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  • Tangible and intangible economic impact of hosting mega sporting events
    • Krystian Zawadzki
    2020

    Due to the fact that the impetus for the creation of this paper was inaccuracies in the results of research relating to the economic effects caused by the organisation of mega sporting events, an analysis of the impact of 1988-2008 mega sporting events on host economies was conducted. The research shows that in selected areas of the economy, sporting events can be identified, with occasional positive (SOG) and negative (WOG) economic effects, both nationally and regionally.

  • Tax Evasion, Tax Morale, and Trade Regulations: Company-Level Evidence from Poland
    • Dagmara Nikulin
    2020 Pełny tekst Entrepreneurial Business and Economics Review

    Objective: To investigate the determinants of the phenomenon of evading taxes among polish entrepreneurs. In particular, I examine such factors as tax administration satisfaction, tax morale, tax burden, and the influence of trade regulations. Research Design & Methods: A survey study conducted in 2017 in Poland among 454 enterprises. I used the zero-inflated negative binomial modelling technique to examine the impact of factors on the probability and extent of tax evasion. I also checked the robustness of the obtained results. Findings: I report low tax morale of company managers, low level of satisfaction of tax administration, and tightness of trade regulations as important factors that impact the probability of tax evasion. Moreover, tax morale plays an important role in explaining the extent of underreporting income. I report no significant impact of tax burden on the probability to evade taxes and the magnitude of evasion. Implications & Recommendations: Tax burden should not be considered as predominant in explaining tax evasion inclinations. More social aspects, like the perceived quality of governance, the level of trade regulations, and tax morale, become increasingly important in affecting tax evasion attitudes. Contribution & Value Added: I offer empirical evidence on the determinants of tax evasion. To that end, I utilise a new econometric approach and own primary data.

  • Taxonomy of Schemes for Resilient Routing
    • Ivan Ganchev
    • Jacek Rak
    • Tibor Cinkler
    • Máirtín O’droma
    2020

    This chapter provides a taxonomy of schemes for resilient routing followed by a discussion of their application to contemporary architectures of communication networks. In particular, a general classification of schemes for resilient routing is first presented followed by a description of the reference schemes for IP networks. The chapter in its later part focuses on the representative techniques of resilient routing for a multi-domain and multi-layer network scenarios followed by conclusions also referring to the applicability of the resilient routing schemes in disaster scenarios.

  • Teaching architectural history through virtual reality
    • Szymon Kowalski
    • Piotr Samól
    • Jakub Szczepański
    • Witold Dłubakowski
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    The impact of implementing 3D models and virtual reality in teaching the theory of architecture and architectural history is the theme of this article. Virtual reality and easy-to-use 3D tools allow a whole historic object to be visualised. As a result, there is social and economic pressure to modernise present educational methods using this technology. Therefore, the authors have focused their research on an issue of significance today: how the newest digital technologies might influence the development of students’ technical skills and their abilities for logical thinking.

  • Team Roles and Team Performance in Small Virtual Software Teams
    • Beata Krawczyk-Bryłka
    2020 ZARZĄDZANIE ZASOBAMI LUDZKIMI

    The article presents the results of research on the composition of team roles conducted in 24 student software teams. An adaptation of M. Belbin’s model by B. Kożusznik was used. The model of team balance according to Belbin and Haaf is presented and correlations between team balance and team performance are analysed. Team performance is measured at three levels: result, satisfaction and team climate. The selected constellation of team roles (such as Shaper and Plant, Implementer and Monitor-Evaluator) were analysed in the context of software team performance. The level of team virtualisation was also taken into account.

  • Technical and Economic Analysis of the Implementation of Selected Variants of Road Investment
    • Marcin Szczepański
    • Beata Grzyl
    2020 Pełny tekst Buildings

    The aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to indicate an effective solution that, taking into account technical modifications of the road system elements, will ensure the functionality of the road system to the highest degree and significantly reduce the number of road incidents. To indicate the optimal solution, quantitative data (cost and duration of activities for three options) and qualitative data (determined based on the own experience and knowledge of road industry experts) is analyzed. The authors refer to many criteria of various natures (e.g., economic, technical, functional, environmental, social), which allow for comprehensive consideration of the current requirements of road users and changing circumstances, among others a steady increase in the number of vehicles and growing social expectations in terms of road parameters. Considering the presented analyses and arguments, the authors recommend option 1 as optimal. This is the most expensive solution among those analyzed and with the longest implementation time, however, taking into account the long-term prognosis of the direction and scope of changes to the existing standards and requirements for road infrastructure, it can be stated that option 1 meets them to the highest degree, and also has the greatest potential. The envisaged solution ensures high standards of the quality of road infrastructure use in terms of functionality, capacity, technical parameters, as well as the safety of traffic participants related to the smoothness of the journey, reduction of the number of collisions and accidents.

  • Techno‐economic evaluation of a natural deep eutectic solvent‐based biorefinery: Exploring different design scenarios
    • Adepu K. Kumar
    • Shaishav Sharma
    • Gaurav Dixit
    • Ekta Shah
    • Aesha Patel
    • Grzegorz Boczkaj
    2020 Biofuels Bioproducts & Biorefining-Biofpr

    This paper presents a comprehensive techno‐economic evaluation of an integrated natural deep eutectic solvent (NADES)‐based biorefinery – a 1 ton day−1 capacity design plant. The key parameters include payback period, net present value (NPV), and internal rate of return (IRR). These were compared with the parameters of conventional biorefineries. The ‘n th plant’ results clearly revealed that the single product‐based biorefinery is not a sustainable approach. Hence, value‐added products viz ., cellulose, lignin, xylan, silica, etc ., play a vital role in the cost‐effectiveness of bio‐based biorefineries. Based on ‘base‐case’ experimental results, a pilot‐scale plant design scenario is most feasible, with a NPV of 1.4 million USD, >100% IRR, and a payback period of <2 years. Sensitivity analysis revealed that lignin has the greatest impact on revenue. This report proves that multi‐product biorefineries provide better sustainability. The concepts of solvent recycling and reuse, and key challenges to the commercialization of this design approach, were also discussed. The application of NADES in biorefineries, has several advantages, making the implementation of NADES a key feature for increased sustainability in this industry.

  • Technologia wytwarzania opakowań PET dla produktów wrażliwych
    • Waldemar Karaszewski
    2020 Żródło. Wody i napoje butelkowane

    W artykule przedstawiono nowoczesne, liniowe maszyny rozdmuchowe przeznaczone do wytwarzania opakowań (butelek) PET metodą rozdmuchu z preform. Opisano systemy umożliwiające zmniejszenie zużycia energii elektrycznej niezbędnej do wytworzenia jednego opakowania PET.

  • Technological and Media Platforms: Redefinition of Meanings as Symbolic Power over the Discourse
    • Jan Kreft
    2020 Pełny tekst

    Redefining the meanings of such social terms as “likes” and “friends” on Facebook is a popular practice. In terms of consistency, the (auto)-redefinition of the term “platform” is itself particularly important from a media management perspective. The article proposes to consider the redefinition of meanings as a form of wielding non-transparent power over discourse. From this perspective, redefining a meaning is a form of holding symbolic power, i.e. imposing meaning and thus concealing the system of powers existing at its base. The article is theoretical in its nature and complements the framework that explains how, by redefining and imposing new meanings, media and technology platform managing companies can use a new interpretation of the relationship between the organization and the user and other entities. The aim of the article is to stimulate research on the redefinition of meanings as a form of media management by providing a new theoretical perspective. Hermeneutics, that provides a framework for looking at the redefinition of meanings, was taken as the theoretical perspective.

