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Politechniki Gdańskiej

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  • Towards Scalable Simulation of Federated Learning
    • Tomasz Kołodziej
    • Paweł Rościszewski
    2021 Communications in Computer and Information Science

    Federated learning (FL) allows to train models on decentralized data while maintaining data privacy, which unlocks the availability of large and diverse datasets for many practical applications. The ongoing development of aggregation algorithms, distribution architectures and software implementations aims for enabling federated setups employing thousands of distributed devices, selected from millions. Since the availability of such computing infrastructure is a big barrier to experimenting with new approaches, we claim that efficient simulation of FL is necessary and propose the PaSSiFLora library for simulating FL clients in a cluster environment. In PaSSiFLora, the training algorithm is actually performed on real data, but each cluster node can simulate multiple FL clients. Because uniform random selection of clients results in poor simulation performance due to load imbalance, we propose to use uniform random selection of MultiClients. Each MultiClient runs on a single cluster node and in each training iteration is responsible for simulating several clients, selected from a set of local clients. Our experimental results based on the FEMNIST dataset show that PaSSiFLora is capable of simulating 1536 clients and has a good scalability on 48 cluster nodes, which reduces the average iteration time to 13.57 s, from 330.61 s in the case of one cluster node. The MultiClient architecture allows to improve the average performance by up to 75% while it does not cause significant differences in model accuracy during the training. Additionally, correctness of the training is verified against existing FL frameworks: LEAF and TFF.

  • Towards Understanding the Health Aspects of the Processing of Lignocellulosic Fillers
    • Aleksander Hejna
    • Mariusz Marć
    2021 Pełny tekst Proceedings

    Health and safety issues should be addressed during the development and investigation of the industrial processes. In order to develop a sustainable process and fully evaluate its benefits and drawbacks for its optimization, it is crucial to determine its impact on the surrounding environment. This study aimed to assess the emission of volatile organic compounds during the modification of lignocellulosic fillers with passive dosimetry. Two types of processes were investigated: diisocyanate treatment of commercial lignocellulosic fillers in a batch mixer and thermo-mechanical treatment of brewers’ spent grain using a twin-screw extruder. The presence of multiple terpenes and terpenoids was detected during the processing of fillers. The main compounds detected during modification were camphene, 3-carene, limonene, α-pinene, and cymenes. These compounds can show the irritating and allergic character, according to the Globally Harmonized System of Classification and Labelling of Chemicals, as well as NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response. Some of them are also characterized by relatively low values of flash point, even below 40 °C. Therefore, their emissions during the modification of cellulose materials should be carefully monitored, and proper precautions need to be taken.

  • Towards Use of OntoClean for Ontology Contextualization
    • Wojciech Waloszek
    2021 Pełny tekst Procedia Computer Science

    Ontologies are formal systems of concepts used to describe numerous domains of interest. Ontologies are usually very expressive, but it comes at a price of computationally expensive reasoning over them. In our previous work we discussed the possible performance benefits that can be obtained by decomposing an ontology into contexts. While the benefits are appealing, we discovered that, in our case, the main obstacle against using contextual versions of ontologies was the necessity of performing the costly process of their decomposition with the participation of human experts. In this paper we discuss the possibility of using OntoClean method for streamlining and at least partial automation of suggesting a decomposition of an ontology into contexts. We present a hypothesis about how to build a structure of contexts, and verify this hypothesis against several ontologies used in state-of-the-art research. The ontologies have been obtained by us in the process that uses elements of Systematic Literature Review. The final assessment of the method has been performed by human experts, during interviews, and we present the details of their evaluation in the paper.

  • Toxinas de setas
    • Roman Kotłowski
    2021

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  • Trace Metal Contamination of Bottom Sediments: A Review of Assessment Measures and Geochemical Background Determination Methods
    • Nicole Nawrot
    • Ewa Wojciechowska
    • Muhammad Mohsin
    • Suvi Kuittinen
    • Ari Pappinen
    • Shahabaldin Rezania
    2021 Pełny tekst Minerals

    This paper provides an overview of different methods of assessing the trace metal (TM) contamination status of sediments affected by anthropogenic interference. The geochemical background determination methods are also described. A total of 25 papers covering rivers, lakes, and retention tanks sediments in areas subjected to anthropogenic pressure from the last three years (2019, 2020, and 2021) were analysed to support our examination of the assessment measures. Geochemical and ecotoxicological classifications are presented that may prove useful for sediment evaluation. Among the geochemical indices, several individual pollution indices (CF, Igeo, EF, Pi (SPI), PTT), complex pollution indices (PLI, Cdeg, mCdeg, Pisum, PIAvg, PIaAvg, PIN, PIProd, PIapProd, PIvectorM, PINemerow, IntPI, MPI), and geochemical classifications are compared. The ecotoxicological assessment includes an overview of Sediment Quality Guidelines (SQG) and classifications introduced nationally (as LAWA or modified LAWA). The ecotoxicological indices presented in this review cover individual (ERi) and complex indices (CSI, SPI, RAC, PERI, MERMQ). Biomonitoring of contaminated sites based on plant bioindicators is extensively explored as an indirect method for evaluating pollution sites. The most commonly used indices in the reviewed papers were Igeo, EF, and CF. Many authors referred to ecotoxicological assessment via SQG. Moreover, PERI, which includes the toxic response index, was just as popular. The most recognised bioindicators include the Phragmites and Salix species. Phragmites can be considered for Fe, Cu, Cd, and Ni bioindication in sites, while Salix hybrid cultivars such as Klara may be considered for phytostabilisation and rhizofiltration due to higher Cu, Zn, and Ni accumulation in roots. Vetiveria zizanoides demonstrated resistance to As stress and feasibility for the remediation of As. Moreover, bioindicators offer a feasible tool for recovering valuable elements for the development of a circular economy (e.g., rare earth elements).

  • Tracking Fluorescent Dye Dispersion from an Unmanned Aerial Vehicle
    • Paweł Burdziakowski
    • Piotr Zima
    • Paweł Wielgat
    • Dominika Kalinowska
    2021 Pełny tekst SENSORS

    Commercial unmanned aerial vehicles continue to gain popularity and their use for collecting image data and recording new phenomena is becoming more frequent. This study presents an effective method for measuring the concentration of fluorescent dyes (fluorescein and Rhodamine WT) for the purpose of providing a mathematical dispersion model. Image data obtained using a typical visible-light camera was used to measure the concentration of the dye floating on water. The reference measurement was taken using a laboratory fluorometer. The article presents the details of three extensive measurement sessions and presents elements of a newly developed method for measuring fluorescent tracer concentrations. The said method provides tracer concentration maps presented on the example of an orthophoto within a 2 × 2 m discrete grid.

  • Transcriptomic landscape of blood platelets in healthy donors
    • Anna Supernat
    • Marta Popęda
    • Krzysztof Pastuszak
    • Myron G Best
    • Peter Gresner
    • Sjors In ‘t Veld
    • Bartłomiej Siek
    • Natalia Bednarz-Knoll
    • Matthew T. Rondina
    • Tomasz Stokowy
    • Thomas Würdinger
    • Jacek Jassem
    • Anna Żaczek
    2021 Pełny tekst Scientific Reports

    BACKGROUND Blood platelet RNA-sequencing is increasingly used among the scientific community. Aberrant platelet transcriptome is common in cancer or cardiovascular disease, but reference data on platelet RNA content in healthy individuals are scarce and merit complex investigation. METHODS We sought to explore the dynamics of platelet transcriptome. Datasets from 204 healthy donors were used for the analysis of splice variants, particularly with regard to age, sex, blood storage time, unit of collection or library size. RESULTS Genes B2M, PPBP, TMSB4X, ACTB, FTL, CLU, PF4, F13A1, GNAS, SPARC, PTMA, TAGLN2, OAZ1 and OST4 demonstrated the highest expression in the analysed cohort, remaining substantial transcription consistency. CSF3R gene was found upregulated in males (fold change 2.10, FDR q<0.05). Cohort dichotomisation according to the median age, showed upregulated KSR1 in the older donors (fold change 2.11, FDR q<0.05). Unsupervised hierarchical clustering revealed two clusters which were irrespective of age, sex, storage time, collecting unit or library size. However, when donors are analysed globally (as vectors), sex, storage time, library size, the unit of blood collection as well as age impose a certain degree of between- and/or within-group variability. CONCLUSIONS Separately analysed platelet splice variants retain general consistency, with a few interesting deviating genes from these general trends. On the other hand, the multidimensional analysis revealed statistically significant variability between and within the analysed groups. Our work provides a reference for studies working both on healthy platelets and pathological conditions affecting platelet transcriptome.

