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Gdańsk University of Technology

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  • Influence of Thermal Decomposition of Wood and Wood-Based Materials on the State of the Atmospheric Air. Emissions of Toxic Compounds and Greenhouse Gases
    • Przemysław Rybiński
    • Bartłomiej Syrek
    • Mirosław Szwed
    • Dariusz Bradło
    • Witold Żukowski
    • Anna Marzec
    • Magdalena Śliwka-Kaszyńska
    2021 Full text ENERGIES

    This paper presents the energy characteristics of wood and wood-based materials in the form of commercially available pellets, furniture board (MDF) and OSB. Toxicometric indices were determined for gaseous destructs arising from thermal decomposition and combustion of the materials studied. The paper proves that combustion conditions are crucial in terms of toxic destructive emissions. It has been shown that the combustion of wood-based materials under controlled conditions can lead to equally low emissions of toxic wastes as the combustion of traditional wood materials. The paper also presents the index of greenhouse gas emission, the so-called CO2 equivalent, for the examined wood and wood-based materials.

  • INFOGEST inter-laboratory recommendations for assaying gastric and pancreatic lipases activities prior to in vitro digestion studies
    • Myriam M.L. Grundy
    • Evan Abrahamse
    • Annette Almgren
    • Marie Alminger
    • Ana Andres
    • Renata M.C. Ariëns
    • Shanna Bastiaan-Net
    • Claire Bourlieu-Lacanal
    • André Brodkorb
    • Maria Rosário Bronze
    • Irene Comi
    • Leslie Couëdelo
    • Didier Dupont
    • Annie Durand
    • Sedef N. El
    • Tara Grauwet
    • Christine Heerup
    • Ana Heredia
    • Marcos R. Infantes Garcia
    • Christian Jungnickel
    • Ilona Kłosowska-Chomiczewska
    • Marion Létisse
    • Adam Macierzanka
    • Alan Mackie
    • David McClements
    • Olivia Menard
    • Anne Meynier
    • Marie-Caroline Michalski
    • Ana-Isabel Mulet-Cabero
    • Anette Mullertz
    • Francina M. Payeras Perelló
    • Irene Peinado
    • Mélina Robert
    • Sébastien Secouard
    • Ana Teresa Serra
    • Sandra D. Silva
    • Gabriel Thomassen
    • Cecilia Tullberg
    • Ingrid Undeland
    • Carole Vaysse
    • Gerd Vegarud
    • Sarah H.E. Verkempinck
    • Michelle Viau
    • Mostafa Zahir
    • Ruojie Zhang
    • Frédéric Carrière
    2021 Full text Journal of Functional Foods

    In vitro digestion studies often use animal digestive enzyme extracts as substitutes of human gastric and pancreatic secretions. Pancreatin from porcine origin is thus commonly used to provide relevant pancreatic enzymes such as proteases, amylase and lipase. Rabbit gastric extracts (RGE) have been recently introduced to provide gastric lipase in addition to pepsin. Before preparing simulated gastric and pancreatic extracts with targeted enzyme activities as described in in vitro digestion protocols, it is important to determine the activities of enzyme preparations using validated methods. The purpose of this inter-laboratory study within the INFOGEST network was to test the repeatability and reproducibility of lipase assays using the pH-stat technique for measuring the activities of gastric and pancreatic lipases from various sources. Twenty-one laboratories having different pH-stat devices received the same protocol with identical batches of RGE and two pancreatin sources. Lipase assays were performed using tributyrin as a substrate and three different amounts (50, 100 and 200 µg) of each enzyme preparation. The repeatability results within individual laboratories were satisfactory with coefficients of variation (CVs) ranging from 4 to 8% regardless of the enzyme amount tested. However, the inter-laboratory variability was high (CV > 15%) compared to existing standards for bioanalytical assays. We identified and weighted the contributions to inter-laboratory variability of several parameters associated with the various pH-stat equipment used in this study (e.g. reaction vessel volume and shape, stirring mode and rate, burette volume for the automated delivery of sodium hydroxide). Based on this, we established recommendations for improving the reproducibility of lipase assays using the pH-stat technique. Defining accurate and complete recommendations on how to correctly quantify activity levels of enzyme preparations is a gateway to promising comparison of in vitro data obtained from different laboratories following the same in vitro digestion protocol.

  • Informal Settlements and International Migrants: The city of Rome (Italy) as Case Study
    • Saira Abbasi
    • Cristiana Lauri
    2021 Full text

    Today, urbanization is happening at an unprecedentedly rapid rate, owing heavily to the influx of migrants. Empirical evidence shows the development of informal settlements in cities as a result of migration, including Rome. Furthermore, information on informal settlements is either insufficient or inadequate, which makes it challenging for architects, urban planners, and policymakers to form viable solutions to deal with the situations of informality. The main focus of the research is to study the Authorized Nomadic Camps, illegal and tolerated squatter settlements of the of Rome from 1990-2021, and the laws, regulations, and policies that have shaped them. Mixed research methodology and descriptive-analytical techniques are used to analyze the data collected via field research, site visit, interviews, and study of existing literature and maps. The analysis of morphological changes of the selected sites is done using images from Goggle Earth Time Lapse dating from 2001 – 2021. This research identifies that most of the settlements have been located by the Municipality in segregated and marginalized areas of the city with poor transport and mobility, and inadequate conditions of housing, access to services. Furthermore, the Gordiani Campo Nomadi need not be entirely evacuated and demolished, as it and the area around Via Gordiani have the potential to be developed in a way that meets the needs of all stakeholders, and most importantly the current dwellers of the camp. This will help alleviate the sense of trauma and loss experienced by uprooting and evicting them. Case studies and urban analysis reveals the involvement of the community, effective communication, and participation between all stakeholders are pertinent to design long-term sustainable solutions.

  • Information and communication technologies versus diffusion and substitution of financial innovations. The case of exchange-traded funds in Japan and South Korea
    • Adam Marszk
    • Ewa Lechman
    2021

    The substitution between financial innovations, exchange-traded funds (ETFs), and stock index derivatives (i.e. index financial instruments) is one of the relatively understudied topics of the financial sciences. The current study aims to verify empirically the diffusion and substitution of ETFs in the market for index financial instruments. It presents in-depth analysis of the development of index financial instruments traded on the stock exchanges in two key Asian economies: Japan and South Korea. The development of the ETF markets (i.e. diffusion of ETFs) was confirmed for both countries. Moreover, through the technological substitution analysis, we confirmed the process of gradual substitution between stock index options and ETFs, with the increasing role of the innovative products noticeable in some periods (the empirical study used monthly data for 2003–2015). Additionally, we verified empirically the linkages between information and communication technologies (ICTs) penetration and the diffusion of ETFs in Japan and South Korea, using extended dataset for 2004–2019 and applying country-specific regression models. We found that increases in ICT are associated with the growing market share of ETFs in both countries.

  • Inhibition of Polymer Photodegradation by Incorporation of Coffee Silverskin
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Olga Mysiukiewicz
    2021 Full text Proceedings

    Over the last years, the trend associated with the incorporation of materials from renewable resources into polymer technology is getting significantly more vital. Researchers are trying to transfer the properties of natural raw materials into the polymer world. Therefore, different natural materials are more often investigated as potential additives for polymers. Such an effect is noted for the coffee industry by-products, such as coffee silverskin. Because of the relatively high contents of compounds showing antioxidant activity, such as caffeine, polyphenols, tannins, or melanoidins, this by-product could be considered not only as a filler, but also as a potential modifier for polymer materials. Its antioxidant activity is comparable to commercially available antioxidants applied in polymer technology. Therefore, in the presented paper, we examined the influence of the coffee silverskin (from 1 to 20 wt%) on the thermal and mechanical performance of polyethylene-based composites. Moreover, materials were subjected to accelerated aging tests in the UV chamber, which revealed that coffee silverskin could inhibit the photodegradation of the polymer matrix. Therefore, this by-product should be considered as an exciting alternative for the conventional lignocellulosic fillers, which could provide additional features to polymer composites.