  • Technological capability dynamics through cluster organizations
    • Anna Lis
    • Małgorzata Rozkwitalska
    2020 Pełny tekst Baltic Journal of Management

    Purpose – The purpose of the paper is to portrait how members of cluster organizations (COs) perceive the role of COs in enabling them to accumulate technological capability (TC) significant for their innovation. Design/methodology/approach – The authors report the findings from their qualitative study based on an analysis of four COs. The organizational inertia and absorptive capacity (AC) theories are the theoretical underpinning of the research. Findings – The study shows that the dynamics of TC of the cluster companies included in the study sample relates to their initial level of TC and cluster cooperation. The companies with relatively low initial TC increase it through COs if the clusters offer comparatively high benefits. On the other hand, those COs’ members that present relatively high initial TC advance it, provided that the external knowledge and other benefits they can absorb in their clusters are suited to their technological trajectories. Research implications/limitations – The research is preliminary in nature and portrays how firms with different levels of TC cooperate within COs and how this cooperation translates into TC improvements. The findings add to the state-of-the-art knowledge on the link between TC and AC of companies involved in COs by depicting the role of COs in providing knowledge and other cluster benefits that help cluster companies to accumulate TC and improve their AC. Nevertheless, the applied methodology does not allow the authors to generalize the findings. Practical implications – The coordinators of COs should skillfully shape the levels of cluster cooperation, matching them to the desired level of the cluster companies. They should create smaller subgroups composed of companies with similar TC, which may translate into its higher dynamics. Originality/value – The knowledge about the role of COs in providing cluster benefits that help cluster companies to accumulate TC and improve their AC is still insufficient. The study shed new light on the key role of the levels of cluster cooperation and the types of commitment related to them (i.e. technological effort), which may be a matter of importance in the dynamics of TC accumulation.

  • Tecnología y Democracia ¿Un amor de pandemia o una relación estable?
    • Robert Krimmer
    • David Duenas Cid
    2020

    Prologar una obra como esta es un privilegio y una responsabilidad. Es un privilegio en tanto que da paso a un seguido de contribuciones de gran calado y relevancia académica que contribuyen a la mejora del conocimiento existente acerca de la relación entre la tecnología y el funcionamiento de la democracia. Es una responsabilidad en el sentido que debe poner sobre la mesa algunas de las cuestiones abiertas de la disciplina y como se engarzan con la motivación que reside detrás de esta propuesta editorial, en un momento en que es más necesaria que nunca. Sabiendo de la complejidad de este cometido, queremos arrojar algunas ideas que sirvan para enmarcar la relación que existe entre los dos conceptos en liza en: tecnología, democracia y su (a nuestro entender, necesaria) interrelación.

  • Telomere uncapping by common oxidative guanine lesions: Insights from atomistic models
    • Miłosz Wieczór
    • Jacek Czub
    2020 FREE RADICAL BIOLOGY AND MEDICINE

    Oxidative damage to DNA is widely known to contribute to aging and disease. This relationship has been extensively studied for telomeres – structures that cap chromosome ends – due to their role in cell proliferation and senescence, and exceptional susceptibility to oxidation. Indeed, the repetitive telomeric DNA sequence contains the 5′-GGG-3′ motif that has the lowest ionization potential of all trinucleotides. Accordingly, experiments consistently show that telomeric oxidative lesions are more abundant and persistent than elsewhere in the genome. This led to a hypothesis that telomeres act as sensors of prolonged oxidative stress and prevent carcinogenesis, as disruption of telomeric integrity triggers senescence or apoptosis. Here, we use atomistic alchemical Molecular Dynamics simulations to perform a combinatorial assessment of changes in DNA binding affinity of telomeric proteins induced by oxidative guanine lesions. We rank lesions by their effect on telomere integrity, as well as telomeric proteins by their sensitivity to DNA oxidation. While the binding of most proteins is abolished by DNA oxidation, HOT1 emerges as a notable exception, suggesting its potential role in sensing of oxidative damage. Through statistical analysis and free energy decomposition, we also identify common trends in structural responses of protein-DNA complexes that contribute to decreased binding affinity.

  • Temperature distribution of supercapacitors prepared by various technologies
    • Stanisław Galla
    • Arkadiusz Szewczyk
    • Janusz Smulko
    • Łukasz Lentka
    2020 Pełny tekst Materials Today: Proceedings

    Supercapacitors, also known by different names such as electrostatic double-layer capacitors (EDLCs) or ultra-capacitors, are electrical storage devices still in development. These devices require fast and reliable methods of assessing their state-of-health. Thermographic imaging is a method which can be applied with this aim due to its popularity, and the high negative impact of overheating on a supercapacitor’s parameters. Moreover, thermographic imaging can be easily used to identify any hot spots, present during charging and discharging while in use. These devices are comprised of porous carbon electrodes and an electrolyte, and during the charging/discharging process, extensive heat may be generated and dissipated there. We have observed temperature fluctuations and were able to identify the inhomogeneity of the tested structures. The electrical parameters (capacitance C and equivalent serial resistance ESR) were measured to determine deterioration of the specimen as requested by the industrial standard. X-ray examination of the samples was performed to identify the shape of the applied metal charge collectors. Both techniques indicated areas where eventual overheating took place due to their electrodes’ shape, suggesting their further optimisation. The proposed method is much less accurate than the calorimetric methods, determining energy flows, but is still sufficient to identify problems with heat dissipation in the developed specimens. Finally, some conclusions about the ability to apply this method in practice to monitor supercapacitors during use were presented.

  • Termoplastyczne elastomery poli(estro-uretanowe) otrzymywane z udziałem bio-glikolu poddane dwukrotnemu przetwórstwu
    • Ewa Głowińska
    • Joanna Niesiobędzka
    • Arkadiusz Cybart
    • Janusz Datta
    2020 Pełny tekst Elastomery

    Recykling materiałów polimerowych w istotny sposób wpływa na zmniejszenie ilości odpadów z tworzyw sztucznych składowanych na wysypiskach śmieci. Jedną z metod recyklingu jest recykling mechaniczny, stosowany szczególnie w przypadku materiałów o właściwościach termoplastycznych. W pracy zbadano wpływ dwukrotnego przetwórstwa termoplastycznych elastomerów poli(estro-uretanowych), TPU, otrzymywanych z udziałem bio-glikolu na strukturę chemiczną, właściwości termiczne, przetwórcze i mechaniczne. W efekcie umożliwi to prognozowanie ilości cykli przetwórczych oraz określenie zmian, jakie mogą zajść w strukturze i właściwościach. Poli(estro-uretany) otrzymano metodą prepolimerową. Zsyntezowane materiały po uprzednim rozdrobnieniu poddano dwukrotnie procesom przetwórczym za pomocą mieszalnika typu Brabender. Próbki do badań formowano przy użyciu prasy hydraulicznej. Strukturę chemiczną otrzymanych materiałów określono za pomocą spektroskopii w podczerwieni FTIR. Zbadano wskaźnik szybkości płynięcia (MFI), właściwości termiczne i mechaniczne, twardość oraz gęstość. Na podstawie przeprowadzonych badań wykazano wpływ ponownego przetwórstwa na zmiany w strukturze oraz badanych właściwościach poli(estro-uretanów). Stwierdzono, że otrzymane materiały mogą być ponownie wykorzystane do produkcji nowych wyrobów, niemniej jednak zmianie ulegną ich warunki przetwórcze. Słowa kluczowe: termoplastyczne elastomery poli(estro-uretanowe), wskaźnik szybkości płynięcia, właściwości mechaniczne, właściwości termiczne, przetwórstwo.