  • Transformation of polyvinyl chloride (PVC) into a versatile and efficient adsorbent of Cu(II) cations and Cr(VI) anions through hydrothermal treatment and sulfonation
    • Xianbao Xu
    • Daan Zhu
    • Xiaonuan Wang
    • Liling Deng
    • Xinyun Fan
    • Zizhen Ding
    • Ai Zhang
    • Gang Xue
    • Yanbiao Liu
    • Weimin Xuan
    • Xiang Li
    • Jacek Mąkinia
    2021 Pełny tekst JOURNAL OF HAZARDOUS MATERIALS

    The reuse of waste polyvinyl chloride (PVC) has drawn much attention as it can reduce plastic waste and associated pollution, and provide valuable raw materials and products. In this study, sulfonated PVC-derived hydrochar (HS-PVC) was synthesized by two-stage hydrothermal treatment (HT) and sulfonation, and shown to be a versatile adsorbent. The reoval of Cu(II) cations and Cr(VI) anions using HS-PVC reached 81.2 ± 1.6% and 60.3 ± 3.8%, respectively. The first stage of HT was crucial for the dichlorination of PVC and the formation of an aromatic structure. This stage guaranteed the introduction of -SO3H onto PVC-derived hydrochar through subsequent sulfonation. HT intensities (i.e., temperature and time) and sulfonation intensity strongly determined the adsorption capacity of HS-PVC. Competitive adsorption between Cu(II) and Cr(VI) onto HS-PVC was demonstrated by binary and preloading adsorption. The proposed Cu(II) cations adsorption mechanism was electrostatic adsorption, while Cr(VI) were possibly complexed by the phenolic -OH and reduced to Cr(III) cations by C=C groups in HS-PVC. In addition, HS-PVC derived from PVC waste pipes performed better than PVC powder for Cu(II) and Cr(VI) removal (＞90%). This study provides an efficient method for recycling waste PVC and production of efficient adsorbents.

  • Transformation of the Odesa Waterfront
    • Piotr Lorens
    • Andrii Polishchuk
    2021 Pełny tekst Przestrzeń Ekonomia Społeczeństwo

    Odesa is a unique city: it is the third-largest city in Ukraine and the second in the Black sea region. During its short but eventful history, it gathered a variety of cultural layers within its boundaries, what had reflected in its architecture, urban life, and unique accent of its inhabitants. The city`s waterfront is considered to be the Pearl of the Black Sea. Starting with the receiving of the Porto Franco status in 1819, Odesa was the economic nexus and the symbol of entrepreneurship in the Russian Empire. During the Soviet period, city and port expanded to reach the goals of the communist era. The paradigm shift in economic realms related to the transformation of the economy at the beginning of the 1990s shed light on the city's weaknesses. Water and air pollution, large industrial zones in the sea façade of the city, and lack of high-level infrastructure for tourists had transformed the image of Odesa into a regular post-soviet town in the conditions of the market economy. On the other hand, the newborn post-soviet and postindustrial citizens of Odesa have different priorities and do not necessarily think about the spatial problems. A comprehensive study, using the observations, literature review, and interviews, was conducted to describe the influence of the social realm on an urban form of the Waterfront. The result of the analysis supports the hypothesis of the study: the trajectories of the social, economic, and spatial development of the Odesa waterfront are not correlating with each other. Within this paper the possible scenarios and prospects for transformation of the urban waterfront of Odesa are discussed on the basis of the wider perspective of reshaping the post-soviet waterfronts

  • Transforming a Traditional, Family-Run Car Dealership into a Digital-Era Modern Service Provider
    • Sławomir Ostrowski
    2021 Pełny tekst

    The automotive industry today faces multiple challenges. The automotive market is characterised by frequent changes and technological developments in comfort and safety of travel by all types of vehicles. The division between traditional and modern services is related to their susceptibility to technological progress. We should differentiate between two types of technology: technology used directly in vehicles and technology utilized in the delivery of products and services, which is transforming today’s automotive sales. It is the technological sphere that has contributed to numerous changes, the cumulative effect of which affects the perception of services as ‘modern’. Nowadays, customers expect a modern approach to sales, including the possibility of transferring the car sales process to the Internet, a virtual world in which, in the 21st century, state-of-the-art, immediately accessible solutions are expected. It is thus necessary to move traditional automotive sales online (always accessible location) in order to create a more convenient way of buying a car, regardless of restrictions such as those that emerged due to the outbreak of pandemic. This article presents a pilot study conducted in a family business specialising in the sale of new and second-hand cars. The study revealed a need to change car sales processes over the next few years and introduce modern automotive services. Purchasing a new or second-hand vehicle online no longer seems like a distant future.

  • Transparency of publicly available information about fiscal and monetary policy in Poland
    • Maria Jastrzębska
    2021 Pełny tekst

    Research background: The quality of information provided by fiscal and monetary authorities are important in a democratic state. Ensuring fiscal policy transparency reduces fiscal risk and corruption and promotes public acceptance of fiscal reforms. Ensuring transparency in monetary policy allows market participants to anticipate central bank responses and take their effects into account when making investment and consumption decisions. Aim of the article: The aim of the article is to evaluate the transparency of information provided to the public by the fiscal and monetary authorities in Poland in the light of international standards of fiscal and monetary policy transparency and to propose changes to increase it. Methods: Qualitative analysis, deductive and inductive reasoning were used. The assessment of the level of transparency of publicly available information on fiscal and monetary policy in Poland was based on the analysis of the implementation of good practices formulated by the International Monetary Fund and the open budget index calculated by the International Budget Partnership. Findings and added value: There are no publications in the national literature dealing with the transparency of publicly available information on fiscal and monetary policies in the context of coordination of these policies. Poland lacks transparent message about public finance, with particular emphasis on the state budget, which would allow citizens to control the government's fiscal policy actions. There is a lack of transparent information about the operations of the NBP in relation to the government. There is a lack of clear, reliable and complete information for citizens about the coordination of actions taken by the fiscal and monetary authorities in Poland to achieve specific objectives of the state's financial policy.

  • Trends shaping innovations in the aerosol market
    • Norbert Piotrowski
    2021 Pełny tekst World Aerosols. The Voice of the Aerosol Industry

    New hygiene regimes and sustainability commitments are helping to shape the aerosol market. Norbert Piotrowski of Aerosol Service Poland explains the thinking behind the company’s latest hygiene innovations.

