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Gdańsk University of Technology

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  • Therapeutic Potential of Carnosine and Its Derivatives in the Treatment of Human Diseases
    • Klaudia Chmielewska
    • Krystyna Dzierzbicka
    • Iwona Inkielewicz-Stępniak
    • Maja Przybyłowska
    2020 Full text CHEMICAL RESEARCH IN TOXICOLOGY

    Despite significant progress in the pathogenesis, diagnosis, treatment, and prevention of cancer and neurodegenerative diseases, their occurrence and mortality are still high around theworld. The resistance of cancer cells to the drugs remains a significant problem in oncology today,while in the case of neuro-degenerative diseases, therapies reversing the process are still yet to be found. Furthermore, it is important to seek new chemotherapeutics reversing side effects of currently used drugs or helping them perform their function to inhibit progression of the disease. Carnosine, a dipeptide constisting of β-alanine and L-histidine, has a variety of functions to mention: antioxidant, antiglycation, and reducing the toxicity of metal ions. It has therefore been proposed to act as a therapeutic agent for many pathological states. The aim of this paper was to find if carnosine and its derivatives can be helpful in treating various diseases. Literature search presented in this review includes review and original papers found in SciFinder, PubMed, and Google Scholar. Searches were based on substantial keywords concerning therapeutic usage of carnosine and its derivatives in several diseases including neurodegenerative disorders and cancer. In this paper, we review articles and find that carnosine and its derivatives are potential therapeutic agents in many diseases including cancer, neurodegenerative diseases, diabetes, and schizophrenia. Carnosine and its derivatives can be used in treating neurodegenerative diseases, cancer, diabetes, or schizophrenia, although their usage is limited. Therefore, there’s an urge to synthesize and analyze new substances,vercoming the limitation of carnosine itself.

  • Thermal Biomass Conversion: A Review
    • Witold Lewandowski
    • Michał Ryms
    • Wojciech Kosakowski
    2020 Full text Processes

    In this paper, the most important methods of thermal conversion of biomass, such as: hydrothermal carbonization (180–250 °C), torrefaction (200–300 °C), slow pyrolysis (carbonization) (300–450 °C), fast pyrolysis (500–800 °C), gasification (800–1000 °C), supercritical steam gasification, high temperature steam gasification (>1000 °C) and combustion, were gathered, compared and ranked according to increasing temperature. A comprehensive model of thermal conversion as a function of temperature, pressure and heating rate of biomass has been provided. For the most important, basic process, which is pyrolysis, five mechanisms of thermal decomposition kinetics of its components (lignin, cellulose, hemicellulose) were presented. The most important apparatuses and implementing devices have been provided for all biomass conversion methods excluding combustion. The process of combustion, which is energy recycling, was omitted in this review of biomass thermal conversion methods for two reasons. Firstly, the range of knowledge on combustion is too extensive and there is not enough space in this study to fully discuss it. Secondly, the authors believe that combustion is not an environmentally-friendly method of waste biomass utilization, and, in the case of valuable biomass, it is downright harmful. Chemical compounds contained in biomass, such as biochar, oils and gases, should be recovered and reused instead of being simply burnt—this way, non-renewable fuel consumption can be reduced.

  • Thermal failure of a second rotor stage in heavy duty gas turbine
    • Daniel Sławiński
    • Paweł Ziółkowski
    • Janusz Badur
    2020 Full text ENGINEERING FAILURE ANALYSIS

    The impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects of failure. Simulations were performed on undamaged blade geometry under load resulting from combustion: nominal fuel and the changed fuel. Thermodynamic calculations demonstrated a 70 °C increase in temperature using the changed fuel. The blade tip displacements demonstrated the possibility of abrasion. The amount of displacement of the tip of the turbine blade with increasing pressure or increasing rotational speed do not pose as great a threat, as does the increase in the temperature. To maintain long-term and safe operation of a gas turbine, it is necessary to strictly observe the manufacturer's guidelines regarding fuel composition. If during the operation of a gas turbine it is likely that it can be powered by various types of fuels, then the structure should have adequate effort reserves and working tolerances.