  • Test Stand for Multi-option Stretching of Soft Tissues
    • Grzegorz Rotta
    • Szymon Grymek
    2020

    The paper presents the genesis of the design and possibilities of the test stand for stretching soft tissues as well as examples of tests carried out on this device.

  • Test Stand for Multi-option Stretching of Soft Tissues
    • Grzegorz Rotta
    • Szymon Grymek
    2020

    The paper presents the genesis of the design and possibilities of the test stand for stretching soft tissues as well as examples of tests carried out on this device.

  • Testing sensitivity of A-type residual current devices to earth fault currents with harmonics
    • Stanisław Czapp
    2020 Pełny tekst SENSORS

    In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.

  • Testing Stability of Digital Filters Using Multimodal Particle Swarm Optimization with Phase Analysis
    • Damian Trofimowicz
    • Tomasz Stefański
    2020

    In this paper, a novel meta-heuristic method for evaluation of digital filter stability is presented. The proposed method is very general because it allows one to evaluate stability of systems whose characteristic equations are not based on polynomials. The method combines an efficient evolutionary algorithm represented by the particle swarm optimization and the phase analysis of a complex function in the characteristic equation. The method generates randomly distributed particles (i.e., a swarm) within the unit circle on the complex plane and extracts the phase quadrant of function value in position of each particle. By determining the function phase quadrants, regions of immediate vicinity of unstable zeros, called candidate regions, are detected. In these regions, both real and imaginary parts of the complex function change signs. Then, the candidate regions are explored by subsequently generated swarms. When sizes of the candidate regions are reduced to a value of assumed accuracy, then the occurrence of unstable zero is verified with the use of discrete Cauchy's argument principle. The algorithm is evaluated in four benchmarks for integer- and fractional-order digital filters and systems. The numerical results show that the algorithm is able to evaluate the stability of digital filters very fast even with a small number of particles in subsequent swarms. However, the multimodal particle swarm optimization with phase analysis may not be computationally efficient in stability tests of systems with complicated phase portraits.

  • Testing the Positioning Accuracy of GNSS Solutions during the Tramway Track Mobile Satellite Measurements in Diverse Urban Signal Reception Conditions
    • Mariusz Specht
    • Cezary Specht
    • Andrzej Wilk
    • Władysław Koc
    • Leszek Smolarek
    • Krzysztof Czaplewski
    • Krzysztof Karwowski
    • Paweł S. Dąbrowski
    • Jacek Skibicki
    • Piotr Chrostowski
    • Jacek Szmagliński
    • Sławomir Grulkowski
    • Sławomir Judek
    2020 Pełny tekst ENERGIES

    Mobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which effectively enables the combining of design and construction works, as well as their implementation by engineering teams of diverse specialties. In the article, we attempted to assess the impact of using three types of work mode for a GNSS geodetic network [Global Positioning System (GPS), GPS/Global Navigation Satellite System (GLONASS) and GPS/GLONASS/Galileo] on positioning availability at three accuracy levels: 1 cm, 3 cm and 10 cm. This paper presents a mathematical model that enables the calculation of positioning availability at these levels. This model was also applied to the results of the measurement campaign performed by five GNSS geodetic receivers, made by a leading company in the field. Measurements with simultaneous position recording and accuracy assessment were taken separately on the same route for three types of receiver settings: GPS, GPS/GLONASS and GPS/GLONASS/Galileo in an urban area typical of a medium-sized city. The study has shown that applying a two-system solution (GPS/GLONASS) considerably increases the availability of high-precision coordinates compared to a single-system solution (GPS), whereas the measurements with three systems (GPS/GLONASS/Galileo) negligibly increase the availability compared to a two-system solution (GPS/GLONASS).

  • Tests of bond between concrete and steel bars – literature background and program of own research
    • Marcin Burdziński
    • Maciej Niedostatkiewicz
    • Patryk Ziółkowski
    2020 Pełny tekst Budownictwo i Architektura

    This article deals with the issue of the bond between concrete and reinforcement. The bond is crucial for reinforced concrete elements because it is possible to transfer forces (stresses) from concrete to the reinforcement. Basic information related to the cooperation of concrete and rebars was recalled in the article. Selected issues concerning theoretical and numerical analysis as well as experiments of the bond phenomenon were presented. The article also proposes its own concept of experimental studies on the bond on two types of specimens: so-called short specimen and large specimen that will be subjected to pull-out tests. The described concept is ultimately to form the basis for creating a numerical model, enabling the simulation of bond in various reinforced concrete elements, calibrated based on the results of experimental studies.

  • Texture Features for the Detection of Playback Attacks: Towards a Robust Solution
    • Maciej Smiatacz
    2020 Advances in Intelligent Systems and Computing

    This paper describes the new version of a method that is capable of protecting automatic speaker verification (ASV) systems from playback attacks. The presented approach uses computer vision techniques, such as the texture feature extraction based on Local Ternary Patterns (LTP), to identify spoofed recordings. Our goal is to make the algorithm independent from the contents of the training set as much as possible; we look for the descriptors that would allow the method to detect attacks performed in an environment entirely different from the training one and with the use of the equipment that differs considerably from the devices that captured the training samples. The final form of our method, based on the previously presented proof of concept, performs significantly better than the reference Textrogram algorithm.

  • The abrasive wear resistance of coatings manufactured on high-strength low-alloy (HSLA) offshore steel in wet welding conditions
    • Jacek Tomków
    • Artur Czupryński
    • Dariusz Fydrych
    2020 Pełny tekst Coatings

    Some marine and offshore structure elements exploited in the water cannot be brought to the surface of the water as this will generate high costs, and for this reason, they require in-situ repairs. One of the repair techniques used in underwater pad welding conditions is a wet welding method. This paper presents an investigation of the abrasive wear resistance of coatings made in wet welding conditions with the use of two grades of covered electrodes—an electrode for underwater welding and a commercial general use electrode. Both electrodes were also used for manufacturing coatings in the air, which has been also tested. The Vickers HV10 hardness measurements are performed to demonstrate the correlation in abrasive wear resistance and the hardness of each specimen. The microscopic testing was performed. For both filler materials, the coatings prepared in a water environment are characterized by higher resistance to metal–mineral abrasion than coatings prepared in an air environment—0.61 vs. 0.44 for commercial usage electrode and 0.67 vs. 0.60 for underwater welding. We also proved that in the water, the abrasive wear was greater for specimens welded by the general use electrode, which results in a higher hardness of the layer surface. In the air welding conditions, the layer welded by the electrode for use in the water was characterized by a lower hardness and higher resistance to metal–mineral abrasion. The microstructure of the prepared layers is different for both the environment and both electrodes, which results in abrasive wear resistance.