  • Triazoloacridone C-1305 impairs XBP1 splicing by acting as a potential IRE1α endoribonuclease inhibitor
    • Sylwia Bartoszewska
    • Jarosław Króliczewski
    • David Crossman
    • Aneta Pogorzelska
    • Maciej Bagiński
    • James F. Collawn
    • Rafal Bartoszewski
    2021 Pełny tekst CELLULAR & MOLECULAR BIOLOGY LETTERS

    Inositol requiring enzyme 1 alpha (IRE1α) is one of three signaling sensors in the unfolding protein response (UPR) that alleviates endoplasmic reticulum (ER) stress in cells and functions to promote cell survival. During conditions of irrevocable stress, proapoptotic gene expression is induced to promote cell death. One of the three signaling stressors, IRE1α is an serine/threonine-protein kinase/endoribonuclease (RNase) that promotes nonconventional splicing of XBP1 mRNA that is translated to spliced XBP1 (XBP1s), an active prosurvival transcription factor. Interestingly, elevated IRE1α and XBP1s are both associated with poor cancer survival and drug resistance. In this study, we used next-generation sequencing analyses to demonstrate that triazoloacridone C-1305, a microtubule stabilizing agent that also has topoisomerase II inhibitory activity, dramatically decreases XBP1s mRNA levels and protein production during ER stress conditions, suggesting that C-1305 does this by decreasing IRE1α’s endonuclease activity.

  • Tripping of F-type RCDs for high-frequency residual currents
    • Hanan Tariq
    • Stanisław Czapp
    2021

    Residual current devices (RCDs) are apparatus commonly used for protection against electric shock in low-voltage electrical installations. They protect people in the case of an earth fault or even in the case of direct contact with the live parts. However, to be effective protective devices, RCDs have to detect residual currents of various waveform shapes which appear in modern electrical installations. For this purpose, RCDs are classified into four types: AC; A; F and B. This paper is focused on F-type RCDs provided for the detection, in particular, of mixed-frequency residual currents. According to the standard referring to the F-type RCDs, they are tested by manufacturers under the non-sinusoidal waveform having components generated by control equipment supplied from a single-phase. In this paper, results of two tripping tests (other than normative) of F-type RCDs are presented. During the first test, waveforms having components generated by control equipment supplied from three phases were forced. During the second test, high-frequency pure sinusoidal residual currents were generated. Results of these tests have shown that F-type RCDs may detect mixed-frequency residual currents other than the normative but may not react to sinusoidal currents of frequencies higher than 1 kHz.

  • Tunable Dielectric Switching of (Quinuclidinium)[MnCl4] Hybrid Compounds
    • Natalia Wójcik
    • Dorota A. Kowalska
    • Monika Trzebiatowska
    • Ewelina Jach
    • Adam Ostrowski
    • Waldemar Bednarski
    • Marek Gusowski
    • Piotr Staniorowski
    • Agnieszka Ciżman
    2021 Pełny tekst Journal of Physical Chemistry C

    Inorganic−organic hybrid QMnCl (Q = quinuclidinium) crystals were synthesized and characterized. The X-ray and variable-temperature IR/Raman analysis demonstrate that the crystals undergo a reversible structural phase transition, which originates from an order−disorder process and is related to the dynamics of the organic Q cation. Dielectric function measurements disclose a switchability between low (“OFF”) and high (“ON”) dielectric states centered at around 285 K. Owing to a remarkable temperature-dependent dielectric function, this type of molecular compound can represent an interesting tunable and switchable dielectric material for a diverse range of applications.

  • Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
    • Artur Piróg
    • Francesca Cantini
    • Łukasz Nierzwicki
    • Igor Obuchowski
    • Bartłomiej Tomiczek
    • Jacek Czub
    • Krzysztof Liberek
    2021 Pełny tekst JOURNAL OF MOLECULAR BIOLOGY

    Small heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as a consequence of ibpA gene duplication event, a two-protein sHsp (IbpA and IbpB) system has evolved. IbpA and IbpB are functionally divergent. Purified IbpA, but not IbpB, stably interacts with aggregated substrates, yet both sHsps are required to be present at the substrate denaturation step for subsequent efficient Hsp70-Hsp100-dependent substrate refolding. IbpA and IbpB interact with each other, influence each other’s expression levels and degradation rates. However, the crucial information on how these two sHsps interact and what is the basic building block required for proper sHsps functioning was missing. Here, based on NMR, mass spectrometry and crosslinking studies, we show that IbpA-IbpB heterodimer is a dominating functional unit of the two sHsp system in Enterobacterales. The principle of heterodimer formation is similar to one described for homodimers of single bacterial sHsps. β-hairpins formed by strands β5 and β7 of IbpA or IbpB crystallin domains associate with the other one's β-sandwich in the heterodimer structure. Relying on crosslinking and molecular dynamics studies, we also propose the orientation of two IbpA-IbpB heterodimers in a higher order tetrameric structure.

  • Two complementary approaches for the synthesis and isolation of stable phosphanylphosphaalkenes
    • Aleksandra Ziółkowska
    • Natalia Szynkiewicz
    • Łukasz Ponikiewski
    2021 Pełny tekst Inorganic Chemistry Frontiers

    Phospha-Wittig (phosphanylphosphinidene titanium(IV) complex) and phospha-Peterson (lithiated diphosphane) reactions were used to obtain phosphanylphosphaalkenes with the general formula XYC=P-PtBu2 (X = alkyl, aryl group or H; Y = alkyl or aryl group). Therefore, two series of reactions with different ketones and aldehydes were performed. An examination revealed that the two methods are complementary. For smaller carbonyl compounds, the phospha-Wittig reaction was shown to be a much better method, while for larger substituents (mainly aromatic), the phospha-Peterson reaction was shown to be a reliable method. These studies led to, among other things, the isolation of seven phosphanylphosphaalkenes in crystalline form after the phospha-Peterson reaction: (Ph)2C=P-PtBu2 (3a), Z-(Ph)(4-CN-Ph)C=P-PtBu2 (3c), (4-CN-Ph)2C=P-PtBu2 (3d), (4-MeO-Ph)2C=P-PtBu2 (3e), E-tBu(Ph)C=P-PtBu2 (3f), E-{(Me)2N-Ph}(H)C=P-PtBu2 (4d) and E-PhPh(H)C=P-PtBu2 (4e). Corresponding compounds were obtained at high yields under mild conditions, and more importantly, these new species are relatively air- and absolutely moisture-stable, especially these originating from aldehydes aldehyde. Additionally, a comprehensive DFT study helped us to establish not only the key factors crucial for the effective phospha-Wittig-based synthesis of C=P-P species but also the consecutive steps along the reaction path leading to the formation of these compounds.

  • Two-photon microperimetry with picosecond pulses
    • Marcin Marzejon
    • Łukasz Kornaszewski
    • Jakub Bogusławski
    • Piotr Ciąćka
    • Miłosz Martynow
    • Grażyna Palczewska
    • Sebastian Maćkowski
    • Krzysztof Palczewski
    • Maciej Wojtkowski
    • Katarzyna Komar
    2021 Pełny tekst Biomedical Optics Express

    Two-photon vision is a phenomenon associated with the perception of short pulsesof near-infrared radiation (900-1200 nm) as a visible light. It is caused by the nonlinear processof two-photon absorption by visual pigments. Here we present results showing the influence ofpulse duration and repetition rate of short pulsed lasers on the visual threshold. We comparedtwo-photon sensitivity maps of the retina obtained for subjects with normal vision using acost-effective fiber laser (λc=1028.4 nm,τp=12.2 ps,Frep=19.17 MHz) and a solid-state laser(λc=1043.3 nm,τp=0.253 ps,Frep=62.65 MHz). We have shown that in accordance with thedescription of two-photon absorption, the average optical power required for two-photon visionfor a fiber laser is 4 times greater than that for a solid-state laser. Mean sensitivity measured forthe first one is 5.9±2.8 dB lower than for the second but still 17 dB away from the safety limit,confirming that picosecond light sources can be successfully applied in microperimetry. Thisdevelopment would dramatically reduce the cost and complexity of future clinical devices

  • Two-Row ESPAR Antenna with Simple Elevation and Azimuth Beam Switching
    • Mateusz Rzymowski
    • Łukasz Kulas
    2021 Pełny tekst IEEE Antennas and Wireless Propagation Letters

    In this letter, we propose a two-row electronically steerable parasitic array radiator (ESPAR) antenna designed for direction of arrival (DoA) estimation in Internet of Things (IoT) applications relying on simple microcontrollers. The antenna is capable of elevation and azimuth beam switching using a simple microcontroller-oriented steering circuit and provides 18 directional radiation patterns, which can be grouped in 3 distinctive sets having different directions in the elevation. For each elevation direction, there are 6 different beam configurations that cover 360 degrees in the horizontal plane. Measurements of the realized antenna prototype carried out in an anechoic chamber show good agreement with numerical simulations. The antenna prototype provides low side lobe level (SLL), low half power beam width (HPBW) in both elevation and horizontal directions, and exhibit monotonous drop from the maximum value for all 18 radiation patterns. Therefore, the antenna is a good candidate for IoT nodes capable of DoA estimation in situations when radio frequency (RF) signals are impinging the antenna from different directions in elevation.