  • Initial Report on Numerical Modeling of Blood Flow in Myocardial Bridge Region of Coronary Artery: Concept of Model Validation
    • Bartłomiej Melka
    • Marcin Nowak
    • Marek Rojczyk
    • Maria Gracka
    • Wojciech Adamczyk
    • Ziemowit Ostrowski
    • Ryszard Białecki
    2021

    The paper presents a numerical method of blood flow simulation within the coronary artery covered by the myocardial bridge. The myocardial bridge is a congenital coronary abnormality caused by the blood vessel location under one of the heart muscles. In this case, the blood flow within the vessel is partially disturbed which can cause several consequences. The presented numerical simulation allowed us to estimate the blood flow accompanied by the wall movement using dynamic mesh settings. In parallel to the numerical investigation, the experimental research was developed. A test rig was built to reconstruct the vessel wall motion occurring under the myocardial bridge in the in-vitro conditions.

  • Inner-shell fragmentation of molecules into neutral fragments in high-Rydberg states induced by soft X-ray excitation with pulsed-field ionization
    • Tomasz Wąsowicz
    2021

    In the present communication, we will show the results of measurements probing the production of neutral high-Rydberg fragments at the K edges of the molecules containing oxygen and nitrogen atoms. The experiments were performed at the Gas Phase beamline of the Elettra synchrotron radiation laboratory (Trieste, Italy), exploiting a combined soft X-ray excitation with pulsed-field ionization and ion time-of-flight (TOF) spectrometry [4]. These measurements revealed the ultrafast photoelectron recapture process [4-6], where the photoelectron is pushed back to the HR orbital of the molecular ion. This reaction occurs via the population of val-2HR1 states, whose dissociation can then yield neutral fragments in HR states.

  • Innovative mobile method to determine railway track axis position in global coordinate system using position measurements performed with GNSS and fixed base of the measuring vehicle
    • Andrzej Wilk
    • Władysław Koc
    • Cezary Specht
    • Jacek Skibicki
    • Sławomir Judek
    • Krzysztof Karwowski
    • Piotr Chrostowski
    • Jacek Szmagliński
    • Paweł Dąbrowski
    • Krzysztof Czaplewski
    • Mariusz Specht
    • Roksana Licow
    • Sławomir Grulkowski
    2021 Full text MEASUREMENT

    The shape of the railway track axis and its position in the global coordinate system are essential when defining design parameters of the railway. Correct reconstruction of these quantities is vital for both verifying the compliance of real track parameters with the design and for diagnosing, as all track deformations can also be defined as deviations of real parameters from their design values. The measurements of quantities related to the railway track geometry can be divided into global and local ones. Global measurements determine the position of elements in the global system of geographic coordinates, while local measurements give relative positions of elements with respect to other elements (e.g. lateral inclination at a given kilometre of the railway track) or temporary deviation of parameters from their assumed value (e.g. various track deformations). Depending on the applied measuring method, either global or local parameters are determined, or both of them simultaneously. The article proposes an innovative method to determine the railway track axis position, which makes use of Global Navigation Satellite Systems (GNSS) receivers distributed in such a way as to form a geometric constraint called the fixed base. The analysis of theoretical properties and metrological attributes of the fixed base is presented. All theoretical analyses have been verified experimentally.

  • In-Out Surface Modification of Halloysite Nanotubes (HNTs) for Excellent Cure of Epoxy: Chemistry and Kinetics Modeling
    • Shahab Moghari
    • Seyed Hassan Jafari
    • Mohsen Khodadadi Yazdi
    • Maryam Jouyandeh
    • Aleksander Hejna
    • Payam Zarrintaj
    • Mohammad Saeb
    2021 Full text Nanomaterials

    In-out surface modification of halloysite nanotubes (HNTs) has been successfully performed by taking advantage of 8-hydroxyquinolines in the lumen of HNTs and precisely synthesized aniline oligomers (AO) of different lengths (tri- and pentamer) anchored on the external surface of the HNTs. Several analyses, including FTIR, H-NMR, TGA, UV-visible spectroscopy, and SEM, were used to establish the nature of the HNTs’ surface engineering. Nanoparticles were incorporated into epoxy resin at 0.1 wt.% loading for investigation of the contribution of surface chemistry to epoxy cure behavior and kinetics. Nonisothermal differential scanning calorimetry (DSC) data were fed into home-written MATLAB codes, and isoconversional approaches were used to determine the apparent activation energy (Eα) as a function of the extent of cure reaction (α). Compared to pristine HNTs, AO-HNTs facilitated the densification of an epoxy network. Pentamer AO-HNTs with longer arms promoted an Excellent cure; with an Eα value that was 14% lower in the presence of this additive than for neat epoxy, demonstrating an enhanced cross-linking. The model also predicted a triplet of cure (m, n, and ln A) for autocatalytic reaction order, non-catalytic reaction order, and pre-exponential factor, respectively, by the Arrhenius equation. The enhanced autocatalytic reaction in AO-HNTs/epoxy was reflected in a significant rise in the value of m, from 0.11 to 0.28. Kinetic models reliably predict the cure footprint suggested by DSC measurements.

  • Insights into modification of lignocellulosic fillers with isophorone diisocyanate: structure, thermal stability and volatile organic compounds emission assessment
    • Aleksander Hejna
    • Mariusz Marć
    • Katarzyna Skórczewska
    • Joanna Szulc
    • Jerzy Korol
    • Krzysztof Formela
    2021 Full text European Journal of Wood and Wood Products (HOLZ ALS ROH-UND WERKSTOFF)

    This study presents an analysis of the structure and properties of different types of lignocellulosic fillers modified by isophorone diisocyanate (IPDI) to provide insights into the possibility of their application to the manufacturing of wood polymer composites (WPCs). Moreover, it deals with the environmental aspects of modified fillers, by assessment of volatile organic compounds (VOCs) emitted during modification, as well as from final products. Three types of commercially available lignocellulosic fillers were modified with different content of IPDI (from 1 to 15 wt%) using the internal mixer. The main compounds detected in the air during modifications were terpenes and terpenoids. No IPDI was detected, which is very beneficial considering its toxicity. On the other hand, IPDI was emitted from modified fillers at a slightly elevated temperature of 40 °C, which was associated with a significant rise in its vapor pressure. Successful modification of fillers was confirmed by FTIR spectroscopy and thermogravimetric analysis. Performed modifications of lignocellulosic fillers with IPDI had a relatively small impact on their particle size and color properties. Such an effect can be considered beneficial for the mechanical performance and appearance of WPCs, which could be potentially manufactured using IPDI-modified lignocellulosic fillers.

  • Insights into the Thermo-Mechanical Treatment of Brewers’ Spent Grain as a Potential Filler for Polymer Composites
    • Aleksander Hejna
    • Mariusz Marć
    • Daria Kowalkowska-Zedler
    • Agnieszka Pladzyk
    • Mateusz Barczewski
    2021 Full text Polymers

    This paper investigated the impact of twin-screw extrusion parameters on the properties of brewers’ spent grain. The chemical structure, antioxidant activity, particle size, and color properties, as well as the emission of volatile organic compounds during extrusion, were investigated. The main compounds detected in the air during modifications were terpenes and terpenoids, such as α-pinene, camphene, 3-carene, limonene, or terpinene. They could be considered as a potential threat to human health and the environment. Changes in the chemical structure, antioxidant activity, and color of materials after modification indicated the Maillard reactions during extrusion, which resulted in the generation of melanoidins, especially at higher temperatures. This should be considered an exciting feature of this treatment method because modified brewers’ spent grain may improve the thermooxidative stability of polymer materials. Moreover, the impact of the brewers’ spent grain particle size on color and browning index used to determine the melanoidins content was investigated. The presented results show that proper adjustment of extrusion parameters enables the preparation of brewers’ spent grain with the desired appearance and chemical properties, which could maximize the efficiency of the modification process.

  • Instructor Presence in Video Lectures: Preliminary Findings From an Online Experiment
    • Yen Ying Ng
    • Adam Przybyłek
    2021 Full text IEEE Access

    Motivation. Despite the widespread use of video lectures in online and blended learning environments, there is still debate whether the presence of an instructor in the video helps or hinders learning. According to social agency theory, seeing the instructor makes learners believe that s/he is personally teaching them, which leads to deeper cognitive processing and, in turn, better learning outcomes. Conversely, according to cognitive load theory, adding an image of the instructor may hinder attention engagement with lecture content due to split-attention effect. Not only are theoretical propositions conflicting, but so is the empirical evidence as well. Objective. This study investigates the effects of the presence of the instructor’s face in the corner of an educational video on learning outcomes, perceived cognitive load, and perceived social presence in the context of foreign language vocabulary learning. Method. In an online quasi-controlled experiment with between-subject design, 112 participants were randomly assigned to view a 10-min-long educational video in one of two conditions: instructor-present or instructor-absent. As for the latter condition, the face was shown only at the introduction of the presentation. Afterwards, participants completed a retention test as well as a cognitive load and social presence questionnaire. Results. No significant differences were found for any dependent variable. Conclusion. Individuals differ so much in their language aptitude as well as motivation to perform well that random assignment is probably not enough to ensure balanced groups in this particular study context. Besides, the approach that we used to measure cognitive load as well as social presence is not suited for between-subject design, even though it was previously used in such settings.