  • Thermal Images Analysis Methods using Deep Learning Techniques for the Needs of Remote Medical Diagnostics
    • Alicja Kwaśniewska
    2020 Full text

    Remote medical diagnostic solutions have recently gained more importance due to global demographic shifts and play a key role in evaluation of health status during epidemic. Contactless estimation of vital signs with image processing techniques is especially important since it allows for obtaining health status without the use of additional sensors. Thermography enables us to reveal additional details, imperceptible in images acquired with standard visible light cameras, yet, low resolution is its significant limitation. In the presented doctoral dissertation, original artificial intelligence solutions were proposed based on performed analysis of innovative thermal image processing methods using Deep Learning techniques for the needs of remote medical diagnostics. Possibility of modifying architecture of deep neural network designed for classification of visible light images in such a way that distribution of extracted features will be recreated enabling detection of facial areas from low resolution thermal data was verified in conducted experiments. Effectiveness of the proposed deep neural network architecture was demonstrated in practical applications, increasing resolution of thermal images and leading to better image quality metrics in comparison to stateof-the-art convolutional models, as well as increasing accuracy of facial areas detection, contactless estimation of respiratory rate and person recognition.

  • Thermally tuneable optical and electrochemical properties of Au-Cu nanomosaic formed over the host titanium dimples
    • Wiktoria Lipińska
    • Katarzyna Grochowska
    • Jakub Karczewski
    • Jacek Ryl
    • Adam Cenian
    • Siuzdak Katarzyna
    2020 Full text CHEMICAL ENGINEERING JOURNAL

    Au-Cu nanostructures offer unique optical and catalytic properties unlike the monometallic ones resulting from the specific interaction. Among others, they have the ability to exhibit surface plasmon resonance, electrochemical activity towards the oxygen and hydrogen evolution reaction (OER, HER) as well as improved photoresponse in relation to monometalic but those properties depend highly on the substrate where bimetallic structures are immobilized. In this work, bimetallic gold-copper mosaics over the conducting structured titanium substrate were fabricated via following steps: anodization of Ti foil, chemical etching of as-formed titania resulting in nanodimpled Ti substrate (TiND), sputtering of thin metal layer (Au, Cu) in various sequences, and finally thermal treatment in furnace at 450°C or 600°C. The morphology, optical and structural properties were investigated in details and it was shown that both arrangements of metallic films and thermal conditions strongly affect the morphology and optical features. The XPS results confirmed the presence of gold-copper alloys and copper oxide species. Last but not least, the electrochemical activities were verified in 0.1 M NaOH using cyclic voltammetry and linear voltammetry measurements performed in dark and under visible light illumination. Among all investigated materials in both anodic and cathodic regimes bimetallic 5Au/5Cu sample annealed at 450°C exhibits the highest response towards OER and HER, respectively. This is further boosted by the light with λ>420 nm. Upon exposure to visible light, the current density for 5Au/5Cu and 5Cu/5Au electrodes reached 1.32 mA cm-2 and 1.26 mA cm-2, respectively, while in the case of monometallic structures the current was below 10 μA cm-2. Both optical and electrochemical behaviour indicate a strong synergistic effect arising within the bimetallic mosaic formed over the TiND.