  • Two-step synthesis of niobium doped Na–Ca–(Mg)–P–Si–O glasses
    • Natalia Wójcik
    • S Ali
    • Aleksandra Mielewczyk-Gryń
    • B Jonson
    2021 Pełny tekst JOURNAL OF MATERIALS SCIENCE

    Niobium doped biosolubility glasses in the Na–Ca–(Mg)–P–Si–O system were prepared by using an untypical two-step synthesis route. The parent glass was melted in air atmosphere at 1350 °C followed by re-melting the glass in Nb crucible with the addition of metallic Mg/Ca powder in the nitrogen atmosphere. The second melting step was carried out at 1450–1650 °C, using an induction furnace. The topography and structure of the obtained glasses were characterized by confocal microscopy, X-ray powder diffraction and infrared spectroscopic techniques. The chemical compositions were examined by energy-dispersive X-ray spectroscopy (EDS). The glasses were found to be of grayish color, X-ray amorphous and having network connectivity between * 2.5 and 2.7. The network connectivity of re-melted glasses was lower than the one of the parent glass. The glass structure consists of a highly disrupted silicate network of predominantly Q2 groups as well as isolated orthophosphate tetrahedra. The parent glass contains nanocrystallites consisted of apatitic PO43- groups. The re-melted glasses contain nonapatitic or amorphous calcium phosphates. The obtained glass transition temperatures range from 530 to 568 °C and exhibit higher values for glassed doped with Ca metal. These glasses have improved thermal stability as compared to reference bioglasses. The biosolubility test in phosphate buffered saline solution (PBS) confirms that the glasses have biosolubility properties and HAp formation on the surfaces was observed

  • Twórczość - przekraczanie dyscyplin. Analiza postawy autorskiej
    • Agnieszka Kurkowska
    2021 Pełny tekst Facta Ficta. Journal of Theory, Narrative & Media

    Agnieszka Kurkowska w artykule Twórczość - przekraczanie dyscyplin. Analiza postawy autorskiej odnosi się do zagadnienia poruszania w różnych obszarach wiedzy i umiejętności przez jednostkowego twórcę. Zarysowany jest problem niemożności wąskiego traktowania architektury jako dziedziny stricte inżynieryjnej. Architekt otwarty na otaczające problemy przestrzenne, ich fizyczne i pozafizyczne aspekty sięga w swoich wypowiedziach do obszarów pokrewnych architekturze, aby swoją wypowiedź wzmocnić i wzbogacić. W poniższej pracy podjęto próbę udowodnienia tezy, że przeanalizowana tu postawa autorska ukazuje konieczność przekraczania dyscyplin w projektowaniu architektonicznym. Ukazano, w oparciu o studium przypadku, w jaki sposób poruszanie się poza ścisła inżynierią może wzbogacać projekty architekta i wzmacniać możliwość ich oddziaływania. Na dobrane do prezentowanej analizy projekty składają się projekty obiektów architektonicznych, projekty małej architektury, mebli, przedmiotów użytkowych, wnętrz. To również projekty artystyczne posiłkujące się malarstwem, grafiką, rzeźbą, fotografią czy instalacją przestrzenną, także publikacje książkowe. Kolejną kategorią są projekty edukacyjne skoncentrowane na cyklach działań warsztatowych, materiałach edukacyjnych, wydarzeniach partycypacyjnych. Wszystkie przykłady łączy osoba autora, poruszającego się w swojej pracy w obszarze kilku dyscyplin, co w perspektywie czasowej ukazuje kompletną, wieloelementową postawę wobec przestrzeni, korzystających z niej ludzi i wypełniających ją obiektów. Wspomniana postawa zawiera kilka istotnych komponentów, które przeważając w określonych przypadkach, przenoszą go do poszczególnych zadań i związanych z nimi ról społecznych i zawodowych. Bywa więc architekt twórcą, gdy posługuje się narzędziami wyrazu artystycznego, kreując indywidualne, unikalne obiekty w różnej skali, poruszając się jednocześnie w obszarze sztuki i inżynierii. Może też być naukowcem, czy badaczem analizujący, pogłębiający, poszukującym, weryfikujący przyjęte rozwiązania. Czasami staje się pedagogiem czy edukatorem, gdy swoje działania skupia na przekazaniu wiedzy. Ponad wszystko architekt pozostaje jednakże człowiekiem o określonej strukturze psychicznej i fizycznej, będąc osobowym elementem społeczności. Architekt to autor przekraczający różne dyscypliny w ramach swojej twórczości czego konieczności i celowości mają dowieść przedstawione analizy i wspierające je studium przypadku.

  • Type III Responses to Transient Inputs in Hybrid Nonlinear Neuron Models
    • Jonathan E. Rubin
    • Justyna Signerska-Rynkowska
    • Jonathan D. Touboul
    2021 Pełny tekst SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS

    Experimental characterization of neuronal dynamics involves recording both of spontaneous activity patterns and of responses to transient and sustained inputs. While much theoretical attention has been devoted to the spontaneous activity of neurons, less is known about the dynamic mechanisms shaping their responses to transient inputs, although these bear significant physiological relevance. Here, we study responses to transient inputs in a widely used class of neuron models (nonlinear adaptive hybrid models) well-known to reproduce a number of biologically realistic behaviors. We focus on responses to transient inputs that have been previously associated with Type III neurons, arguably the least studied category in Hodgkin's classification, which are those neurons that never exhibit continuous firing in response to sustained excitatory currents. The two phenomena that we study are postinhibitory facilitation, in which an otherwise subthreshold excitatory input can induce a spike if it is applied with proper timing after an inhibitory pulse, and slope detection, in which a neuron spikes to a transient input only when the input's rate of change is in a specific, bounded range. Using dynamical systems theory, we analyze the origin of these phenomena in nonlinear hybrid models. We provide a geometric characterization of dynamical structures associated with postinhibitory facilitation in the system and an analytical study of slope detection for tent inputs. While the necessary and sufficient conditions for these behaviors are easily satisfied in neurons with Type III excitability, our proofs are quite general and valid for neurons that do not exhibit Type III excitability as well. This study therefore provides a framework for the mathematical analysis of these responses to transient inputs associated with Type III neurons in other systems and for advancing our understanding of these systems' computational properties.