  • The Analysis of Working Parameters Decrease in Photovoltaic Modules as a Result of Dust Deposition
    • Ewa Klugmann-Radziemska
    • Małgorzata Rudnicka
    2020 Pełny tekst ENERGIES

    The aspect of dust accumulation on the surface of photovoltaic (PV) modules should be thoroughly understood in order to minimize possible obstacles affecting energy generation. Several elements affect the amount of pollutant gathered on the surface of a solar device, mainly its localization, which is irreversibly linked to factors such as annual rainfall, occasional snow coverage, or, in a dry climate, increased blow of dust during sandstorms and higher concentration of soil particles in desert areas. Other than weather conditions in the region, PV installation type also plays an important role as a more horizontal position is favorable for the accumulation of soil. The research carried out and presented in this paper was done for dust accumulated naturally on PV modules kept in outdoor conditions and dust artificially sieved onto the front glass cover of modules. The experiment performed by the authors, including artificially deposited dust, defined the linear relationship between surface dust density of different types of contaminants and efficiency decline up to 10% for two different PV modules. The additional field study carried out in external conditions for a coastal region in Northern Poland concluded that, after one year, exposition photovoltaic conversion efficiency can be over 10% lower, with a slight performance improvement for the autumn season characterized by heavy rainfall.

  • THE APPLICATION OF THE MECHANOCHEMICAL SYNTHESIS FOR THE PREPARATION OF ADVANCED CERAMICS BASED ON BARIUM TITANATE
    • Barbara Garbarz-Glos
    • Wojciech Bąk
    • Andrzej Budziak
    • Piotr Dulian
    • Agata Lisińska-Czekaj
    • Dionizy Czekaj
    2020 Pełny tekst ARCHIVES OF METALLURGY AND MATERIALS

    In the present study, the lead-free BaTi1-xZrxO3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to 10 MHz. The obtained measurement data, analyzed in accordance with the Arrhenius formalism demonstrated the presence of relaxation type dielectric mechanisms. The impedance answer of studied ceramic materials indicated the presence of two relaxation processes: one with a dominant resistive component and the other with a small capacitive component. The observed dielectric relaxation process is temperature dependent and has a “non-Debye” character.

  • The application of the Superpave method of climatic zones analysis in Poland with regard to bitumen performance grading
    • Marek Pszczoła
    • Dawid Ryś
    • Piotr Jaskuła
    2020

    Currently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard to mainly the penetration value determined at the tempera-ture of 25C. It should be noted that this classification is not correlated with the cli-matic conditions in which the bitumens are to serve in the road pavement. Towards the end of the last century a new system of bitumen grading was developed and im-plemented as part of the American Strategic Highway Research Program (SHRP). This paper presents the results of analyses concerning the determination of the tempera-tures at which bituminous binders serve in the Polish climatic conditions. A division of the area of Poland into climatic zones depending on the required performance grades (PGs) determined for bitumens on the basis of climatic data from meteorological sta-tions for a period of minimum 20 years is presented. It is proposed to select bitumens depending on the climatic zone in Poland, taking into account the proper probability level which follows from the road class.

  • The behavioural model of graphene field-effect transistor
    • Maciej Łuszczek
    • Marek Turzyński
    • Dariusz Świsulski
    2020 Pełny tekst International Journal of Electronics and Telecommunications

    The behavioural model of a graphene field-effect transistor (GFET) is proposed. In this approach the GFET element is treated as a “black box” with only external terminals available and without considering the physical phenomena directly. The presented circuit model was constructed to reflect steady-states characteristics taking also into account GFET capacitances. The authors’ model is defined by a relatively small number of equations which are not nested and all the parameters can be easily extracted. It was demonstrated that the proposed model allows to simulate the steady-state characteristics with the accuracy approximately as high as in the case of the physical model. The presented compact GFET model can be used for circuit or system-level simulations in the future.

  • The CDIO model in architectural education and research by design
    • Lucyna Nyka
    • Jan Cudzik
    • Katarzyna Urbanowicz
    2020 Pełny tekst World Transactions on Engineering and Technology Education

    Architectural education has always been related to experimentation: that is, defining concepts, drawing sketches, working on models, then testing and modifying them. This activity mirrors the CDIO learning methods and objectives. Despite this, research studies into the applicability of the CDIO model in architectural curricula are scarce. In the discipline of architecture, hands-on experiences are associated not only with one of the most effective methods of education, but also with a particular way of carrying out research, that is research by design. In this article, the authors present the integration of the CDIO framework into the architectural engineering curricula at Gdańsk University of Technology, Gdańsk, Poland, discuss the results, and indicate which components of architectural education have benefited most from this integration. Another objective was to initiate a discussion on the potential impacts of implementing CDIO into architectural curricula, and its relation to the research by design concept.

  • The correlation between the MRI-evaluated ectopic fat accumulation and the incidence of diabetes mellitus and hypertension depends on body mass index and waist circumference ratio.
    • Mariusz Kaszubowski
    • J Pieńkowska
    • B. Brzeska
    • O. Kozak
    • A. Jankowska
    • Edyta Szurowska
    2020 Pełny tekst PLOS ONE

    The widespread presence of overweight and obesity increases with every decade, and the number of people with body mass index (BMI) >30 kg/m2 has doubled in the last 30 years. The aim of the study is to assess the correlation between MRI-evaluated ectopic fat accumulation in pancreas, skeletal muscles and liver and the incidence of type 2 diabetes and hypertension, depending on BMI and waist circumference ratio. This prospective study included 267 consecutive patients who were referred to abdominal MRI and underwent a standard clinical assessment with BMI and waist circumference ratio calculation. Ectopic fat accumulation in pancreas, skeletal muscles and liver was evaluated in magnetic resonance imaging using the fat-water separated Dixon imaging. There were statistically significant differences in mean steatosis of all assessed organs in the group of patients with type 2 diabetes or hypertension in comparison to the non-diabetic group as well as to the group without hypertension. It has been observed that pancreas and skeletal muscles are more susceptible to fat accumulation than liver. According to our results, there is a relation between the fat content in muscles, pancreas and liver, the incidence of type 2 diabetes and hypertension and also body mass index and waist circumference ratio. We believe that future studies should aim to determine whether the use of fat content measurement in certain organs could be used as a biomarker that can enable early detection of reversible metabolic changes, as well as their subsequent monitoring.

  • The Design Development of the Sliding Table Saw Towards Improving Its Dynamic Properties
    • Kazimierz Orłowski
    • Przemysław Dudek
    • Daniel Chuchała
    • Wojciech Blacharski
    • Tomasz Przybyliński
    2020 Pełny tekst Applied Sciences-Basel

    Cutting wood with circular saws is a popular machining operation in the woodworking and furniture industries. In the latter sliding table saws (panel saws) are commonly used for cutting of medium density fiberboards (MDF), high density fiberboards (HDF), laminate veneer lumber (LVL), plywood and chipboards of different structures. The most demanded requirements for machine tools are accuracy and precision, which mainly depend on the static deformation and dynamic behavior of the machine tool under variable cutting forces. The aim of this study is to present a new holistic approach in the process of changing the sliding table saw design solutions in order to obtain a better machine tool that can compete in the contemporary machine tool market. This study presents design variants of saw spindles, the changes that increase the critical speeds of spindles, the measurement results of the dynamic properties of the main drive system, as well as the development of the machine body structure. It was proved that the use of only rational imitation in the spindle design on the basis of the other sliding table saws produced does not lead to the expected effect in the form of correct spindle operation.