  • Integracyjne place zabaw
    • Marek Wysocki
    • Joanna Kowalewska
    2021

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  • Integrated membrane bioreactors modelling: A review on new comprehensive modelling framework
    • Jacek Mąkinia
    • Giorgio Mannina
    • Marion Alliet
    • Christoph Brepols
    • Joaquim Comas
    • Jarome Harmand
    • Marc Heran
    • Nesrine Kalboussi
    • Ángel Robles
    • Ferreira Taise Rebouças
    • Bing-Jie Ni
    • Ignasi Rodriguez-Roda
    • María Victoria Ruano
    • Giorgio Bertanza
    • Ilse Smets
    2021 BIORESOURCE TECHNOLOGY

    Integrated Membrane Bioreactor (MBR) models, combination of biological and physical models, have been representing powerful tools for the accomplishment of high environmental sustainability. This paper, produced by the International Water Association (IWA) Task Group on Membrane Modelling and Control, reviews the state-of-the-art, identifying gaps for future researches, and proposes a new integrated MBR modelling framework. In particular, the framework aims to guide researchers and managers in pursuing good performances of MBRs in terms of effluent quality, operating costs (such as membrane fouling, energy consumption due to aeration) and mitigation of greenhouse gas emissions.

  • Integrated plant-wide modelling for evaluation of the energy balance and greenhouse gas footprint in large wastewater treatment plants
    • Ewa Zaborowska
    • Krzysztof Czerwionka
    • Jacek Mąkinia
    2021 Full text APPLIED ENERGY

    Modern wastewater treatment plants (WWTPs) should maintain a balance between three combined sustainability criteria, including effluent quality, energy performance and greenhouse gas (GHG) emissions. All of these criteria were considered in the integrated plant-wide model developed in this study. The proposed model incorporates new features, including: (i) the addition of associated facilities to the overall energy balance and GHG footprint and (ii) the implementation and validation of detailed sub-models of heat and power supply and demand. The aim of the study was to investigate the implications of these new extensions on the energy balance and sustainability assessment of the entire facility. The integrated model was evaluated against full-scale data from a large WWTP performing biological nutrient removal in an activated sludge bioreactor and anaerobic digestion of sewage sludge. Upon applying the investigated operational strategies, the potential decreases in the GHG footprint and effluent total nitrogen concentration were estimated to be 20% and 30%, respectively, in comparison with the current conditions. However, only a slight potential for improving the overall energy balance was found. In contrast, with technological upgrades, energy neutrality and the highest reduction in the GHG footprint (by over 30%) were achieved, but the effluent quality remained unchanged in comparison with the current conditions. It was shown that the heat demand of associated facilities could not be neglected in the overall heat balance and GHG footprint. The detailed models of energy demand and supply improved the assessment of energy performance in the full-scale WWTP.

  • Integrating Digital Twin Technology Into Large Panel System Estates Retrofit Projects
    • Paulina Duch-Żebrowska
    • Katarzyna Zielonko-Jung
    2021 Full text Urban Planning

    As sustainability is now a standard for the proposed developments, the focus ought to be shifted towards the existing buildings and, among them, the worldwide stock of large panel system (LPS) buildings. Major upgrades and retrofits were done to some of the LPS estates in Germany and France, but a leading sustainable way must still be developed for LPS buildings in Eastern European countries, where apartments in those half‐a‐century‐old estates are privately owned. Both sustainability and ownership issues make the demolition option redundant, and therefore the method for deep thermal retrofit and urban intervention is being developed with the use of BIM simulation tools. Digital twin (DT) technology allows for calibration to intertwine with the Internet of Things applications that reward the inhabitants for sustainable behaviour while feeding the relevant data back to the DT. Thanks to this, smart technology can be used to raise the level of social participation in the projects and thus help educate the end‐users, which is paramount in establishing and maintaining good ecological habits, and as such, also for the efficacy and viability of the final endeavour. This article proposes a procedure of creating a 3D model typology repository for facilitating DT technology to provide a good analytical tool for community consultation and enable virtual testing of technical and urban solutions before implementation. It aims to determine the method for virtual technology to give deteriorating estates a new lease of life and improve their perception in the widercommunity while being a conduit for the adaptation of CEE to the digital revolution.

  • Integrating Experience-Based Knowledge Representation and Machine Learning for Efficient Virtual Engineering Object Performance
    • Syed Imran Shafiq
    • Cesar Sanin
    • Edward Szczerbicki
    2021 Full text Procedia Computer Science

    Machine learning and Artificial Intelligence have grown significant attention from industry and academia during the past decade. The key reason behind interest is such technologies capabilities to revolutionize human life since they seamlessly integrate classical networks, networked objects and people to create more efficient environments. In this paper, the Knowledge Representation technique of Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA) is applied to facilitate Machine Learning. For effective and efficient decision-making in Machine Learning, the environment's own experience is captured, stored and reused using the DDNA technique. The proposed approach is implemented on practical test cases like a Chatbot. Decisional DNA gathers explicit experiential knowledge based on formal decision events and uses this knowledge to support decision-making processes. The experimental test and results of the presented implementation of Decisional DNA Chatbot case studies support it as a technology that can improve and be applied to the technology, enhancing intelligence by predicting capabilities and facilitating knowledge engineering processes.

  • Integrating Statistical and Machine‐Learning Approach for Meta‐Analysis of Bisphenol A‐Exposure Datasets Reveals Effects on Mouse Gene Expression within Pathways of Apoptosis and Cell Survival
    • Nina Lukashina
    • Michael Williams
    • Elena Kartysheva
    • Elizaveta Virko
    • Błażej Kudłak
    • Robert Fredriksson
    • Ola Spjuth
    • Helgi B. Schiöth
    2021 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Bisphenols are important environmental pollutants that are extensively studied due to different detrimental effects, while the molecular mechanisms behind these effects are less well understood. Like other environmental pollutants, bisphenols are being tested in various experimental models, creating large expression datasets found in open access storage. The meta‐analysis of such datasets is, however, very complicated for various reasons. Here, we developed an integrating statistical and machine‐learning model approach for the meta‐analysis of bisphenol A (BPA) exposure datasets from different mouse tissues. We constructed three joint datasets following three different strategies for dataset integration: in particular, using all common genes from the datasets, uncorrelated, and not co‐expressed genes, respectively.

  • Integration of Fluorescent, NV-Rich Nanodiamond Particles with AFM Cantilevers by Focused Ion Beam for Hybrid Optical and Micromechanical Devices
    • Mateusz Ficek
    • Maciej Głowacki
    • Krzysztof Gajewski
    • Piotr Kunicki
    • Ewelina Gacka
    • Krystian Sycz
    • Mariusz Mrózek
    • Adam M. Wojciechowski
    • Teodor Gotszalk
    • Wojciech Gawlik
    • Robert Bogdanowicz
    2021 Full text Coatings

    In this paper, a novel fabrication technology of atomic force microscopy (AFM) probes integrating cantilever tips with an NV-rich diamond particle is presented. Nanomanipulation techniques combined with the focused electron beam-induced deposition (FEBID) procedure were applied to position the NV-rich diamond particle on an AFM cantilever tip. Ultrasonic treatment of nanodiamond suspension was applied to reduce the size of diamond particles for proper geometry and symmetry. The fabricated AFM probes were tested utilizing measurements of the electrical resistance at highly oriented pyrolytic graphite (HOPG) and compared with a standard AFM cantilever performance. The results showed novel perspectives arising from combining the functionalities of a scanning AFM with optically detected magnetic resonance (ODMR). In particular, it offers enhanced magnetometric sensitivity and the nanometric resolution.