  • Typology and comparative analysis of black tents built in tradition of iranian tribes
    • Najmeh Hassas
    2021 Pełny tekst

    This study focused on the habits and way of life of nomads in the Iranian Highlands, but their homes, called Black Tents, were of the main interest. The research explored the construction of the Black Tents and the way of shaping the space in which family life takes place. It concerned the architectural forms of tents, structures and materials from which they are erected, as well as interior furnishings and objects that determine their character. The methods used in the research include descriptive analysis and graphical presentation of the test results. The inquiry was conducted in libraries, archives and institutions and using official websites. The author also conducted drawing and photographic inventories of tents and everyday life of nomads. Laboratory tests of the next phase of work have been documented with printouts and presentations of the sets of devices used in the research. Further analysis was carried out using advanced software computer programmes, such as 3DMax, ABAQUS and other professional civil engineering digital tools allowing to obtain comparable results. The research results and summaries of their individual phases are presented in the form of maps, charts and tables. As a result of macroscopic studies, it turned out that the fabric, made of cloth woven from long black goat hair, with which the structures are covered (Chador), which is woven by women, is the same for all tribes. Women also erect and dismantle tents before and after the journey and so have an influence on their construction. The analysis of the dimensions and forms of the discussed seven types of tents from different parts of the country showed large differences, which is evidence of creativity and engineering thinking. The next step of the research was to check to what extent the stability of each tent is adjusted to the climatic situation in which it is used. For this purpose, models were created in the ABACUS program. Their responses to wind and rain loads have been studied. It has been confirmed that the tents are strictly adapted to the conditions in which they are used. Their diversification is the result of the experience of many generations of nomads: observing the routes they traveled and the materials they could use. Tests of tent models covered with hand-made goat hair fabric showed that it is more useful for strengthening the structure of the tent and protecting its interior than fabrics used today for a similar purpose.

  • UAV Photogrammetry under Poor Lighting Conditions—Accuracy Considerations
    • Paweł Burdziakowski
    • Katarzyna Bobkowska
    2021 Pełny tekst SENSORS

    The use of low-level photogrammetry is very broad, and studies in this field are conducted in many aspects. Most research and applications are based on image data acquired during the day, which seems natural and obvious. However, the authors of this paper draw attention to the potential and possible use of UAV photogrammetry during the darker time of the day. The potential of night-time images has not been yet widely recognized, since correct scenery lighting or lack of scenery light sources is an obvious issue. The authors have developed typical day- and night-time photogrammetric models. They have also presented an extensive analysis of the geometry, indicated which process element had the greatest impact on degrading night-time photogrammetric product, as well as which measurable factor directly correlated with image accuracy. The reduction in geometry during night-time tests was greatly impacted by the non-uniform distribution of GCPs within the study area. The calibration of non-metric cameras is sensitive to poor lighting conditions, which leads to the generation of a higher determination error for each intrinsic orientation and distortion parameter. As evidenced, uniformly illuminated photos can be used to construct a model with lower reprojection error, and each tie point exhibits greater precision. Furthermore, they have evaluated whether commercial photogrammetric software enabled reaching acceptable image quality and whether the digital camera type impacted interpretative quality. The research paper is concluded with an extended discussion, conclusions, and recommendation on night-time studies.

  • Uczelnia organizacją z domieszka turkusu - sznasa czy iluzja?
    • Krzysztof Leja
    • Aleksandra Pawlak
    2021 Pełny tekst e-mentor

    Po kilkuletnich dyskusjach nad przyszłym kształtem szkolnictwa wyższego w Polsce, zarówno na poziomie systemowym, jak i instytucjonalnym, w 2018 r. uchwalono ustawę Prawo o szkolnictwie wyższym i nauce, zwaną dalej Ustawą (2018). Regulacja ta wraz z pakietem rozporządzeń poszerzyła autonomię uczelni w zakresie organizacyjno-zarządczym, jednocześnie potęgując znaczenie ich rozliczalności. Wzmocnienie władzy rektora spowodowało zmianę postrzegania uczelni jako organizacji rozproszonych (Weick, 1976) w kierunku organizacji zwartych (Brunsson i Sahlin-Andersson, 2000) Autorzy opracowania dostrzegli, że koncepcja uczelni, zgodnie z literą i duchem Ustawy, nie zwraca należytej uwagi na relacje między pracownikami. Dlatego za cel artykułu uznano przedstawienie propozycji wdrożenia do instytucji akademickiej elementów coraz częściej opisywanej w literaturze naukowej – a równocześnie budzącej skrajne emocje – koncepcji organizacji turkusowej (Laloux, 2015). W artykule wskazano niewykorzystane, zdaniem autorów, możliwości zmian organizacyjno-zarządczych, jakie stworzyła Ustawa, a także opisano wybrane cechy organizacji turkusowej, odnosząc je do instytucji akademickiej. Ponadto zestawiono cechy uniwersytetu tradycyjnego, przedsiębiorczego oraz uniwersytetu z domieszką turkusu. W części badawczej przeanalizowano wywiady przeprowadzone z celowo wybranymi pracownikami Politechniki Gdańskiej, którzy wyrażali opinie dotyczące nowych rozwiązań organizacyjno-zarządczych zaproponowanych przez współautorkę artykułu podczas wywiadów. W podsumowaniu starano się odpowiedzieć na pytanie sformułowane w tytule.

  • Uczelnie kształcące polskich inżynierów elektryków do II wojny światowej
    • Dariusz Świsulski
    2021 Pełny tekst Przegląd Elektrotechniczny

    Na podstawie notek biograficznych ponad 1000 osób przedstawiono uczelnie, w których wykształcenie w latach 1891-1935 zdobywali polscy inżynierowie elektrycy. Do I wojny światowej były to uczelnie zagraniczne: niemieckie, rosyjskie, francuskie, belgijskie. Później Polacy kształcili się w polskich uczelniach: Politechnice Lwowskiej oraz w utworzonej w 1915 roku i szybko rozwijającej się Politechnice Warszawskiej.

  • Ukrainian Market of Electrical Energy: Reforming, Financing, Innovative Investment, Efficiency Analysis, and Audit
    • Ruslan Kostyrko
    • Tetiana Kosova
    • Lidiia Kostyrko
    • Liudmyla Zaitseva
    • Oleksandr Melnychenko
    2021 Pełny tekst ENERGIES

    The aim of this research is to determine the influence of electrical energy market regulation reform in Ukraine on the competitive environment, the reproduction processes of financial and innovative support, and the energy efficiency of the national economy. The authors have put forward and verified the hypothesis that, under conditions of institutional maturity of the Ukrainian electrical energy market, its liberalization and separation of the kinds of activity related to generation, transmission, and distribution leads to a decrease in prices, and the level of economic concentration stimulates implementation of innovations and the formation of reports on sustainable development. Over the thirteen-year time interval, a steady trend of decreasing energy intensity of the Ukrainian economy was established, and the appropriateness of energy efficiency management based on strategic targets was substantiated. The electricity market model in Ukraine is defined as a hybrid one, with an emphasis on trade under bilateral agreements. It was statistically found that liberalization of the electrical energy market in Ukraine contributed to a decrease in prices, with the exception of the areas of largest household and non-household consumers. The high level of asset concentration in the accounts of large enterprises was revealed, and the conclusion concerning the improvement of the competitive environment in the electricity production sector and the existence of the features of natural monopolies in the areas of transmission and distribution of electricity was made. The assessment of the financial competitive ability and profitability of electrical energy market entities was made, the main entities of the investment activity and the sources of their financing were characterized, and innovations were emphasized. The role of the standards of the audit of integrated reporting of the Ukrainian energy holdings and their role in ensuring sustainable development was determined.

  • Ulepszanie podłoża gruntowego i podtorza z użyciem środków strzałowych
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Mariusz Wyroślak
    2021

    Szybka i skuteczna metoda wzmacniania podłoża gruntowego i podtorza z wykorzystaniem środków strzałowych (zastrzeżona nazwa handlowa: metoda mikrowybuchów) pozwala projektować i budować drogi kolejowe na gruntach o obniżonej nośności (np. tereny podmokłe, bagna, odpady przemysłowe, komunalne, zdegradowane nasypy antropogeniczne). Jest przydatna i godna polecenia przy budowie nowych linii kolejowych, modernizacji istniejących oraz naprawach bieżących i głównych (często powiązanych z modernizacją). Prawidłowo wzmocnione podłoże gruntowe i podtorze jest gwarantem niezawodności danej linii kolejowej. Zwiększa żywotność trasy i bezpieczeństwo prowadzonego ruchu kolejowego.