  • The dispersive micro-solid phase extraction method for MS-based lipidomics of human breast milk*
    • Inal Bakhytkyzy
    • Weronika Hewelt-Belka
    • Agata Kot-Wasik
    2020 Pełny tekst MICROCHEMICAL JOURNAL

    A simple and rapid microextraction method ensuring high lipidome coverage was developed for liquid chromatography mass spectrometry (LC-MS)-based lipidomics of human breast milk. The dispersive microsolid phase extraction (D-µ-SPE) technique, coupled with the design of experiment (DoE) method, enabled the study of the influence of several conditions (desorption solvent, stationary phase ratio, and sorption and desorption time) on the lipid extraction process of various lipid classes. The D-µ-SPE-based method, which used a mixture of C18 and zirconia-coated silica gel as the sorbent, allowed for the extraction of a wide range lipid classes characterized by different concentration levels. The developed method simplified the extraction procedure for lipidomics without loss of good reproducibility (70% of the MFs had peak volume %RSD <20% for all the tested stationary phases). The highest lipidome coverage was achieved when 100 µL of the human breast milk (HBM) sample was extracted using 27 mg of C18 mixed with 3 mg of zirconia-coated silica gel as the sorbent and methanol:2-propanol: ammonium hydroxide (14:81:5 v/v/v) mixture as the desorption solvent. The sorption and desorption time did not influence the number of extracted molecular features. The advantages of the present method over the traditional SPE and liquid-liquid extraction (LLE) commonly used in lipidomics are the possibility of mixing sorbents with various sorption mechanisms, which ensures high lipidome coverage, and the use of a small number of materials, including the sorbent and organic solvent.

  • The dynamic signature verification using population-based vertical partitioning
    • Marcin Zalasiński
    • Krzysztof Cpałka
    • Tacjana Niksa-Rynkiewicz
    2020

    The dynamic signature is an attribute used in behavioral biometrics for verifying the identity of an individual. This attribute, apart from the shape of the signature, also contains information about the dynamics of the signing process described by the signals which tend to change over time. It is possible to process those signals in order to obtain descriptors of the signature characteristic of an individual user. One of the methods used in order to determine such descriptors is based on signals partitioning. In this paper, we propose a new method using a population-based algorithm for determining vertical partitions of the signature and its descriptors. Our method uses a Differential Evolution algorithm for signals partitioning and an authorial one-class fuzzy classifier for verifying the effectiveness of this process. In the simulations, we use a commercial BioSecure DS2 dynamic signature database.

  • The effect of Ag, Au, Pt, and Pd on the surface properties, photocatalytic activity and toxicity of multicomponent TiO2-based nanomaterials
    • Anna Malankowska
    • Alicja Mikołajczyk
    • Joanna Mędrzycka
    • Izabela Wysocka
    • Grzegorz Nowaczyk
    • Marcin Jarek
    • Tomasz Puzyn
    • Ewa Mulkiewicz
    2020 Environmental Science-Nano

    Multicomponent TiO2-based nanomaterials (MC-NMs) show better physicochemical properties than their individual components or bulk materials. However, the same unique properties that offer innovative applications might also pose unknown risks to human health and the environment. In this context, TiO2- based nanomaterials with a mixture of noble metal precursors (Ag, Au, Pt, and Pd) for large-scale technological applications in air purification were designed, synthesized and characterized. The influence of the type and amount of noble metal precursor on the optical properties and photocatalytic activity of MC-NMs and their toxicity to mouse embryo fibroblast cell line (BALB/3T3), human lung cell line (A549) and human liver cell line (HepG2) was investigated. A hazard assessment of the designed TiO2-based MCNMs was performed for the first time according to the standards developed under the Joint Research Center and NANoReg2 project (Horizon 2020). The threshold concentration of monometallic NPs that ensure high photocatalytic activity without increasing hazard to humans and the environment was determined. The results indicated that the most effective sample is represented by the 0.1Ag_0.1Au_0.1Pt_1Pd/TiO2 photocatalyst, in which noble metal NPs demonstrated a synergistic effect on photocatalytic activity without increasing the toxicity (safe MC-NMs with 86% toluene degradation after 1 h of irradiation, efficiency 5 times higher than that of pristine TiO2). The obtained results confirm that systematic knowledge and proper manipulation of component concentration may lead to rational design of safe TiO2-based MC-NMs with wide application in air purification under solar energy.

  • The Effect of AgInS2, SnS, CuS2, Bi2S3 Quantum Dots on the Surface Properties and Photocatalytic Activity of QDs-Sensitized TiO2 Composite
    • Anna Malankowska
    • Daria Kulesza
    • Jakub Sowik
    • Onur Cavdar
    • Tomasz Klimczuk
    • Grzegorz Trykowski
    • Adriana Zaleska-Medynska
    2020 Pełny tekst Catalysts

    The eect of type (AgInS2, SnS, CuS2, Bi2S3) and amount (5, 10, 15 wt%) of quantum dots (QDs) on the surface properties and photocatalytic activity of QDs-sensitized TiO2 composite, was investigated. AgInS2, SnS, CuS2, Bi2S3 QDs were obtained by hot-injection, sonochemical, microwave, and hot-injection method, respectively. To characterize of as-prepared samples high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray diraction (XRD), UV-Vis spectroscopy and photoluminescence (PL) emission spectroscopy were applied. The size of AgInS2, SnS, CuS2, Bi2S3 QDs were 12; 2–6; 2–3, and 1–2 nm, respectively. The QDs and QDs-sensitized TiO2 composites obtained have been tested in toluene degradation under LEDs light irradiation (max = 415 nm and max = 375 nm). For pristine QDs the eciency of toluene degradation increased in the order of AgInS2 < Bi2S3 < CuS < SnS under 375 nm and AgInS2 < CuS < Bi2S3 < SnS under 415 nm. In the presence of TiO2/SnS QDs_15% composite, 91% of toluene was degraded after 1 h of irradiation, and this eciency was about 12 higher than that for pristine QDs under 375 nm. Generally, building the TiO2/AgInS2 and TiO2/SnS exhibited higher photoactivity under 375 nm than the pristine TiO2 and QDs which suggests a synergistic eect between QDs and TiO2 matrix.

  • The effect of dehydration/rehydration of bacterial nanocellulose on its tensile strength and physicochemical properties
    • Alicja Stanisławska
    • Hanna Staroszczyk
    • Marek Szkodo
    2020 Pełny tekst CARBOHYDRATE POLYMERS

    Bacterial nanocellulose (BNC) is a natural biomaterial with a wide range of biomedical applications. BNC contains 99 % of water which makes it too thick to be used as a bioimplant material. The aim of the work was to determine the effect of the BNC dehydration followed by rehydration on its mechanical and physicochemical properties, in the context of the use of BNC as bio-prostheses in the cardiovascular system. Dehydration involved the convection-drying at 25 and 105 °C, and the freeze-drying, while rehydration - the soaking in water. All modified BNC samples had reduced thickness, and results obtained from FT-IR, XRD, and SEM analysis revealed that 25 °C BNC convection-dried after soaking in water was characterized by the highest: tensile strength (17.4 MPa), thermal stability (253 °C), dry mass content (4.34 %) and Iα/Iβ ratio (1.10). Therefore, 25 °C convection-dried BNC followed by soaking in water can be considered as a material suitable for cardio- vascular implants.