  • Integration of Multi-Source Geospatial Data from GNSS Receivers, Terrestrial Laser Scanners, and Unmanned Aerial Vehicles
    • Paweł Dąbrowski
    • Cezary Specht
    • Mariusz Specht
    • Paweł Burdziakowski
    • Artur Makar
    • Oktawia Lewicka
    2021 Full text CANADIAN JOURNAL OF REMOTE SENSING

    The analysis based on geospatial data from different measurement systems now constitutes a complex numerical and practical enterprise. The dynamic development of modern technologies enables rapid and precise acquisition of such data. Nonetheless, the diversity of reference systems is today one of the main challenges for their correct interpretation. The combined use of the processed measurement results and archival data in paper form constitutes an important direction for the development of this discipline. This issue is visible during the implementation of complex hydrographic and geodetic surveys requiring geospatial integration of results. The publication presents both the theoretical basis and the practical verification of the adopted methodology. The research material comes from the measurement campaign conducted to determine geospatial parameters for the tombolo phenomenon in Sopot. The results of differential GNSS RTK measurements, terrestrial laser scanning, bathymetric survey, photogrammetry, and analog archival bathymetric map were subjected to the integration process. The effectiveness of the presented procedure was confirmed by the obtained error estimators of values not exceeding three centimeters.

  • Inteligentny system decyzyjny jako maszynowa realizacja procesów poznawczych i motywacyjnych
    • Zdzisław Kowalczuk
    • Michał Czubenko
    2021

    W niniejszej książce przedstawiono własny, kompletny i spójny oraz realizowalny model Inteligentnego Systemu Decyzji (ISD), oparty na wiedzy zaczerpniętej z psychologii z elementami motywacyjnymi, w skład którego wchodzi podsystem xEmotion. Wykorzystuje on funkcję i strukturę ludzkich procesów decyzyjnych oraz pewne szczegółowe mechanizmy dedykowane dla obliczeniowych systemów emocji. Model ISD jest w szczególności przeznaczony do realizacji autonomii agenta, zarówno wirtualnego, jak i rzeczywistego, stosowanego w systemach robotycznych. Model Inteligentnego Systemu Decyzyjnego można zatem zaliczać do architektur poznawczych (kognitywnych). Praca przedstawia sformalizowany model procesów poznawczych z uwzględnieniem wybranych humanistycznych teorii motywacji i emocji. Przy czym podstawy psychologiczne dotyczące prezentowanych mechanizmów psychologicznych podano w pracy (M. Czubenko, Z. Kowalczuk: Elementy psychologii w kontekście autonomii robotów, vol. PNT6, PWNT, Gdańsk 2019). Przyjęta struktura pracy w dużej mierze opiera się na podziale procesów poznawczych. Na wstępie przedstawiamy model percepcji agenta (system autonomicznego) wraz z podstawowymi strukturami danych wykorzystywanymi w ścieżce przetwarzania informacji. Następnie wyróżniamy typy pamięci (w kontekście pamięci długotrwałej oraz krótkotrwałej, bądź roboczej). Warto podkreślić, że pamięć sensoryczna ze względu na swoją funkcję buforowania ulokowana jest w systemie percepcji. Po omówieniu struktur pamięciowych, przedstawiamy mechanizmy uwagi, modele motywacyjne z uwzględnieniem wielowymiarowych potrzeb i emocji oraz metody myślenia autonomicznego agenta. Na koniec prezentujemy Czytelnikowi studium badań symulacyjnych, obejmujące częściowe implementacje opracowanego systemu.

  • Interaction Design in Agile IT Projects
    • Marcin Sikorski
    2021 Full text

    In recent years, interactive systems, such as various types of software, online services or mobile applications, have become an integral part of everyday life. Interactive systems and digital services should be easy to use and provide a positive User Experience (UX). For this reason, interaction design has recently emerged as a distinct professional area of information technology (IT). Easy interaction and user experience (UX) are now indispensable elements of IT product quality. Consequently, the User-Centred Design (UCD) approach has been successfully applied to improve IT products' usability and UX. IT projects have undergone radical changes in recent years towards agility. As a result, most of IT solutions nowadays are designed and developed using the agile approach. Regarding to satisfying prospective users’ needs, current IT projects attempt to combine techniques inherited from classical software engineering with novel techniques borrowed from the agile approach. This book presents the impact of the agile approach on User-Centred Design, resulting in gradual adaptation of interaction design methods to agile IT projects. From the perspective of agile project management, the author presents human and social aspects that affect interactive products' quality. Finally, various teamwork management techniques involving prospective users at all stages of an agile IT project are essential for this book.

  • Interactions between polyphenolic antioxidants quercetin and naringenin dictate the distinctive redox-related chemical and biological behaviour of their mixtures
    • Monika Baranowska
    • Zuzanna Koziara
    • Klaudia Suliborska
    • Wojciech Chrzanowski
    • Michael Wormstone
    • Jacek Namieśnik
    • Agnieszka Bartoszek-Pączkowska
    2021 Full text Scientific Reports

    Food synergy concept is suggested to explain observations that isolated antioxidants are less bioactive than real foods containing them. However, mechanisms behind this discrepancy were hardly studied. Here, we demonstrate the profound impact of interactions between two common food flavonoids (individual: aglycones quercetin—Q and naringenin—N− or their glycosides rutin—R and naringin—N+ vs. mixed: QN− and RN+) on their electrochemical properties and redox-related bioactivities. N− and N+ seemed weak antioxidants individually, yet in both chemical and cellular tests (DPPH and CAA, respectively), they increased reducing activity of mixtures synergistically. In-depth measurements (differential pulse voltammetry) pointed to kinetics of oxidation reaction as decisive factor for antioxidant power. In cellular (HT29 cells) tests, the mixtures exhibited properties of a new substance rather than those of components. Pure flavonoids did not influence proliferation; mixtures stimulated cell growth. Individual flavonoids tended to decrease global DNA methylation with growing concentration; this effect was more pronounced for mixtures, but not concentration-dependent. In nutrigenomic studies, expression of gene set affected by QN− differed entirely from common genes modulated by individual components. These results question the current approach of predicting bioactivity of mixtures based on research with isolated antioxidants.

  • Interactions in aqueous solutions of K-peptide and DMSO – spectroscopic and calorimetric studies
    • Julia Godlewska
    • Piotr Bruździak
    2021

    Introduction K-peptide (GILQINSRW) – short 9 amino acid fragment of the hen egg white lysozyme has the ability to form amyloid structures. Dimethyl sulfoxide (DMSO) is an osmolyte which can alter this ability. Our goal was to get an insight into the mechanism of Kpeptide-DMSO interactions in aqueous solutions. Such a knowledge can be helpful to understand processes leading to various neurodegenerative diseases. Methods ATR-FTIR spectroscopy (Thermo Nicolet 8700 equipped with single reflection diamond cell GoldenGate ATR accessory) was used to analyse interactions between solutes in their different proportions: the concentration of DMSO was kept constant in each solution while the peptide concentration varied. In addition, DSC calorimetry (nanoDSC, Thermo) allowed to determine thermal stability of the Kpeptide in aqueous solution with or without the addition of DMSO in the wide temperature range: 10-100 oC. Results The IR spectrum of the K-peptide exhibited a very strong peak usually attributed to beta-sheets. However, its shape was clearly different than in the case of other native or even denatured proteins. We assumed that it was due to the presence of a specific sheets of amyloid structures. The experimental design allowed to observe changes in relatively sharp peaks on ATR-FTIR spectra attributed to chemical bonds of DMSO caused by the presence of the peptide. These changes turned out to be weak, yet DSC calorimetry allowed to conclude that the K-peptide undergoes a few structural changes during the heating process. Depending on the solution composition and protein concentration, the number and exact temperatures of these transitions varied. Acknowledgements This work was funded by the National Science Centre, Poland (grant 2017/26/D/NZ1/00497).

  • Interactions in Ternary Aqueous Solutions of NMA and Osmolytes—PARAFAC Decomposition of FTIR Spectra Series
    • Emilia Kaczkowska
    • Aneta Panuszko
    • Piotr Bruździak
    2021 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Intermolecular interactions in aqueous solutions are crucial for virtually all processes in living cells. ATR-FTIR spectroscopy is a technique that allows changes caused by many types of such interactions to be registered; however, binary solutions are sometimes difficult to solve in these terms, while ternary solutions are even more difficult. Here, we present a method of data pretreatment that facilitates the use of the Parallel Factor Analysis (PARAFAC) decomposition of ternary solution spectra into parts that are easier to analyze. Systems of the NMA–water–osmolyte-type were used to test the method and to elucidate information on the interactions between N-Methylacetamide (NMA, a simple peptide model) with stabilizing (trimethylamine N-oxide, glycine, glycine betaine) and destabilizing osmolytes (n-butylurea and tetramethylurea). Systems that contain stabilizers change their vibrational structure to a lesser extent than those with denaturants. Changes in the latter are strong and can be related to the formation of direct NMA–destabilizer interactions.