  • Thermal-Resistant Polyurethane/Nanoclay Powder Coatings: Degradation Kinetics Study
    • Maryam Jouyandeh
    • Behzad Hadavand
    • Farimah Tikhani
    • Reza Khalili
    • Babak Bagheri
    • Payam Zarrintaj
    • Krzysztof Formela
    • Henri Vahabi
    • Mohammad Saeb
    2020 Full text Coatings

    In the present study, thermal degradation kinetics of polyurethane (PU) powder coatings reinforced with organo-modified montmorillonite (OMMT) was investigated. PU nanocomposites were prepared in different concentrations of 1, 3, and 5 wt.% of OMMT via the extrusion method. The microstructure of the nanocomposites was observed by scanning electron microscope (SEM) illustrating uniform dispersion of OMMT nano-clay platelets in the PU matrix except for the sample containing 5 wt.% nano-palates. Thermal degradation kinetics of the PU nanocomposite was investigated using thermogravimetric analysis (TGA) at different heating rates of 5, 10, and 20 °C/min. The results showed that the initial decomposition temperatures were shifted toward higher values (more than 40 °C for T5% and up to 20 °C for T10%) by introducing the nano-clay to the PU matrix. Friedman, Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and modified Coats-Redfern iso-conversional methods were applied to model the decomposition reaction and the activation energy of the nanocomposite powder coatings. Overall, the presence of nano-clay increased the activation energy of the PU degradation up to 45 kJ/mol, when compared to the blank PU, which suggests very high thermal stability of nanocomposites. The Sestak-Berggren approach proposed a good approximation for the reaction model, especially at low temperatures. Thus, PU decomposition was detected as an autocatalytic reaction, which was suppressed by the barrier effect of OMMT nano-palates intercalated with polymer chains.

  • Thermochemical Conversion of Biomass and Municipal Waste into Useful Energy Using Advanced HiTAG/HiTSG Technology
    • Jan Stąsiek
    • Marek Szkodo
    2020 Full text ENERGIES

    An advanced thermal conversion system involving high-temperature gasification of biomass and municipal waste into biofuel, syngas or hydrogen-rich gas is presented in this paper. The decomposition of solid biomass and wastes by gasification is carried out experimentally with a modern and innovative regenerator and updraft continuous gasifier, among others. A ceramic high-cycle regenerator provides extra energy for the thermal conversion of biomass or any other solids waste. Highly preheated air and steam gas (heated up to 1600 C) was used as an oxidizing or gasification agent (feed gas). Preheated feed gas also enhances the thermal decomposition of the gasification solids for fuel gas. However, the main objective of this work is to promote new and advanced technology for the thermochemical conversion of biomass for alternative energy production. Selected results from experimental and numerical studies are also presented.

  • Thermodynamic study of binary mixtures of toluene with ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide
    • Dorota Warmińska
    • Iwona Cichowska-Kopczyńska
    2020 Full text JOURNAL OF MOLECULAR LIQUIDS

    Densities, refractive indices and viscosities at 293.15, 298.15, 303.15, 308.15 and 313.15 K of binary mixtures of toluene with 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide and 1-butylpyridinium bis(trifluoromethylsulfonyl)imide have been measured over the miscible region at p = 0.1 MPa. From the experimental data, values of excess molar volume, excess thermal expansion, deviation in refractive index, deviation in viscosity and excess Gibbs energy of activation for viscous flow have been calculated. These properties have been fitted to the Redlich-Kister-type polynomial equation in order to analyse non-ideal behaviour of the studied mixtures. Moreover, partial and apparent molar volumes of toluene and ionic liquid in their binary systems have been calculated. Finally, the effects of temperature and cation of ionic liquid on the physicochemical properties were analysed and discussed in terms of intermolecular interactions occurring in the studied systems.