  • Ultimate compressive strength assessment of uncleaned and cleaned corroded plates with locked crack
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2021 Pełny tekst Polish Maritime Research

    The work presented here investigates the structural response of cleaned corroded plates, subjected to compressive load in the presence of a locked crack, where the change of mechanical properties as a result of corrosion development and the cleaning process is also accounted for. A Finite Element model for assessing the compressive strength, considering geometric and material nonlinearities, is developed, and the analysed plates are compared with the available experimental data. An experimental design plan is generated using the Design of Experiments techniques, which quantifies the influence of the governing variables and their interactions with respect to the plate's ultimate compressive strength. With a limited number of observations, the most significant effects are identified. The corrosion degradation is revealed to be the most crucial effect leading to an effective strength reduction. It was found that, in the case of a corroded plate with a locked crack subjected to a compressive load, the most severe case is when the crack is transversely oriented. The strength reduction is slightly lower than when the corrosion degradation and the presence of a crack are considered to be a simple summation of these two effects but acting separately. The outcome of the analysis is the development of several empirical formulations that allow a fast estimation of the ultimate strength of a corroded plate, subjected to compressive load in the presence of a locked crack, accounting for different cleaning.

  • Ultimate strength of stiffened plates subjected to compressive load and spatially distributed mechanical properties
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2021

    The present study deals with the ultimate strength of stiffened plates subjected to spatially distributed mechanical properties and compressive load. Normally, mean values of mechanical properties based on tensile tests are used to validate the numerical assessment with experimental results. However, mechanical properties may vary within a single specimen. To investigate the impact of that, random fields of yield stress and Young modulus are employed together with the FE method. The variations of mechanical properties are estimated based on tensile tests. Different parameters of the random field are analysed, showing that the structural response will be different when compared with the stiffened plate with constant mechanical properties. Finally, it was revealed that the variation of yield stress has a significant impact, and Young modulus uncertainties play a secondary role. It is concluded, that the spatial variation of mechanical properties need to be considered when validating the numerical assessment with experimental measurements.

  • Ultrafiltration Process in Disinfection and Advanced Treatment of Tertiary Treated Wastewater
    • Rafał Bray
    • Katarzyna Jankowska
    • Eliza Kulbat
    • Aneta Łuczkiewicz
    • Aleksandra Sokołowska
    2021 Pełny tekst Membranes

    The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation)

  • Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode
    • Paweł Niedziałkowski
    • Magdalena Bojko
    • Jacek Ryl
    • Anna Wcisło
    • Marta Spodzieja
    • Katarzyna Magiera Mularz
    • Katarzyna Guzik
    • Grzegorz Dubin
    • Tad A. Holak
    • Tadeusz Ossowski
    • Sylwia Rodziewicz-Motowidło
    2021 Pełny tekst BIOELECTROCHEMISTRY

    This work describes the modification of a gold electrode with the BMS-8 compound that interacts with the Programmed Death-Ligand 1 (PD-L1), an immune checkpoint protein. The results show that we can confirm the presence of the sPD-L1 in the concentration range of 10−18 to 10−8 M using electrochemical impedance spectroscopy (EIS) with a limit of detection (LOD) of 1.87 × 10−14 M for PD-L1 (S/N = 3.3) and at a concentration of 10−14 M via cyclic voltammetry (CV). Additionally, high-resolution X-ray photoelectron spectroscopy (XPS), contact angle, and surface free energy measurements were applied to confirm the functionalization of the electrode. We investigated the selectivity of the electrode for other proteins: Programmed Death-1 (PD-1), cluster of differentiation 160 (CD160), and B- and T-lymphocyte attenuator (BTLA) at concentrations of 10−8 M. Differentiation between PD-L1 and PD-1 was achieved based on the analysis of the capacitance effect frequency dispersion at the surface of the modified Au electrode with BMS-8 after incubation at various concentrations of PD-L1 and PD-1 proteins in the range of 10−18 to 10−8 M. Significant differences were observed in the heterogeneity of PD-L1 and PD-1. The results of the quasi-capacitance studies demonstrate that BMS-8 strongly and specifically interacts with the PD-L1 protein.

  • Ultrasonic-assisted Electrodeposition of Cu-Sn-TiO2 Nanocomposite Coatings with Enhanced Antibacterial Activity
    • Dmitry Kharitonov
    • Aliaksandr Kasach
    • Denis Sergievich
    • Angelika Wrzesińska
    • Izabela Bobowska
    • Kazimierz Darowicki
    • Artur Zieliński
    • Jacek Ryl
    • Irina Kurilo
    2021 Pełny tekst ULTRASONICS SONOCHEMISTRY

    Copper-based coatings are known for their high antibacterial activity. In this study, nanocomposite Cu–Sn–TiO2 coatings were obtained by electrodeposition from an oxalic acid bath additionally containing 4 g/dm3 TiO2 with mechanical and ultrasonic agitation. Ultrasound treatment was performed at 26 kHz frequency and 32 W/dm3 power. The influence of agitation mode and the current load on the inclusion and distribution of the TiO2 phase in the Cu–Sn metallic matrix were evaluated. Results indicated that ultrasonic agitation decreases agglomeration of TiO2 particles and allows for the deposition of dense Cu–Sn–TiO2 nanocomposites. It is shown that nanocomposite Cu–Sn–TiO2 coatings formed by ultrasonic-assisted electrodeposition exhibit excellent antimicrobial properties against E. coli bacteria.

  • Ultrasound-assisted wet-impregnation of Ag–Co nanoparticles on cellulose nanofibers: Enhanced catalytic hydrogenation of 4-nitrophenol
    • Vividha K. Landge
    • Shirish H. Sonawane
    • Sivakumar Manickam
    • G.Uday Bhaskar Babu
    • Grzegorz Boczkaj
    2021 Journal of Environmental Chemical Engineering

    In this study, a novel nanocomposite of bimetallic Ag–Co nanoparticles supported on cellulose nanofibers (CNFs) was synthesised using the ultrasound-assisted wet-impregnation method for catalytic applications. CNFs were prepared from cellulose acetate using the electrospinning technique. Fourier transform infrared spectroscopy (FTIR) analysis confirmed the successful synthesis of CNFs. Further, scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) revealed a uniform dispersion of Ag and Co metals on the CNFs. At the same time, X-Ray diffraction (XRD) spectra indicated the highly crystalline nature of the as-produced composite. The hydrogenation of 4-nitrophenol (4-NP) was used to study the efficiency of the synthesised nanocomposite. The progress of the reaction was examined via UV–visible spectroscopy. It was noted that Ag-Co nanoparticles supported on CNFs catalysed the hydrogenation of 4-NP (0.1 mM) to 4-aminophenol within just 110 s with an apparent rate constant of 0.0172 s−1. This study proved that the obtained catalysts have superior stability and reusability with about 100% conversion up to 5 cycles. The excellent activity of the as-synthesised Ag-Co/CNFs nanocomposites makes it a promising nanocatalyst for catalytic applications.

  • Understanding Knowledge-Intensive Business Services. Identification, Systematization, and Characterization of Knowledge Flows
    • Małgorzata Zięba
    2021 Pełny tekst

    This book contributes to an improved understanding of knowledge-intensive business services and knowledge management issues. It offers a complex overview of literature devoted to these topics and introduces the concept of ‘knowledge flows’, which constitutes a missing link in the previous knowledge management theories. The book provides a detailed analysis of knowledge flows, with their types, relations and factors influencing them. It offers a novel approach to understand the aspects of knowledge and its management not only inside the organization, but also outside, in its environment.