  • Interannual Variability of the GNSS Precipitable Water Vapor in the Global Tropics
    • Zofia Baldysz
    • Grzegorz Nykiel
    • Beata Latos
    • Dariusz Baranowski
    • Mariusz Figurski
    2021 Full text Atmosphere

    This paper addresses the subject of inter-annual variability of the tropical precipitable water vapor (PWV) derived from 18 years of global navigation satellite system (GNSS) observations. Non-linear trends of retrieved GNSS PWV were investigated using the singular spectrum analysis (SSA) along with various climate indices. For most of the analyzed stations (~49%) the GNSS PWV anomaly was related to the El Niño Southern Oscillation (ENSO), although its influence on the PWV variability was not homogeneous. The cross-correlations coefficient values estimated between the Multivariate ENSO Index (MEI) and PWV were up to 0.78. A strong cross-correlation was also found for regional climate pattern expressed through CAR, DMI, HAW, NPGO, TNA and TSA indices. A distinct agreement was also found when instead of climate indices, the local sea surface temperature was examined (average correlation 0.60). The SSA method made it also possible to distinguish small-scale phenomena that affect PWV, such as local droughts or wetter rainy seasons. The overall nature of the investigated changes was also verified through linear trend analysis. In general, not a single station was characterized by a negative trend and its weighted mean value, calculated for all stations was equal to 0.08 ± 0.01 mm/year.

  • Interdisciplinarity in Smart Sustainable City education: exploring educational offerings and competencies worldwide
    • Magdalena Ciesielska
    • Nina Rizun
    • Tomasz Janowski
    2021 Full text

    More and more higher education institutions are offering specialized study programs for current and future managers of Smart Sustainable Cities (SSCs). In the process, they try to reconcile the interdisciplinary nature of such studies, covering at least the technical and social aspects of SSC management, with their own traditionally discipline-based organization. However, there is little guidance on how such interdisciplinarity should be introduced. In order to address this gap, this paper identifies 87 SSC-related study programs from around the world and analyzes their disciplinary and interdisciplinary coverage. The analysis classifies programs and competencies, the former using text mining and clustering algorithms, the latter using Bloom’s taxonomy and correlation analysis.

  • Interspecific and intraspecific variation in organochlorine pesticides and polychlorinated biphenyls using non-destructive samples from Pygoscelis penguins
    • Juliana Silva Souza
    • Aneta Pacyna-Kuchta
    • Larissa Schmauder Teixeira da Cunha
    • Erli Schneider Costa
    • Przemyslaw Niedzielski
    • João Paulo Machado Torres
    2021 Full text ENVIRONMENTAL POLLUTION

    As humans are present in Antarctica only for scientific and tourism-related purposes, it is often described as a pristine region. However, studies have identified measurable levels of Persistent Organic Pollutants (POPs), such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), in the Antarctic region. These are highly toxic anthropogenic compounds with tendency to travel long distances and reach remote environments, where they can bioaccumulate in the biota. Penguins are exposed to POPs mainly through their diet, which they partially eliminate via feathers. Species of the genus Pygoscelis occur around Antarctic continent and its surrounding regions, and can act as indicators of contaminants that reach the continent. Here, we report OCP and PCB levels in feathers of male and female penguins of P. adeliae, P. antarcticus and P. papua from King George Island, South Shetland Islands, Antarctica. Interspecific, sex- and body-size-related differences were investigated in the contamination profiles of PCBs and OCPs. Feather samples were collected from adult penguins (n = 41). Quantification of compounds was performed by gas chromatography-tandem mass spectrometry. The three Pygocelis species presented similar contamination profiles, with higher concentrations of dichlorodiphenyltrichloroethane (ΣDDT; 1.56–3.82 ng g−1 dw), lighter PCB congeners (ΣPCB: 11.81–18.65 ng g−1 dw) and HCB (hexachlorobenzene: 1.65–4.06 ng g−1 dw). Amongst the three penguin species, P. antarcticus had lower and P. papua higher concentrations of most of the compounds identified. We found interspecific differences in POP accumulation as well as sex differences in POP concentrations. Our data indicate a small but significant positive correlation between body size and the concentrations of some compounds. Despite the overall low concentrations found, this study increases knowledge of the occurrence of POPs in Antarctic penguins, thereby reinforcing concerns that Antarctica, although remote and perceived to be protected, is not free from the impact of anthropogenic pollutants.

  • Interval Edge Coloring of Bipartite Graphs with Small Vertex Degrees
    • Anna Małafiejska
    • Michał Małafiejski
    • Krzysztof Ocetkiewicz
    • Krzysztof Pastuszak
    2021

    An edge coloring of a graph G is called interval edge coloring if for each v ∈ V(G) the set of colors on edges incident to v forms an interval of integers. A graph G is interval colorable if there is an interval coloring of G. For an interval colorable graph G, by the interval chromatic index of G, denoted by χ'_i(G), we mean the smallest number k such that G is interval colorable with k colors. A bipartite graph G is called (α,β)-biregular if each vertex in one part has degree α and each vertex in the other part has degree β. A graph G is called (α*,β*)-bipartite if G is a subgraph of an (α,β)-biregular graph and the maximum degree in one part is α and the maximum degree in the other part is β. In the paper we study the problem of interval edge colorings of (k*,2*)-bipartite graphs, for k ∈ {3,4,5}, and of (5*,3*)-bipartite graphs. We prove that every (5*,2*)-bipartite graph admits an interval edge coloring using at most 6 colors, which can be found in O(n^{3/2}) time, and we prove that an interval edge 5-coloring of a (5*,2*)-bipartite graph can be found in O(n^{3/2}) time, if it exists. We show that every (4^*,2^*)-bipartite graph admits an interval edge 4-coloring, which can be found in O(n) time. The two following problems of interval edge coloring are known to be NP-complete: 6-coloring of (6,3)-biregular graphs (Asratian and Casselgren (2006)) and 5-coloring of (5*,5*)-bipartite graphs (Giaro (1997)). In the paper we prove NP-completeness of 5-coloring of (5*,3*)-bipartite graphs.

  • Intraday price reaction to filing bankruptcy and restructuring proceedings – the evidence from Poland
    • Błażej Prusak
    • Marcin Potrykus
    2021 Full text

    This chapter presents the results of research on the price reaction of shares listed on the Warsaw Stock Exchange to filing bankruptcy and/or restructuring applications. Event study was adopted as the research method, and it was performed at 10, 5, and 1-minute intervals. It was found that the reaction is rapid, as it takes 1–2 minutes after the information on bankruptcy and restructuring applications was made public. Significantly higher negative above-average rates of return were obtained when information on bankruptcy applications was made public. Moreover, the stock price response was more sudden when the information was made publicly outside the trading session. In general, this confirms that the functioning of the Electronic System for Information Transmission (ESPI) in Poland reduces the asymmetry of information between investors and contributes to an increase of market efficiency. However, the conducted research also showed that there is a time gap of 7 minutes on average on the market between the submission of information about the application and the reaction of investors to such information. It may be used by investors who, using automated trading systems, will take a short position on the relevant assets in advance of traditional investors.