  • Thermohydraulic maldistribution reduction in mini heat exchangers
    • Paweł Dąbrowski
    2020 Full text APPLIED THERMAL ENGINEERING

    A detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel 1 mm × 1 mm rectangular minichannels and 1 mm depth minigap section with rectangular, trapezoidal, triangular or concave manifolds in Z-type flow configuration. The working medium was ethanol and the mass flow rate was 5 × 10−4 kg/s. Both sections were heated from the bottom side. Heat flux of 10 000 W/m2 and 5000 W/m2 was applied to the minichannel and minigap section respectively. The method of the flow maldistribution mitigation in the diabatic flow has been checked. Thanks to introducing a threshold, the maldistribution coefficient can be reduced about twice in the minigap section or three times in the minichannel section with the 0.5 mm threshold as compared to the conventional arrangement. The velocity profile and temperature profile over the heat exchanger’s surface have been analyzed. Reduction of the maldistribution results in lower maximum temperature over the surface. The distribution is more uniform in the minichannel section than in the minigap section. This is due to a two-dimensional flow over a minigap. Hence, a two-dimensional approach to define maldistribution coefficients in minigap sections, which has not been distinguished in literature yet was used.

  • Thermophysical study of the binary mixtures of triethyl phosphate with N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide – Experimental and theoretical approach
    • Dorota Warmińska
    • Maciej Śmiechowski
    2020 Full text JOURNAL OF MOLECULAR LIQUIDS

    Densities at (293.15, 298.15, 303.15 and 308.15) K, and viscosities and ultrasonic velocities at 298.15 K of binary liquid mixtures of triethyl phosphate with N-methylformamide, N,N-dimethylformamide and N,N-dimethylacetamide have been measured over the entire range of composition at p = 0.1 MPa. From the experimental data, values of excess molar volume, excess isentropic compressibility, viscosity deviation and excess Gibbs energy of activation for viscous flow have been calculated. These results were fitted to the Redlich-Kister-type polynomial equation. The viscosity deviations and the excess Gibbs energy were found to be positive for the all systems investigated, while the excess volumes and the excess isentropic compressibilities were negative for TEP + DMA and for TEP + DMF systems, and positive for mixtures TEP + NMF. These results were interpreted based on the strength of the specific interaction, size and shape of molecules. Molecular dynamics simulations were used to provide a detailed explanation of the differences between the TEP + NMF and other systems, which were ultimately traced to strong hydrogen bonding between NMF and TEP.

  • Thickness accuracy of sash gang sawing
    • Kazimierz Orłowski
    • Jakub Sandak
    • Daniel Chuchała
    2020 Full text BIORESOURCES

    Thin lamellae, corresponding to the layer components of structural glued members, i.e. 2-ply or 3-ply glued parquet, can be manufactured in re-sawing operations of kiln-dried wood blocks. These must be prepared with high dimensional accuracy and adequate surface quality following specific technical requirements for lamellae thickness variations, especially in the upper layers of the glued composite parquet. The accuracy of oak lamellae thickness was examined here for a re-sawing process performed on the sash gang saw. A series of cutting tests were carried out in sawmill production conditions. The overall objective for these observations was to determine an effect of both the cumulative time of sawing (progress of the tool wear) and the lamella position (distribution of lateral forces) on the dimensional accuracy of production. Lamellae size control was conducted following the Brown methodology. Detailed within-board, between-board, and total sawing standard deviations for the examined lamellae positions in the gang were determined. The obtained results revealed that outermost lamellae are more subjected to dimensional inaccuracy than lamellae from the centre of the sawn block or frieze

  • Three-dimensional printed trachea helps to design tailored treatment for tracheobronchomalacia
    • Robert Dziedzic
    • Gustaw Rzyman
    • Witold Rzyman
    2020 Full text Polish Archives of Internal Medicine

    Tracheobronchomalacia is a rare respiratory disease that is manifesting by impaired ventilation with expiratory collapse of the tracheal wall due to softening of the supporting cartilage and hypotonia of myoelastic elements [1]. Surgery is the mainstay of treatment. We report the case of 39 -year old man with exacerbation of chronic respiratory distress. The membranous wall of the trachea and the large bronchi was stretched to such an extent that the tracheal lumen was almost completely closed during the exhalation phase, and the cartilage bent in the opposite direction taking the opposite C-shape. To plan the operation in detail, we used 3D printing. We made the airway model in 3d using the GE AW-suite software. Then the model was printed on a 3d printer in plastic. The tracheobronchoplasty through right posterolateral thoracotomy was performed. A polipropylen mesh was sewn into the membranous wall of the trachea and main bronchi. A satisfactory wallresult was obtained. 3D printed trachea was very helpful in the planning of the operational strategy.