  • THE EFFECT OF DRYING INTENSITY ON THE COLOR CHANGES OF PINE WOOD (PINUS SYLVESTRIS L.)
    • Aleksandra Konopka
    • Jacek Barański
    • Kazimierz Orłowski
    • Daniel Chuchała
    2020 Pełny tekst Trieskove a Beztrieskove Obrabanie Dreva

    The effect of the selection of drying process parameters on the color change of Scots pine wood (Pinus Sylvestris L.) is presented. In this work the experimental studies have been performed. The research focused on the influence of drying intensity on the changes of color after drying process. Intensity of drying process was determined on the basis of the average drying gradient. To determine the color of wood before and after drying process the series of experiments have been performed, using color reader device. The wood samples were dried according to three different drying modes, namely: mild, normal and intense. Experiments were conducted in the laboratory dryer. The measurement of wood samples was made using international standards: ISO 11664-2 and ISO 11664-4 of total color change after drying. As a result of the performed statistical tests, there were observed statistically significant color changes of the wood surface for intensive drying mode.

  • The Effect of Fly Ash Microspheres on the Pore Structure of Concrete
    • Elżbieta Haustein
    • Aleksandra Kuryłowicz-Cudowska
    2020 Pełny tekst Minerals

    The fly ash microspheres (FAMs) formed during the mineral transformation stage in coal combustion are hollow spherical particles with a density less than water. This paper presents the results of X‐ray micro‐computed tomography and an automatic image analysis system of the porosity in the structure of hardened concrete with microspheres. Concrete mixtures with ordinary Portland cement and two substitution rates of cement by microspheres—5% and 10%—are investigated. For all considered mixes, a constant water/binder ratio (w/b) equal to 0.50 was used. The distribution of the air voids and the compressive strength of the concrete were tested after 28 days. With the increasing mass of cement replacement by FAMs, the compressive strength decreases after 28 days. The total volume of the air voids in hardened concrete with fly ash microspheres tested by X‐ray varies from 5.1% to 7.4%. The closed pores constitute more than 80% of the total content of air pores. The study proves that the use of microspheres grains with specific dimensions has a significant impact on concrete porosity. Their application in concrete technology can be an alternative aeration solution for fresh concrete mixes and an effective method for utilization.

  • The Effect of Laser Re-Solidification on Microstructure and Photo-Electrochemical Properties of Fe-Decorated TiO2 Nanotubes
    • Piotr Kupracz
    • Katarzyna Grochowska
    • Jakub Karczewski
    • Jakub Wawrzyniak
    • Katarzyna Siuzdak
    2020 Pełny tekst Materials

    Fossil fuels became increasingly unpleasant energy source due to their negative impact on the environment; thus, attractiveness of renewable, and especially solar energy, is growing worldwide. Among others, the research is focused on smart combination of simple compounds towards formation of the photoactive materials. Following that, our work concerns the optimized manipulation of laser light coupled with the iron sputtering to transform titania that is mostly UV-active, as well as exhibiting poor oxygen evolution reaction to the material responding to solar light, and that can be further used in water splitting process. The preparation route of the material was based on anodization providing well organized system of nanotubes, while magnetron sputtering ensures formation of thin iron films. The last step covering pulsed laser treatment of 355 nm wavelength significantly changes the material morphology and structure, inducing partial melting and formation of oxygen vacancies in the elementary cell. Depending on the applied fluence, anatase, rutile, and hematite phases were recognized in the final product. The formation of a re-solidified layer on the surface of the nanotubes, in which thickness depends on the laser fluence, was shown by microstructure studies. Although a drastic decrement of light absorption was recorded especially in UV range, laser-annealed samples have shown activity under visible light even 20 times higher than bare titania. Electrochemical analysis has shown that the improvement of photoresponse originates mainly from over an order of magnitude higher charge carrier density as revealed by Mott-Schottky analysis. The results show that intense laser light can modulate the semiconductor properties significantly and can be considered as a promising tool towards activation of initially inactive material for the visible light harvesting.

  • THE EFFECT OF LOG SORTING STRATEGY ON THE FORECASTED LUMBER VALUE AFTER SAWING PINE WOOD
    • Piotr Taube
    • Kazimierz Orłowski
    • Daniel Chuchała
    • Jakub Sandak
    2020 Pełny tekst ACTA FACULTATIS XYLOLOGIAE ZVOLEN

    The optimal transformation path for the resource is determined by the quality of a log combined with its dimension. The commercial value of derived products is also closely connected with the size and extent of containing wood deficiencies. The results of studies with three diverse strategies for log sorting are presented in the paper. Resource assessment by a worker without extensive experience in sorting logs, the certified grading expert, and the automatic in-line system including optical scanner with dedicated software are compared. It was shown that the lack of experience of the person performing the sorting operation results in reducing the potential economic profits of a sawmill. On the contrary, the overall efficiency of the log conversion process is considerably improved by the automated sorting systems with scanners. Early identification of logs optimal for specific lumber production is assured by reducing the human errors and subjective evaluation. Both, the yield of produced timber and profits of the sawmill are directly affected this way. It was demonstrated that the log sorting rate performed by the scanner is four times higher in comparison to grading by the certified expert, as well as three times higher compared to employee with no experience. The finding that the volume of high-quality lumber of elevated value is the lowest in the case the log is sorted by a human was proved.

  • The effect of morphology and crystalline structure of Mo/MoO3 layers on photocatalytic degradation of water organic pollutants
    • Mariusz Szkoda
    • Konrad Trzciński
    • Andrzej Nowak
    • Maria Gazda
    • Mirosław Sawczak
    • Anna Lisowska-Oleksiak
    2020 Pełny tekst MATERIALS CHEMISTRY AND PHYSICS

    Molybdenum oxide layers were formed by anodization of the Mo metallic foil in a water/ethylene glycol-based electrolyte containing fluoride ions. The as-prepared, amorphous samples were annealed in air at different temperatures in a range from 100 �C to 700 �C. The crystal phase and morphology of anodized and annealed MoO3 layers were investigated using X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The photoactivity of obtained materials was tested during a photocatalytic process of methylene blue (MB) decomposition. The increase of annealing temperature led to the production of films characterized by improved photocatalytic properties, with maximum photocatalytic efficiency observed for MoO3 annealed at 600 �C. The studies on the use of MoO3 as a photoelectrocatalyst for degradation of dye were performed. Furthermore, the photocatalytic activity of the MoO3 annealed at 600 �C was investigated during a photodegradation of diclofenac acting as a model pharmaceutical compound

  • The Effect of Posaconazole, Itraconazole and Voriconazole in the Culture Medium on Aspergillus fumigatus Triazole Resistance
    • Martyna Mroczyńska
    • Ewelina Kurzyk
    • Magdalena Śliwka-Kaszyńska
    • Urszula Nawrot,
    • Marta Adamik
    • Anna Brillowska-Dąbrowska
    2020 Pełny tekst Microorganisms

    Triazoles are the only compounds used as antibiotics in both medicine and agriculture. The presence of triazoles in the environment can contribute to the acquisition of azole resistance among isolates of Aspergillus fumigatus. The objective of this study was to investigate the effect of A. fumigatus exposure to triazoles on susceptibility to these compounds. Seventeen triazole-resistant and 21 triazole-sensitive A. fumigatus isolates were examined. The isolates were transferred 20 times on the Sabouraud medium supplemented with posaconazole, itraconazole or voriconazole, followed by five times on the medium not supplemented. The minimum inhibitory concentrations of antimycotics were examined according to the EUCAST broth microdilution method after the 20th transfer and also the 25th transfer. In addition, the expression levels of genes mdr1, mdr2, mdr3, atrF, cyp51A and cyp51B were determined. Cultivation of A. fumigatus on media supplemented with posaconazole, itraconazole and voriconazole resulted in the acquisition of resistance to the tested triazoles of all examined isolates. After recultivation on Sabouraud without azoles, most of the isolates lost their acquired resistance. The long-term use of triazole compounds in agriculture may result in the occurrence of triazole resistant A. fumigatus isolates in the environment, not only by induction or selection of mutations in the cyp51A gene, but also by contribution to changes in the gene expression.