  • Introduction to the special issue on machine learning in acoustics
    • Zoi-Heleni Michalopoulou
    • Peter Gerstoft
    • Bożena Kostek
    • Marie A. Roch
    2021 Full text Journal of the Acoustical Society of America

    When we started our Call for Papers for a Special Issue on “Machine Learning in Acoustics” in the Journal of the Acoustical Society of America, our ambition was to invite papers in which machine learning was applied to all acoustics areas. They were listed, but not limited to, as follows: • Music and synthesis analysis • Music sentiment analysis • Music perception • Intelligent music recognition • Musical source separation • Singing analysis and voice quality evaluation • Expressivity in music • Bioacoustics • Soundscapes • Hearing and hearing aids • Speech, language, and emotion recognition • Speech recognition • Emotion in speech • Speech perception • Expressivity in speech • Intelligent speech processing • Multimedia speech processing • Classification from active acoustics • Acoustic source localisation • Acoustic field prediction in ocean acoustics • Acoustical oceanography

  • Introductory Chapter: Evolution of Sample Preparation
    • Massoud Kaykhaii
    2021

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  • Inverse determination of sliding surface temperature based on measurements by thermocouples with account of their thermal inertia
    • Oleksii Nosko
    • Yurii Tsybrii
    2021 Full text TRIBOLOGY INTERNATIONAL

    This study developed an inverse heat conduction algorithm to determine temperature at a sliding surface taking account of thermocouple thermal inertia. The direct heat conduction problem was solved analytically based on the Laplace integral transform approach. The inverse algorithm was applied to the problem of friction of a brake material against a steel. The experiments were conducted on a pin-on-disc tribometer for three short-time sliding regimes: velocity step, acceleration and deceleration. Temperature in the pin sample was measured by two identical miniature thermocouples installed at different distances from the friction surface. It was found that the two inverse surface temperatures agree well between each other. The inverse algorithm allows predicting the contact temperature measured by infrared thermography with accuracy 5–7%.

  • Inverse Nonlinear Eigenvalue Problem Framework for the Synthesis of Coupled-Resonator Filters With Nonresonant Nodes and Arbitrary Frequency-Variant Reactive Couplings
    • Martyna Mul
    • Adam Lamęcki
    • Roberto Gómez-García
    • Michał Mrozowski
    2021 Full text IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    A novel, general circuit-level description of coupledresonator microwave filters is introduced in this article. Unlike well-established coupling-matrix models based on frequency-invariant couplings or linear frequency-variant couplings (LFVCs), a model with arbitrary reactive frequencyvariant coupling (AFVC) networks is proposed. The engineered formulation is more general than prior-art ones—with the only restriction that the coupling network is a reactive-type twoport circuit—and can be treated as an extension of previous synthesis models since constant or linear couplings are special cases of arbitrary frequency dependence. The suggested model is fully general, which allows for AFVCs with highly nonlinear (even singular) characteristics, loaded or unloaded nonresonating nodes (NRNs), frequency-dependent source–load coupling, multiple frequency-variant cross couplings, and/or multiple dispersive couplings for connecting the source and load to the filter network. The model is accompanied by a powerful synthesis technique that is based on the zeros and poles of the admittance or scattering parameters and the eigenvalues of properly defined eigenproblems. In the most general case, the zeros and poles of the admittance or scattering parameters are related to solutions of nonlinear eigenvalue problems. The synthesis is defined as an inverse nonlinear eigenvalue problem (INEVP) where the matrix is constructed from three sets of eigenvalues. This is accomplished by optimization using an iterative nonlinear least-squares solver with excellent convergence property. Finally, the third- and fifth-order examples of bandpass filter topologies involving AFVCs are shown, and the experimental validation of the proposed theory is presented through the manufacturing and characterization of a microstrip filter prototype with transmission zeros (TZs).

  • Investigating lubricants behaviour in microgravity for vibration damping purposes
    • Szymon Krawczuk
    • Adam Dąbrowski
    2021 Full text

    Vibration is one of the harshest environments an object is exposed to during and after launch into space on a launch vehicle. Such vibrations should be damped to avoid destruction of the spacecraft or its elements. Currently, active and material damping is used. A possibility of using lubrication as the damping factor is suggested by some research. MoS2 is a typical solid lubricant used in space applications. Its properties vary heavily with environmental conditions and have been tested on ground. Recent research proves that dynamic characteristics of other lubricants are significantly affected by microgravity regime. This paper sums up current knowledge and proposes a research for the characterisation of mechanical damping properties of MoS2 in microgravity. For that reason a drop tower and zero-g flight experiments are designed with a cantilever beam (a tuned vibration amplifier-filter). The cases of dry and wet (lubricated) vibrations will be tested. The beam will be triggered by an electromagnet and a set of sensors: accelerometers, strain gauges and capacitive displacement sensors will measure its vibrations. Computer analysis of the results will allow us to determine the damping coefficient of the lubricant in microgravity conditions. Knowledge of this parameter will determine if damping properties of the MoS2 lubrication (useful for tribological reasons) could be applied for damping of vibrations in spacecraft. This could possibly decrease the need for active vibration control and lower costs of future space missions.

  • Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs
    • F. Kazemi
    • Mahmoud Miari
    • Robert Jankowski
    2021 Full text Bulletin of Earthquake Engineering

    An insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel Moment Resisting Frames (MRFs) were considered to investigate the collision effects and to determine modification factors for new and already existing buildings. For this purpose, incremental dynamic analysis was used to assess the seismic limit state capacity of the structures using a developed algorithm in OpenSees software including two near-field record subsets suggested by FEMA-P695. The results of this paper can help engineers to approximately estimate the performance levels of MRFs due to pounding phenomenon. The results confirm that collisions can lead to the changes in performance levels, which are difficult to be considered during the design process. In addition, the results of the analyses illustrate that providing a fluid viscous damper between adjacent reinforced concrete and steel structures can be effective to eliminate the sudden changes in the lateral force during collision. This approach can be successfully used for retrofitting adjacent structures with insufficient in-between separation distances.

  • Investigation into the Effect of Spinel Pigments on the Photostability and Combustion Properties of Ethylene-Norbornene Copolymer
    • Małgorzata Kuśmierek
    • Bolesław Szadkowski
    • Przemysław Rybiński
    • Magdalena Śliwka-Kaszyńska
    • Mirosława Prochoń
    • Bartłomiej Syrek
    • Anna Marzec
    2021 Full text Materials

    Multicolor ethylene-norbornene (EN) composites filled with three different spinel pigments (Cobalt Green-PG50, Zinc Iron Yellow-PY 119, Praseodym Yellow-PY159) were prepared by melt mixing and characterized in terms of their stability under destructive environmental conditions. The EN films were subjected to accelerated aging by ultraviolet (UV) photooxidation for 300 h, 600 h, or 900 h. The mechanical performance of the EN composites was investigated in static and dynamic mechanical tests. The morphologies of the EN samples and their color changes during the aging process were evaluated by scanning electron microscopy (SEM) and spectrophotometric measurements. Fourier transform infrared (FTIR) spectroscopy was applied to determine the amount of carbonyl groups resulting from surface oxidation at different aging times. The effects of the spinel pigments on the thermal stability and combustion properties of the multicolor polymer composites were also assessed, and compared with a sample containing the organic Pigment Yellow 139 (PY139). The results show that the color changes (DE) in the spinel pigments were minor in comparison to those in the organic pigment (PY139) and the reference film. The Zinc Yellow (PY119) pigment was the most effective stabilizer of EN copolymer. Moreover, the spinel pigments had a positive effect on the flame retardancy of the EN composites. Microcombustion tests (MCC) showed that the incorporation of both the spinels and the organic pigment PY139 into the EN matrix reduced the heat release rate (HRR) and total heat release (THR) parameters.

  • Investigation of Acoustic Properties of Poroelastic Asphalt Mixtures in Laboratory and Field Conditions
    • Władysław Gardziejczyk
    • Piotr Jaskuła
    • Jerzy Ejsmont
    • Marek Motylewicz
    • Marcin Stienss
    • Piotr Mioduszewski
    • Paweł Gierasimiuk
    • Maciej Zawadzki
    2021 Full text Materials

    Measures for the improvement of acoustic conditions in the vicinity of roads include the construction of pavement structures with low-noise surfaces with optimal macrotexture and the highest possible sound absorption coefficient. Laboratory evaluation of acoustic properties of a designed asphalt mixture before its placement in the pavement is a good solution. Currently, the most popular method for the determination of the sound absorption coefficient of various construction materials under laboratory conditions is the Kundt’s tube test. Sound absorption coefficient can also be assessed based on field and laboratory measurements performed using a Spectronics ACUPAVE System. Other parameters characterising the acoustic properties of road pavement courses include air void content and water drainability or permeability. The article presents an analysis of results of sound absorption coefficient obtained using a Spectronics ACUPAVE System and water drainability and permeability of poroelastic mixtures obtained both in laboratory and on test sections, in relation to air void content and grading of the mixtures. It was established that poroelastic mixtures containing an aggregate of maximum particle size of 5 mm are characterised by better acoustic properties than mixtures with a maximum aggregate particle size of 8 mm. Changes of crumb rubber aggregate grading and bitumen type (within the tested range of values) as well as the addition of lime have shown no evident influence on the sound absorption coefficient. Noise level values at the speed of 30 km/h according to the CPX method were measured as well. Relationships between sound absorption coefficient, water drainability/permeability, and air void content were determined. The performed analyses confirmed that Spectronics ACUPAVE System may be applied for evaluation of acoustic properties of asphalt mixtures in laboratory conditions, but further research is needed to reduce the uncertainty of the results.

