identity approach, where an auxiliary basis set of truncated spherical waves is used to fit products of NGWFs. The fact that the electrostatic potential of spherical waves (SWs) is known analytically, combined with the use of a distance-based cutoff for exchange interactions, leads to a calculation cost that scales linearly with the system size. Our new implementation, which we describe in detail, combines distributed memory parallelism (using the message passing interface) with shared memory parallelism (OpenMP threads) to efficiently utilize numbers of central processing unit cores comparable to, or exceeding, the number of atoms in the system. We show how the use of multiple time-memory trade-offs substantially increases performance, enabling our approach to achieve superlinear strong parallel scaling in many cases and excellent, although sublinear, parallel scaling otherwise. We demonstrate that in scenarios with low available memory, which preclude or limit the use of time-memory trade-offs, the performance degradation of our algorithm is graceful. We show that, crucially, linear scaling with system size is maintained in all cases. We demonstrate the practicability of our approach by performing a set of fully converged production calculations with a hybrid functional on large imogolite nanotubes up to over 1400 atoms. We finish with a brief study of how the employed approximations (exchange cutoff and the quality of the SW basis) affect the calculation walltime and the accuracy of the obtained results.

  • Matematyka na zajęciach z arkuszy kalkulacyjnych
    • Agnieszka Bartłomiejczyk
    • Dawid Ptach
    • Marcin Wata
    2021 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Na zajęciach, zarówno w szkole, jak i na uczelni, do pokazania technicznej strony użycia arkusza kalkulacyjnego, tj.dostępnych funkcjonalności oraz organizacji danych, często wykorzystuje się proste zadania matematyczne. W naszym artykule zwracamy uwagę na potrzebę rozumienia przez użytkowników arkuszy kalkulacyjnych pojęć matematycznych, które umożliwiają odpowiednie przygotowanie danych oraz zinterpretowanie uzyskanych za pomocą narzędzi arkusza wyników. Zajęcia z Technologii informacyjnych, Arkuszy kalkulacyjnych czy z Zarządzania projektami są okazją do pokazania wagi interdyscyplinarności w nauce, w tym do motywowania, głębszego poznania i zrozumienia matematyki.

  • Materiały sorpcyjne wykorzystywane w maskach ochronnych
    • Paulina Nowicka
    • Marta Orciuch
    • Sandra Orylska
    • Sandra Rosa
    • Dominika Sołtyszewska
    • Natalia Łukasik
    2021 Pełny tekst Analityka: Nauka i Praktyka

    Od zarania dziejów ludzie starają się chronić przed chorobami zakaźnymi, stosując środki ochrony osobistej, do których należą maski ochronne. Z uwagi na obecnie panującą pandemię wirusa SARS-CoV-2, noszenie masek stało się normą w walce z koronawirusem. Jednak zagrożenia dla górnych dróg oddechowych nie stanowią wyłącznie wirusy, lecz również cząstki stałe zawieszone w powietrzu. Szczególnie w krajach wysoko uprzemysłowionych, narażenie na duże stężenie pyłów może przyczynić się nawet do śmierci, gdy dostaną się one do krwioobiegu. Z tego względu, noszenie masek może znacząco poprawić jakość zdrowia i życia. W tym artykule scharakteryzowano dostępne filtry w maskach ochronnych, do których należą membrany z nanowłókien polimerowych, filtry na bazie węgla aktywnego oraz filtry na bazie struktur metaloorganicznych (MOF). Przedstawiono także nowe rozwiązania, takie jak maski na bazie antybakteryjnych materiałów, które mają uskutecznić ochronę przed patogenami.

  • Mathematical approach to design 3D scaffolds for the 3D printable bone implant
    • Wiktoria Wojnicz
    • Marek Augustyniak
    • Piotr Borzyszkowski
    2021 Pełny tekst Biocybernetics and Biomedical Engineering

    This work demonstrates that an artificial scaffold structure can be designed to exhibit mechanical properties close to the ones of real bone tissue, thus highly reducing the stress-shielding phenomenon. In this study the scan of lumbar vertebra fragment was reproduced to create a numerical 3D model (this model was called the reference bone sample). New nine 3D scaffold samples were designed and their numerical models were created. Using the finite element analysis, a static compression test was performed to assess the effective Young modulus of each tested sample. Also, two important metrics of each sample were assessed: relative density and surface area. Each new designed 3D scaffold sample was analyzed by considering two types of material properties: metal alloy properties (Ti-6Al-4V) and ABS polymer properties. Numerical analysis results of this study confirm that 3D scaffold used to design a periodic structure, either based on interconnected beams (A, B, C, D, E and F units) or made by removing regular shapes from base solid cubes (G, H, I units), can be refined to obtain mechanical properties similar to the ones of trabecular bone tissue. Experimental validation was performed on seven scaffolds (A, B, C, D, E, F and H units) printed from ABS material without any support materials by using Fused Deposition Modeling (FMD) technology. Results of experimental Young modulus of each printed scaffold are also presented and discussed.

  • Mathematical model of the energy consumption calculation during the pine sawn wood (Pinus sylvestris L.) drying process
    • Aleksandra Konopka
    • Jacek Barański
    • Kazimierz Orłowski
    • Dariusz Mikielewicz
    • Ladislav Dzurenda
    2021 Pełny tekst WOOD SCIENCE AND TECHNOLOGY

    The article presents the modification of the existing mathematical model to calculate energy consumption during conventional drying process. Apart from energy consumption the model permits to estimate the time of high-temperature drying process. The drying medium is air and superheated steam mixture. The obtained calculation results were compared with conducted experimental tests of drying square-edged sawn sapwood timber (Pinus sylvestris L.). The pine sawn wood samples were dried according to three different drying modes, namely mild, normal and intense. The experiments were performed in a semi-industrial scale drying chamber. On the basis of the experimental research available, existing mathematical models of drying wood have been improved. The developed model included the following changes: a different drying time for each mode and type of drying medium (moisturized air or air and superheated steam mixture). The use of an intensive drying mode significantly reduced the drying process time. The developed mathematical model revealed that the energy consumption of the drying process increases with the intensity of the mode used.