  • The effectiveness of financial and economic regulation of land relations in the context of stimulating entrepreneurial activity in the regions of Ukraine
    • Uliana Vatamanyuk-Zelinska
    • Oleksandr Melnychenko
    2020 Pełny tekst Problems and Perspectives in Management

    Solving the problem of enhancing the efficiency of the financial and economic regulation of land relations contributes to the development of entrepreneurship in Ukraine. The purpose of the paper is to determine new incentives for encouraging entrepreneurial activity by increasing the efficiency of the financial and economic regulation of land relations by local governments. The study is based on applying the method for predicting amounts of local budget revenues in Ukraine from the land tax and lease fees through the use of communally owned land plots to stimulate entrepreneurial initiatives of the unemployed. In the process of research, the projected amounts of local budget revenues from financial transactions with plots of industrial lands in each region of Ukraine have been determined, taking into account the possibilities of leasing the lands, for which lease fees are covered by a one-time benefit provided to the unemployed for organizing entrepreneurial activity. It is proposed to determine the efficiency of the financial and economic regulation of land relations in the regions of Ukraine, applying indicators such as the use of industrial lands together with objects of lease located on them and the involvement of the unemployed from among the economically active population in entrepreneurial activity. To improve the efficiency of financial and economic regulation of land relations, local governments are proposed to establish the optimal proportion of amounts of borrowed resources, taking into account the need for their saving and rational use.

  • The effects of urban vehicle traffic on heavy metal contamination in road sweeping waste and bottom sediments of retention tanks
    • Nicole Nawrot
    • Ewa Wojciechowska
    • Shahabaldin Rezania
    • Jolanta Walkusz-miotk
    • Ksenia Pazdro
    2020 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    Diffuse pollution formed during a surface runoff on paved surfaces is a source of heavy metals (HMs) of various origin. This research study indicates the connection between bottom sediments of retention tanks located on urban streams and road sweeping wastes (RSW) that migrate during surface runoff to the stormwater drainage systems with discharge to the retention tanks. Moreover, we test the primary sources of HMs in RSW by analysing the mechanical wastes (MW) produced by vehicles in order to track the relationship between car parts and HMs deposited in the retention tanks receiving the surface runoff from streets. To identify the origin ofHMs diverse source tracking approaches were used: statisticalmethods, Pb isotope ratios, and the flag element ratio approach.MWpresented a very highHMs content (max observed values inmg/kg d.w.: 10477-Zn, 3512-Cu, 412-Pb, 3.35-Cd, 226-Ni, and 633-Cr), while for RSWthe HMs content was similar to the bottom sediments. The total carcinogenic risk raises concerns due to the Cr content. The source of Zn was tyre wear and traffic. Ni, Cr, Fe, and Cd were correlated to Zn and shared a common/similar origin. PCA suggested that Cu features quasiindependent behaviour. The Pb isotopic ratios of RSWindicated Pb enrichment originating fromcoal combustion, while the gasoline and diesel source of Pb was excluded. The Pb isotopic ratios characteristic for MW were in within the following ranges: 1.152–1.165 (206Pb/207Pb), 2.050–2.085 (208Pb/206Pb), and 2.350–2.418 (208Pb/207Pb). The complex analysis of HMs origin confirmed the motorization origin of HMs: Zn, Cr, Ni, and Cd, except Pb (coal combustion as the main source) and Cu (non-uniform origin). The results of various source tracking methods were coherent, but Pb isotope ratios alone brought important information allowing to link Pb in sediments to the atmospheric deposition of coal combustion products.

  • The electrochemical determination of isatin at nanocrystalline boron-doped diamond electrodes: stress monitoring of animals
    • Michał Sobaszek
    • Siuzdak Katarzyna
    • Jacek Ryl
    • Robert Bogdanowicz
    • Greg N. Swain
    2020 SENSORS AND ACTUATORS B-CHEMICAL

    Ultra-thin nanocrystalline boron-doped diamond electrodes (B:NCD) were used for the electrochemical determination of isatin in dog urine samples using cyclic voltammetry and square wave voltammetry in a phosphate buffer saline, pH = 7.2. No additional modification or pretreatment of the electrode surface was required in this approach, being of high importance for the facile detection procedure. The increase of the peak current was linearly related to the raised concentration of isatin in phosphate buffer. The limit of isatin detection was equal to 0.2 µM and 3 µM for B:NCD and reference glassy carbon electrodes respectively. The relatively high current sensitivities of 1.32 μAcm-2 μM-1 were achieved thanks to the nanocrystalline diamond surface. We have demonstrated that isatin could be determined at B:NCD electrode in the complex urine matrix within the limit of detection having 1 μM along with sensitivity of 0.46 μAcm-2 μM-1 without pre-treatment procedure of the analyte

  • The electronic excited states of dichloromethane in the 5.8-10.8 eV energy range investigated by experimental and theoretical methods
    • E. Lange
    • Nykola C. Jones
    • Søren Hoffmann
    • Ana Lozano
    • S. Kumar
    • M Homem
    • Małgorzata Śmiałek-Telega
    • Denis Duflot
    • M. Brunger
    • Paulo Limão-Vieira
    2020 Pełny tekst JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER

    We present a comprehensive experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of dichloromethane, CH 2 Cl 2 , with absolute cross sections determined for the full 5.8–10.8 eV energy-range. The calculations on the vertical excitation energies and oscillator strengths were performed using the equation-of-motion coupled cluster method, restricted to the single and double excitations level (EOM-CCSD), and were used to help analyse the valence and Rydberg structures in the photoab- sorption spectrum. The present spectrum additionally reveals several new features not previously re- ported in the literature, with particular reference to the valence σ∗C C l ( 10 a 1 ) ← n Cl ( 7 b 2 ) ( 1 1 B 2 ← ̃ X 1 A 1 ) and ( σ∗C C l ( 10 a 1 ) ← n Cl ( 9 a 1 ) + σ∗CH ( 11 a 1 ) ← n Cl ( 7 b 2 ) ) ( 1 1 A 1 ← ̃ X 1 A 1 ) transitions at 7.519 and 7.793 eV. A vibrational progression of the CCl 2 symmetric stretching, ν′ 3 , and CCl 2 scissoring, v ′ 4 ( a 1 ) , modes have also been assigned for the first time in the 7.4–8.6 eV energy range. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of dichloromethane in the Earth’s atmo- sphere (0–50 km). Potential energy curves as a function of the C–Cl coordinate, for the four lowest-lying excited A ′ and A ′′ electronic states, have additionally been calculated at the EOM-CCSD level of theory.