  • Investigation of energy deposition and its optical imaging in polymer gel dosimeters
    • Jakub Czubek
    • Marta Marszewska
    • Brygida Mielewska
    • Marek Maryański
    2021

    This following chapter describes methods for verifying the absorbed dose during radiotherapy. Special attention is paid to the method using polymer-gel dosimeters, the dose reading of which is performed by means of Laser Computed Tomography. The chapter also includes considerations on alternative solutions for dosimetric measurements and various types of radiotherapy and their pros and cons. In addition, both the methods of structural research of these gel dosimeters as well as the principle of operation and parameters of Laser Computed Tomography are considered.

  • Investigation of magnetic order in a new intermetallic compound Nd2PtGe3
    • Leszek Litzbarski
    • Michał Winiarski
    • P. Skokowski
    • Tomasz Klimczuk
    • Bartłomiej Andrzejewski
    2021 Full text JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

    In the present study we report a successful synthesis of the new intermetallic compound Nd2PtGe3 by an arc-melting method. The powder X-ray diffraction analysis indicates that this compound crystallizes in an disordered variant of the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a = 4.2455 Å and c = 4. 1933 Å. The compound exhibits a cluster-glass transition below Tf = 2.9 K, characterized through ac and dc magnetic susceptibility and heat capacity measurements.

  • Investigation of Mechanical and Microstructural Properties of Welded Specimens of AA6061-T6 Alloy with Friction Stir Welding and Parallel Friction Stir Welding Methods
    • Amir Ghiasvand
    • Mohammad M. Yavari
    • Jacek Tomków
    • John W. Grimaldo Guerrero
    • Hasan Kheradmandan
    • Aleksei Dorofeev
    • Shabbir Memon
    • Hesamoddin Aghajani Derazkola
    2021 Full text Materials

    The present study investigates the effect of two parameters of process type and tool offset on tensile, microhardness, and microstructure properties of AA6061-T6 aluminum alloy joints. Three methods of Friction Stir Welding (FSW), Advancing Parallel-Friction Stir Welding (AP-FSW), and Retreating Parallel-Friction Stir Welding (RP-FSW) were used. In addition, four modes of 0.5, 1, 1.5, and 2 mm of tool offset were used in two welding passes in AP-FSW and RP-FSW processes. Based on the results, it was found that the mechanical properties of welded specimens with AP-FSW and RP-FSW techniques experience significant increments compared to FSW specimens. The best mechanical and microstructural properties were observed in the samples welded by RP-FSW, AP-FSW, and FSW methods, respectively. Welded specimens with the RP-FSW technique had better mechanical properties than other specimens due to the concentration of material flow in the weld nugget and proper microstructure refinement. In both AP-FSW and RP-FSW processes, by increasing the tool offset to 1.5 mm, joint efficiency increased significantly. The highest weld strength was found for welded specimens by RP-FSW and AP-FSW processes with a 1.5 mm tool offset. The peak sample of the RP-FSW process (1.5 mm offset) had the closest mechanical properties to the base metal, in which the Yield Stress (YS), ultimate tensile strength (UTS), and elongation percentage (E%) were 76.4%, 86.5%, and 70% of base metal, respectively. In the welding area, RP-FSW specimens had smaller average grain size and higher hardness values than AP-FSW specimens.

  • Investigation of tetrabutylammonium bromide-glycerol-based deep eutectic solvents and their mixtures with water by spectroscopic techniques
    • Renáta Chromá
    • Mária Vilková
    • Ivan Shepa
    • Patrycja Makoś-Chełstowska
    • Vasil Andruch
    2021 Full text JOURNAL OF MOLECULAR LIQUIDS

    Deep eutectic solvents (DES) are formed by an acceptor and a donor of hydrogen bonds. They are generally considered as a possible alternative to hazardous organic solvents in various fields. Very recently they have also appeared in analytical chemistry, used mainly for the separation of analytes before instrumental quantification. For the development of new extraction procedures, it is important, among other things, to understand the mechanism of the extraction process itself. In this study we present NMR, IR and Raman spectroscopy studies of TBAB-Gly-based DESs at various HBA:HBD molar ratios for the neat DES as well as the DES mixed with various amounts of added water to better understand the mechanism of DES formation, intermolecular interactions in DES and the interaction of the DES with water, which have not yet been studied in detail. The obtained results indicate that hydrogen bonds between TBAB and Gly exist in the DESs at all molar ratios (1:2; 1:3; 1:4). A small amount of water added to the DES structure provides the establishment of an H-bond network, which does not weaken the existing H-bonds between the HBA and HBD, thus creating a stable supramolecular structure. However, further increasing of water amount provide to weakened of hydrogen bonds between TBAB and Gly.

  • Investigation of the 0.4C-35Cr-45Ni-Nb Alloy after Service in High-Temperature Steam and Hydrocarbons Environment
    • Juliusz Orlikowski
    • Michał Szociński
    • Janusz Zygmuntowicz
    • Gabriel Gajewski
    • Wojciech Filipkowski
    • Kazimierz Darowicki
    2021 Full text Materials

    The paper presents the results of investigation of the 0.4C-35Cr-45Ni-Nb alloy, which operated in the cracked hydrocarbon feeds and dilution steam at 1125 C. The material originated from the pyrolytic furnace coil tubes, of which internal walls were in contact with the aforementioned medium, whereas the external walls were in contact with the flue gases. The examination included metallographic and mechanical tests on the material after service exposure, the results of which were compared with the ones obtained for the as-received non-exposed specimens. The metallographic tests revealed changes in the alloy’s structure manifested by formation of significant amount of the carbides due to carburization of the alloy from the steam and cracked hydrocarbon feeds side. The central and external parts of the alloy samples (having no contact with the process medium) underwent substantial degradation but within a relatively narrow zone of the material. The investigations of hydrogen and methane content in the alloy showed a high amount of these gases, resulting from high-temperature corrosion in steam environment. The mechanical tests demonstrated clear shortening of the plastic deformation range of the alloy due to penetration of the gases and formation of the carbides inside the material’s structure. A low level of corrosion and no creep mechanism were detected.

  • Investigation of Wood Flour Size, Aspect Ratios, and Injection Molding Temperature on Mechanical Properties of Wood Flour/Polyethylene Composites
    • M. E. Golmakani
    • Tomasz Wiczenbach
    • Mohammad Malikan
    • Reza Aliakbari
    • Victor Eremeev
    2021 Full text Materials

    In the present research, wood flour reinforced polyethylene polymer composites with a coupling agent were prepared by injection molding. The effects of wood flour size, aspect ratios, and mold injection temperature on the composites’ mechanical properties were investigated. For the preparation of the polymer composites, five different formulations were created. The mechanical properties including tensile strength and the modulus, flexural strength and the modulus, and impact energy were measured. To investigate the changes in the properties resulting from different compositions, mechanical static and impact testing was performed. The obtained results indicate that by reducing the flour size, the tensile strength and modulus, flexural strength, and impact energy were reduced. In contrast, the flexural modulus increased. Furthermore, with the increment of injection molding temperature, the tensile strength and the modulus and the impact energy of the specimens were reduced. On the other hand, the flexural strength and the modulus increased. Thus, an optimized amount of injection molding temperature can provide improvements in the mechanical properties of the composite.