  • Understanding the capacitance of thin composite films based on conducting polymer and carbon nanostructures in aqueous electrolytes
    • Anita Cymann-Sachajdak
    • Magdalena Graczyk-Zajac
    • Grzegorz Trykowski
    • Monika Wilamowska-Zawłocka
    2021 Pełny tekst ELECTROCHIMICA ACTA

    In this work electrochemical performance of thin composite films consisted of poly(3,4-ethylenedioxythiophene) (PEDOT), graphene oxide (GOx) and oxidized multiwalled carbon nanotubes (oxMWCNTs) is investigated in various sulphates (Li2SO4, Na2SO4, K2SO4, MgSO4) and acidic (H2SO4) electrolytes. Capacitance values, rate capability and cycling stability achieved for the composite layers are correlated with the electrolytes’ properties such as the conductivity, viscosity, cation size and pH. The highest capacitance values are achieved in acidic solution (98.6 mF cm−2 at 1 mA cm−2), whereas cycling stability is better in neutral electrolytes (88.4% of initial capacitance value after 10’000 cycles recorded for symmetric supercapacitor in 0.5 M MgSO4 solution). Diffusion controlled and non-diffusion controlled capacitance contributions are calculated and the results are discussed considering various ranges of sweep rates taken into account in the linear fitting and extrapolation of parameters.

  • Understanding the interactions between protein stabilizers and the peptide bond through the analysis of the volumetric and compressibility properties for the model systems
    • Emilia Kaczkowska
    • Jarosław Wawer
    • Magdalena Tyczyńska
    • Małgorzata Jóźwiak
    • Joanna Krakowiak
    2021 Pełny tekst JOURNAL OF CHEMICAL THERMODYNAMICS

    This work confirms our earlier supposition, that volumetric and acoustic parameters for simple model proposed by us are directly related to stabilizing/destabilizing effect of osmolytes on proteins structure. The apparent molar volumes, V and the apparent molar isentropic compressions, KS,, of glycine and N,N,N –trimethylglycine (betaine) were determined from densities and speed of sound measurements in aqueous solution of N-methylacetamide (as a model of peptide bond of protein). The standard molar parameters for osmolytes were obtained from concentration dependence of the calculated quantities at NMA concentration equal 2, 4, 6 and 8 (mol/kg) and at temperature T = (288.15, 298.15 and 308.15) K. The standard values were combined with volumetric and compressibility data for amino acids in pure water to obtain transfer properties from water to aqueous N-methylacetamide solutions. The standard partial molar volume of transfer of studied osmolytes, 〖Δ_t V〗_Φ^0, seems to be related mainly to hydrophilic/hydrophobic features of molecules. The stabilizing/destabilizing effect of solute on protein structure is reflected in temperature influence on the limiting partial molar quantities.

  • Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
    • Jan Schmidt
    • Aleksander Schmidt
    2021 Pełny tekst Vibrations in Physical Systems

    The implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with Rician fading, reflecting the short- and mediumrange shallow water channels. The simulation also took into account the presence of additive Gaussian noise in the channel on the functioning of the receiver. The obtained results prove the high reliability of the underwater communication system based on broadband HFM signals.

  • Unexpected Z/E isomerism of N-methyl-O-phosphothioyl benzohydroxamic acids, their oxyphilic reactivity and inertness to amines
    • Arkadiusz Majewski
    • Jarosław Chojnacki
    • Witold Przychodzeń
    2021 Pełny tekst STRUCTURAL CHEMISTRY

    Thiophosphinoylation of N-methyl p-substituted benzohydroxamic acids using disulfanes (method A) or diphenylphosphinothioyl chloride (method B) provides only one conformer of the respective O-phosphothioyl derivative (Xray and NMR analysis). Undergoing the P-transamidoxylation reaction is an evidence of the reversibility of thiophosphinoylation. Only those products containing strong EWG substituents in the aroyl residue or bulky substituents at the phosphorus atom possess E conformation. DFT calculations confirmed the energetic domination of each isomer. The Z-isomers are distorted amides having both high degree of nitrogen pyramidalization (38–55°) and amide twist (12–30°). In solution they exist in a defined conformation that is evidenced by the presence of a sharp signal of N-methyl protons at low temperature. They do not isomerize in solutions. Some of them slowly undergo the N-O bond scission above 100 °C. Both isomers are not as sensitive to neutral hydrolysis as twisted amides can be and are inert toward amines. The rate of alkaline hydrolysis can be correlated with pKa of hydroxamic acid. Because of their outstanding oxyphilicity, these compounds can be defined as nerve agent surrogates and safer alternatives of phosphorus fluorides for serine-active enzyme inhibition studies

  • Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
    • Waldemar Jendernalik
    • Jacek Jakusz
    • Robert Piotr Piotrowski
    • Grzegorz Blakiewicz
    • Stanisław Szczepański
    2021 Pełny tekst Electronics

    A voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology, also designed in the same process. Simulations show that, with the same supply (1.8 V), power (1.2 mW), load (12 pF), bandwidth (50 MHz), and similar area (600 m2), the proposed buffer achieves the lowest gain error (0.3%) and the highest PSRR (72 dB).

  • University Students’ Research on Artificial Intelligence and Knowledge Management. A Review and Report of Multi-case Studies
    • Mieczysław Owoc
    • Paweł Weichbroth
    2021 Pełny tekst

    Leading technologies are very attractive for students preparing their theses as the completion of their studies. Such an orientation of students connected with professional experiences seems to be a crucial motivator in the research in the management and business areas where these technologies condition the development of professional activities. The goal of the paper is the analysis of students’ thesis topics defended in the last 10 years in business informatics and computer science in two selected universities in Poland. Our study relies on a detailed review and analysis of qualitative data, obtained from a literature review and multi-case-study research. In the case of the artificial intelligence domain, we have identified six areas of research, namely: general AI, machine learning (ML), natural language processing (NLP), artificial neural networks (ANNs), expert systems, and hybrids. In the case of the knowledge management domain, we have recognized eleven areas of research, regarding the following sectors: e-government, technology, space exploration, social media, manufacturing, healthcare, finance, entertainment, education, e-commerce, and business. Future research will be directed toward extending the scope by including other regions and universities as well as identifying and analyzing students’ motivational factors, associated with research projects and higher education.

  • Uniwersalny Kontroler Radiowy w systemie STRADAR
    • Sylwester Kaczmarek
    • Mariusz Miszewski
    • Marcin Wyczyński
    2021 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Opisano praktyczne rozwiązanie uniwersalnego kontrolera radiowego UKR – jednego z podstawowych elementów funkcjonalnych systemu STRADAR – który obsługuje sensory wykorzystywane na granicy morskiej państwa. Jest on także odpowiedzialny za komunikację personelu Straży Granicznej. UKR ma dwie wersje, jedną mobilną – na jednostki pływające, pojazdy lądowe i jednostki latające, drugą stacjonarną – na stałe punkty obserwacyjne rozmieszczone wzdłuż granicy. Urządzenie to uzyskało pozytywny wynik testów akceptacyjnych oraz badań certyfikacyjnych i osiągnęło IX poziom gotowości technologii.

  • Upamiętnianie w zdecentralizowanej formule
    • Agnieszka Gębczyńska-Janowicz
    2021

    Realizacje kommemoratywne tworzone obecnie w przestrzeni publicznej udowadniają, e definicja pomnika jest niejednoznaczna, wynika z różnych aspektów twórczości i dostosowuje się do kontekstu kulturowego epoki. Celem artykułu jest analiza współczenej realizacji formuły zdecentralizowanej.