  • The experience of movement in orbital space architecture: A narrative of weightlessness
    • Mosleh Ahmadi
    • Nomusa Makhubu
    2020 Pełny tekst Cogent Arts & Humanities

    Based upon a combination of architectural theories, the knowledge of space environment, and psychology of isolated and confined environments, this qualitative research aims to study orbital space settlement in a way to get the built space congenial to the human experience of movement. In this sense, sensors, self-propulsion or mechanical actuators, the inhabitant’s mental and visual capacity for movement, as well as the represented and imbedded movement in the built environment—including pictorial representation, kinetic formation, and the movement of natural factors—are variables. So far, most of the studies on counter-measures for minimizing stress, which are stumbling blocks to the architectural promenade, have been based on pre-launch training focusing on professional training and selection of astronauts, planning for their in-flight challenges, and protecting them from dangers. Meanwhile, if we want to promote the experience of architecture in the outer space, narratives of movement need to be enriched, because not all occupants are professional astronauts. One way to study this matter is through analyzing movement in the built space and then synthesizing the results to gain an overview of a spatial montage in which motor planning for movement and route navigation have been facilitated. Narrative, in this sense, is a proper method to investigate this context of design. Therefore, analysis has been framed in the shape of a taxonomy of movement in weightlessness. Through a qualitative investigation in Cupola Module, it has been thrown into relief that movement with regard to space has not been enriched as much as movement with regard to the form.

  • The geometry of free-standing titania nanotubes as a critical factor controlling their optical and photoelectrochemical performance
    • Jakub Wawrzyniak
    • Katarzyna Grochowska
    • Jakub Karczewski
    • Piotr Kupracz
    • Jacek Ryl
    • Anna Dołęga
    • Siuzdak Katarzyna
    2020 SURFACE & COATINGS TECHNOLOGY

    Titanium dioxide nanotubes are regarded as one of the most important functional materials and due to their unique electronic properties, chemical stability and photocorrosion resistance, they find applications in, for example, highly efficient photocatalysis or perovskite solar cells. Nevertheless, modification of TiO2 nanotubes is required to overcome their main drawback, i.e. large energy bandgap (>3.2 eV) limiting their ability to capture solar light. In this work, we report the changes in optical and photoelectrochemical properties of well-separated TiO2 nanotubes that are tuned by varying the geometry of the material. The ordered tubular titania is formed via anodization in the presence of fluoride ions in diethylene glycol at elevated temperature. Length, inner diameter, wall thickness, and separation distance are described in function of synthesis parameters such as applied voltage and duration. The morphology and optical properties are characterized by means of scanning electron microscopy and UV–Vis spectroscopy techniques, respectively, while cyclic voltammetry, linear voltammetry and chronoamperometry are used to determine electrochemical/photoelectrochemical activity in different light conditions. The obtained results suggest a link between specific surface area, the width of the band-gap, and photoactivity, each of which could be individually optimised via anodization conditions. Moreover, the behaviour of the Mott-Schottky plot before and after 3 min of irradiation is studied indicating the positive shift of the flat band position and an increase in donor density values for all the obtained materials. The Mott-Schottky analysis was correlated with the linear voltammetry scans suggesting the important role of surface trapped holes. Presented in here results significantly supplement the current state-of-art regarding separated TiO2 nanotubes that are considered as not fully investigated and unappreciated class of titania materials which due to the exposure of inner and outer wall can be used for further modifications.

  • The hydration properties of protein stabilizer, trimethylamine-N-oxide in aqueous solutions of N-methylacetamide – The volumetric and compressibility studies between 288.15 and 308.15 K
    • Emilia Kaczkowska
    • Jarosław Wawer
    • Magdalena Tyczyńska
    • Małgorzata Jóźwiak
    • Agnieszka Boruń
    • Joanna Krakowiak
    2020 Pełny tekst THERMOCHIMICA ACTA

    Apparent molar volumes and apparent molar isentropic compressions of the protein stabilizer, trimethylamine-N-oxide (TMAO) were determined from the densities and speed of sound measured at T = (288.15, 298.15 and 308.15) K in aqueous solutions of N-methylacetamide (NMA) at four different concentrations (2, 4, 6 and 8 mol/kg). The concentration dependencies of the calculated quantities extrapolated to the infinite dilution lead to the standard partial molar properties. The latter values were combined with the previously published data for TMAO in pure water, to obtain the partial molar properties of transfer from water to aqueous NMA solutions. From the transfer data the interaction parameters were determined according to the McMillan-Mayer theory formalism. The calculated parameters and their temperature characteristics are discussed in terms of solute-solvent, solute-solute and solute-cosolute interactions and compared with analogous data for protein denaturant, n-butylurea.

  • The Immunogenic and Immunoprotective Activities of Recombinant Chimeric T. gondii Proteins Containing AMA1 Antigen Fragments
    • Justyna Gatkowska
    • Katarzyna Dzitko
    • Bartłomiej Ferra
    • Lucyna Holec-Gąsior
    • Malwina Kawka
    • Bożena Dziadek
    2020 Pełny tekst Vaccines

    Toxoplasmosis, one of the most common parasitoses worldwide, is potentially dangerous for individuals with a weakened immune system, but specific immunoprophylaxis intended for humans is still lacking. Thus, efforts have been made to create an efficient universal vaccine for both animals and humans to overcome the shortcomings of currently used treatment methods and protect all hosts against toxoplasmosis. The current work represents a relatively new approach to vaccine development based on recombinant chimeric Toxoplasma gondii antigens. In the present research, three tetravalent chimeric proteins containing different portions of the parasite’s AMA1 antigen: AMA1N-SAG2-GRA1-ROP1L (ANSGR), AMA1C-SAG2-GRA1-ROP1L (ACSGR) and AMA1-SAG2-GRA1-ROP1L (AFSGR) were tested for their immunogenic and immunoprotective capacities. All tested proteins were immunogenic, as evidenced by the triggering of specific humoral and cellular immune responses in vaccinated C3H/HeOuJ mice, defined by the production of specific IgG (IgG1/IgG2a) antibodies in vivo and synthesis of key Th1/Th2 cytokines by Toxoplasma lysate antigen-stimulated splenocytes in vitro. Although all tested preparations provided partial protection against chronic toxoplasmosis in immunized and T. gondii-challenged mice, the intensity of the generated immunoprotection depended on the fragment of the AMA1 antigen incorporated into the chimeric antigen’s structure.

  • The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
    • Ewa Janicka
    • Michał Mielniczek
    • Łukasz Gaweł
    • Kazimierz Darowicki
    • Paulina Landowska
    2020 ELECTROCHIMICA ACTA

    This paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance values. The influence of humidity on the charge transfer resistance behavior and the Warburg coefficient for varying current load values were analyzed in detail.

  • THE IMPACT OF GROUND TIRE RUBBER TREATMENT ON THE THERMAL CONDUCTIVITY OF FLEXIBLE POLYURETHANE/GROUND TIRE RUBBER COMPOSITES
    • Aleksander Hejna
    • Paulina Kosmela
    • Adam Olszewski
    • Łukasz Zedler
    • Krzysztof Formela
    2020 Pełny tekst

    Waste car tires are burdensome waste, and their utilization is crucial for the natural environment. In many countries, the primary method of their recycling is energy recovery, performed by simple combustion. However, material recycling is much more effective and significantly more beneficial for the natural environment. It results in the generation of ground tire rubber, which can be used to produce polymerrubber composites. It should be considered as a method of waste rubber utilization. Moreover, it may significantly reduce the use of petroleum-based polymers. Therefore, the environment's total impact could be noticeably reduced, which should be considered a convenient step towards more “green” polymer composites. In the presented paper, the impact of ground tire rubber treatment on the structure and insulation properties of flexible polyurethane/ground tire rubber composite foams was evaluated.