  • Investigation on air quality of specific indoor environments—spa salons located in Gdynia, Poland
    • Klaudia Pytel
    • Renata Marcinkowska
    • Bożena Zabiegała
    2021 Full text ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    Due to excessive application of essential oils and scented products in spa salons during aromatherapy and massage sessions, the elevated concentration of total volatile organic compounds (TVOCs), particularly terpenes, which are known as secondary organic aerosol (SOA) precursors, is expected there. This study was aimed at determination of VOCs with a particular regard to terpenes in air samples collected in selected spa salons located in Northern Poland. Active air sampling was conducted before and after treatments. Samples were analyzed with the use of thermal desorption gas chromatography coupled with flameionization detector (TD-GC-FID) and mass spectrometer (TD-GC-MS). Obtained results allowed to characterize chemical composition of indoor air of spa salons and also to relate the dependence between applied essential oil and indoor air chemical composition. It has been proved that (i) spa salons are characterized by TVOC concentrations exceeding recommended values of 300–400 μg m−3 in most of examined cases, reaching up to several thousand of micrograms per cubic meter, (ii) TVOC concentration is strictly related to salon characteristics and carried out treatments, (iii) terpenes constitute a significant part of TVOCs present in spa indoor air, from 22 up to 86%, (iv) most commonly investigated terpenes in the literature (D-limonene, αpinene, camphene, and linalool) were also determined at the highest concentration levels in this study and (v) VOC chemical composition is strictly dependent on the type of applied essential oils. On the basis of obtained results, it may be stated that extensive application of essential oils rich in terpenes can significantly alter indoor air chemistry of spa salons, thereby influencing health and well-being of employees working there.

  • INVESTIGATIONS OF THE EMISSION CHARACTERISTICS OF A DUAL-FUEL GAS TURBINE COMBUSTION CHAMBER OPERATING SIMULTANEOUSLY ON LIQUID AND GASEOUS FUELS
    • Serhiy Serbin
    • Badri Diasamidze
    • Viktor Gorbov
    • Jerzy Kowalski
    2021 Full text Polish Maritime Research

    T his study is dedicated to investigations of the working process in a dual-fuel low-emission combustion chamber for a floating vessel’s gas turbine. As the object of the research, a low-emission gas turbine combustion chamber with partial premixing of fuel and air inside the outer and inner radial-axial swirls was chosen. The method of the research is based on the numerical solution of the system of differential equations which represent the physical process of mass and energy conservation and transformations and species transport for a multi-component chemically reactive turbulent system, considering nitrogen oxides formation and a discrete ordinates model of radiation. The chemistry kinetics is presented by the 6-step mechanism of combustion. Seven fuel supply operating modes, varying from 100% gaseous fuel to 100% liquid fuel, have been analysed. This analysis has revealed the possibility of the application of computational fluid dynamics for problems of dual-fuel combustion chambers for the design of a floating vessel’s gas turbine. Moreover, the study has shown the possibility of working in different transitional gaseous and liquid fuel supply modes, as they satisfy modern ecological requirements. The dependencies of the averaged temperature, NO, and CO concentrations along the length of the low-emission gas turbine combustion chamber for different cases of fuel supply are presented. Depending on the different operating modes, the calculated emission of nitrogen oxides NO and carbon monoxide CO at the outlet cross-section of a flame tube are different, but, they lie in the ranges of 31‒50 and 23‒24 mg/nm3 on the peak of 100% liquid fuel supply mode. At operating modes where a gaseous fuel supply prevails, nitrogen oxide NO and carbon monoxide CO emissions lie in the ranges of 1.2‒4.0 and 0.04‒18 mg/nm3 respectively.

  • Investigations on fracture in reinforced concrete beams in 3-point bending using continuous micro-CT scanning
    • Łukasz Skarżyński
    • Andrzej Tejchman-Konarzewski
    2021 Full text CONSTRUCTION AND BUILDING MATERIALS

    This study explores a fracture process in rectangular reinforced concrete (RC) beams subjected to quasi-static three-point bending. RC beams were short and long with included longitudinal reinforcement in the form of a steel or basalt bar. The ratio of the shear span to the effective depth was 1.5 and 0.75. The focus was on the load–deflection diagram and crack formation. Three-dimensional (3D) analyses of the size and distribution of pores and cracks were carried out with an X-ray micro-computed tomography system SkyScan 1173 of high resolution that is a very valuable non-destructive tool for studying a 3D material interior. The tomography system was connected with a quasi-static loading machine ISTRON 5569 to continuously follow fracture changes without loading breaks. The beams failed in shear due to a diagonal shear crack that was steeper with basalt reinforcement. The shear strength and flexural strength of RC beams with steel reinforcement were higher by about 10% than of RC beams with basalt reinforcement. The deflection corresponding to the maximum load of RC beams was higher by about 20–25% in RC beams with basalt reinforcement due to its lower basalt modulus of elasticity. The final volume of cracks in beams reinforced with basalt bars was higher by about 9–20% than in concrete beams reinforced with steel bars due to a higher beam deflection whereas the maximum crack width in concrete beams reinforced with basalt bars was higher by about 20–40% than in concrete beams reinforced with steel bars. The critical shear crack in RC beams with basalt reinforcement was wider by about 20–40% and steeper by about 10–45% as compared to concrete beams with steel reinforcement. The relationship between the crack volume and beam deflection was bi-linear. Both, aggregate breakage and crack branching occurred during beam bending.

  • Ion Chromatography with Pulsed Amperometric Detection for Determining Cyanide in Urine and Meconium Samples
    • Ewa Jaszczak-Wilke
    • Krystyna Kozioł
    • Bogumiła Kiełbratowska
    • Żaneta Polkowska
    2021 Full text MOLECULES

    The parents’ addictions and eating habits have a significant influence on the child’s growth. The first stool of a newborn baby provides a large amount of information about xenobiotics transmitted by the mother’s body. The analytical technique used in the study is ion chromatography with pulsed amperometric detection (IC-PAD). The biological samples, which were obtained from women staying in a maternity ward and their partners, revealed cyanide concentrations in urine samples spanning 1.30–25.3 g L1. Meanwhile, the results of the meconium samples were in the range of 1.54 g L1 to 24.9 g L1. Under the optimized chromatographic conditions, the IC-PAD system exhibited satisfactory repeatability (R < 3%, n = 3) and good linearity in the range of 1–100 g L1. Thus, it proved to be an effective tool for monitoring trace cyanide concentration in a series of human body fluid matrices, including meconium. Based on the literature review, this is the first application of the IC-PAD analytical technique for the determination of cyanide ions in meconium samples.

  • Ionic liquids in extraction techniques: Determination of pesticides in food and environmental samples
    • Karolina Delińska
    • Kateryna Yavir
    • Adam Kloskowski
    2021 TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    The intensive use of pesticides in agricultural practices has promoted the appearance of environmentaland public health problems. Due to that, scientists face challenges with developing simple, fast, sensitive,selective, and low-cost methods dedicated to determining pesticide residues in food and environmentalsamples. Following thefifth principle of Green Analytical Chemistry, chemists are searching for greeneralternatives for toxic organic solvents, thus, implementing the ionic liquids (ILs) to extraction techniques.ILs also contribute to improving the analytical methodologies, e.g., sensitivity, selectivity, and accuracy. Adeeper understanding of the nature of newly developed IL-s based extraction solutions and the impact oftheir investigation on analytical parameters towards the determination of pesticides is crucial forensuring their successful use as potential sorption media for specific purposes. This review presents athorough discussion of currently popular ILs-based extraction techniques dedicated to determiningpesticide residues in food and environmental samples, and highlights the current applications inmicroextraction technique.

  • Ionogel sorbent coatings for determining organophosphorus and pyrethroid insecticides in water and fresh juice samples by headspace-solid phase microextraction
    • Kateryna Yavir
    • Adam Kloskowski
    2021 JOURNAL OF FOOD COMPOSITION AND ANALYSIS

    The sol–gel method yielded three different ionogel sorbent coatings that were obtained based on a silica material containing ionic liquids (ILs) immobilized in its pores. Two ILs, triethylsulfonium bis(trifluoromethylsulfonyl) imide [Set3][TFSI] and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide [C4C1Pip][TFSI], as well as their equimolar mixture [Set3/C4C1Pip], were used to obtain ionogel fibers. The developed sorbents were applied to extract six different insecticides from liquid samples. The crucial extraction parameters of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography with flame ionization detection (GC-FID) method were optimized with a central composite design. The ionogel fibers demonstrated higher selectivity for extracting the analyzed insecticides compared with commercially available fibers. The calculated values of the enrichment factor were in the ranges of 41,400–106,100 for [Set3], 110,600–170,500 for [C4C1Pip], and 76,800–121,100 for [Set3/C4C1Pip]. The [Set3/C4C1Pip] ionogel fiber, demonstrated the highest selectivity for extraction the insecticides. Regarding this coating, the limit of detection in the range of 0.02–0.95 μg L 1, coefficient of determination, which were <0.9690, and a 2.1 %–6.5 % repeatability of the method were achieved. Finally, the obtained ionogel fibers were utilized to determine insecticides in fresh apple and carrot juices.