  • Uptake, accumulation, and translocation of Zn, Cu, Pb, Cd, Ni, and Cr by P. australis seedlings in an urban dredged sediment mesocosm: impact of seedling origin and initial trace metal content
    • Nicole Nawrot
    • Ewa Wojciechowska
    • Ksenia Pazdro
    • Jacek Szmagliński
    • Janusz Pempkowiak
    2021 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    The study presents results from 6 months of phytoremediation of sediments dredged from three urban retention tanks carried out in a mesocosm setup with the use of P. australis. Two kinds of P. australis seedlings were considered: seedlings originating from natural (uncontaminated - Suncont) and anthropogenically changed environments (contaminated – Scont); this distinction was reflected in the baseline concentrations of trace metals inside their tissues. The potentially toxic elements (PTEs) considered in this study were as follows: Zn, Cu, Cd, Ni, Cr, and Pb. The aim of the study was to compare the uptake, accumulation, and translocation properties of seedlings with different initial trace metal contents. The PTE concentrations were analyzed in sediments as well as in belowground and aboveground parts of plants in the middle (3rd month) and at the end of the investigation period using inductively coupled plasma mass spectrometry (ICP-MS), and the accumulation of PTEs in plant tissues was calculated. Phytoextraction efficiency was evaluated using the bioconcentration factor (BF) and translocation factor (TF). Plant morphology was assessed with scanning electron microscopy (SEM) to document plant stress due to PTE exposure. The results of our study indicated that P. australis seedlings originating from sites differing in the initial trace metal content exhibited different behavior when grown on sediments dredged from urban retention tanks. Suncont seedlings with low initial metal contents tended to adapt to the dredged sediments and showed phytoextraction ability, while Scont seedlings originating from sites with initial high contents of trace metals acted as phytoexcluders and tended to release PTEs from their tissues into the sediments. The morphological and structural effects caused by metal toxicity were observed in growth limitation, root tissue disturbance, root hair number decrease, and structural alterations in the epidermis and endodermis. Therefore, the Suncont seedlings presented better properties and adaptability for phytoremediation purposes.

  • Urban Lighting Research Transdisciplinary Framework—A Collaborative Process with Lighting Professionals
    • Catherine Vega, Pérez
    • Karolina Zielińska-Dąbkowska
    • Franz Hölker
    2021 Pełny tekst International Journal of Environmental Research and Public Health

    Over the past decades, lighting professionals have influenced the experience of the night by brightly illuminating streets, buildings, skylines, and landscapes 24/7. When this became the accepted norm, a dual perspective on night-time was shaped and the visual enjoyment of visitors after dusk was prioritized over natural nightscapes (nocturnal landscapes). During this time, researchers of artificial light at night (ALAN) observed and reported a gradual increase in unnatural brightness and a shift in color of the night-time environment. As a consequence, ALAN has been identified as a relevant pollutant of aquatic and terrestrial habitats, and an environmental stressor, which may adversely affect a wide range of organisms, from micro-organisms to humans. Unfortunately, lighting professionals and ALAN researchers usually attempt to solve today’s sustainable urban lighting problems distinctive to their fields of study, without a dialogue between research and practice. Therefore, in order to translate research knowledge as an applicable solution for the lighting practice and to minimize the impact on the environment, a collaborative framework involving a transdisciplinary process with lighting professionals is crucial to potentially bring the practice, research, production, decision-making, and planning closer to each other. This paper presents a framework to help reduce the existing gap of knowledge, because appropriate lighting applications depend upon it. Access to less light polluted nightscapes in urban environments is just as important as access to unpolluted water, food, and air. This call for action towards sustainable urban lighting should be included in future lighting policies to solve the urgent environmental and health challenges facing our world.

  • Use of Bi-Temporal ALS Point Clouds for Tree Removal Detection on Private Property in Racibórz, Poland
    • Patrycja Przewoźna
    • Paweł Hawryło
    • Karolina Zięba-kulawik
    • Adam Inglot
    • Krzysztof Mączka
    • Piotr Wężyk
    • Piotr Matczak
    2021 Pełny tekst Remote Sensing

    Trees growing on private property have become an essential part of urban green policies. In many places, restrictions are imposed on tree removal on private property. However, monitoring compliance of these regulations appears difficult due to a lack of reference data and public administration capacity. We assessed the impact of the temporary suspension of mandatory permits on tree removal, which was in force in 2017 in Poland, on the change in urban tree cover (UTC) in the case of the municipality of Racibórz. The bi-temporal airborne laser scanning (ALS) point clouds (2011 and 2017) and administrative records on tree removal permits were used for analyzing the changes of UTC in the period of 2011–2017. The results show increased tree removal at a time when the mandatory permit was suspended. Moreover, it appeared that most trees on private properties were removed without obtaining permission when it was obligatory. The method based on LiDAR we proposed allows for monitoring green areas, including private properties.

  • Using deep learning to increase accuracy of gaze controlled prosthetic arm
    • Tomasz Kocejko
    2021

    This paper presents how neural networks can be utilized to improve the accuracy of reach and grab functionality of hybrid prosthetic arm with eye tracing interface. The LSTM based Autoencoder was introduced to overcome the problem of lack of accuracy of the gaze tracking modality in this hybrid interface. The gaze based interaction strongly depends on the eye tracking hardware. In this paper it was presented how the overall the accuracy can be slightly improved by software solution. The cloud of points related to possible final positions of the arm was created to train Autoencoder. The trained model was next used to improve the position provided by the eye tracker. Using the LSTM based Autoencoder resulted in nearly 3% improvement of the overall accuracy.

  • Using Evidence-based Arguments to Support Dependability Assurance - Experiences and Challenges
    • Janusz Górski
    2021 ACM SIGAda Ada Letters

    The presentation introduces to the problem of evidence-based arguments and their applications. Then, based on the experiences collected during development and commercial deployment of a concrete solution to this problem (system NOR-STA) we overview selected challenges and the ways of addressing them.

  • Using FreeFEM open software for modelling the vibrations of piezoelectric devices
    • Marek Moszyński
    2021 Pełny tekst Vibrations in Physical Systems

    Modelling vibrations of piezoelectric transducers has been a topic discussed in the literature for many decades. The first models - so-called one-dimensional - describe the vibrations only near operating frequency and near its harmonics. Attempts to introduce two-dimensional models were related to the possibility of one transducer working at several frequencies, including both thickness vibrations and those resulting from the transducer horizontal dimensions. In recent decades, thanks to the use of the finite element method and its derivatives, and the progress related to the increase in processor speed and memory availability, the implementation of models based on three-dimensional modelling is possible using software on personal computers. As the implementation of finite element method algorithms is characterized by high complexity, several professional software packages have been created on the commercial market, among which only a few implement the piezoelectric equations. In this context, this article presents how to use open source software along with developed programming language for intuitive definition of piezoelectric equations and its solution.

  • Using the ultrasonic tomography method to study the condition of wooden beams from historical buildngs
    • Monika Zielińska
    • Magdalena Rucka
    2021

    The need to evaluate the integrity of wooden structural elements is constantly increasing. Non-destructive methods are becoming more popular in this field of research. One type of non-destructive testing is the ultrasonic imaging method, which allows the analysis of internal wood structures without disturbing their state and integrity. In this study, we are interested in assessing the effect of wood condition on the ultrasound time of flight (TOF). The research was carried out on wooden beams, which were obtained from a historical building. The images obtained from ultrasound tomography were compared with results of a visual inspection.Places of discontinuities, voids and cracks in wood caused a much lower velocity of wave propagation.The location of the wood core was illustrated by the places with the highest velocity. The article proved the validity of using ultrasonic tomography to assess the technical condition of historic wooden beams.