  • Tight bounds on global edge and complete alliances in trees
    • Kacper Wereszko
    • Robert Kozakiewicz
    • Robert Lewoń
    • Michał Małafiejski
    2020

    In the talk the authors present some tight upper bounds on global edge alliance number and global complete alliance number of trees. Moreover, we present our NP-completeness results from [8] for global edge alliances and global complete alliances on subcubic bipartite graphs without pendant vertices. We discuss also polynomial time exact algorithms for finding the minimum global edge alliance on trees [7] and complete alliance on trees [8].

  • TIM
    • Luciano Segreto
    2020

    .

  • Time Domain Modeling of Propeller Forces due to Ventilation in Static and Dynamic Conditions
    • Anna Kozłowska
    2020 Full text Journal of Marine Science and Engineering

    This paper presents experimental and theoretical studies on the dynamic effect on the propeller loading due to ventilation by using a simulation model that generates a time domain solution for propeller forces in varying operational conditions. For ventilation modeling, the simulation model applies a formula based on the idea that the change in lift coefficient due to ventilation computes the change in the thrust coefficient. It is discussed how dynamic effects, like hysteresis effects and blade frequency dynamics, can be included in the simulation model. Simulation model validation was completed by comparison with CFD (computational fluid dynamics) calculations and model experiments. Experiments were performed for static and dynamic (heave motion) conditions in the large towing tank at the SINTEF Ocean in Trondheim and in the Marine Cybernetics Laboratories at NTNU (Norwegian University of Science and Technology). The main focus of this paper is to explain and validate the prediction model for thrust loss due to ventilation and out of water effects in static and dynamic heave conditions.

  • TiO2-based magnetic nanocomposites with core-shell structure
    • Zuzanna Bielan
    2020 Full text

    The main aim of the doctoral dissertation was preparation and characterization of photocatalysts, with particular emphasis on modified titanium (IV) oxide photocatalysts, which can be applied for the degradation of organic pollutants not susceptible to biodegradation. A particularly important aspect of the work was the development of preparation method of nanocomposites with the magnetic core-shell and photocatalyst shell (TiO2) structure, photocatalytic active under UV/Vis radiation. The use of the microemulsion method for the preparation of magnetic nanocomposites allowed for the creation of the desired structure, in which the core of the nanocomposite was iron (II) diiron (III), (Fe3O4), covered with a layer of inert silica and TiO2 photocatalyst. The second scientific aspect of the work was to increase the photocatalytic activity of the obtained nanocomposites in UV/Vis light and visible light by modifying the titanium(IV) oxide surface with platinum and copper, as well as introducing titanium defects into the crystal structure of TiO2. The obtained nanocomposites were used for the effective degradation of persistent organic pollutants present in flowback water after the hydraulic fracturing process and carbamazepine, a commonly used antiepileptic drug, classified as a pharmaceutical pollutant of the aquatic environment.

  • To Survive in a CBRN Hostile Environment: Application of CAVE Automatic Virtual Environments in First Responder Training
    • Paweł Maciejewski
    • Małgorzata Gawlik-Kobylińska
    • Jacek Lebiedź
    • Witold Ostant
    • Doğan Aydın
    2020

    This paper is of a conceptual nature and focuses on the use of a specific virtual reality environment in civil-military training. We analyzed the didactic potential of so-called CAVE automatic virtual environments for First Responder training, a type of training that fills the gap between First Aid training and the training received by emergency medical technicians. Since real training involves live drills based on unexpected situations, it is expensive and difficult to organize. We propose the application of virtual environments of three different sizes to increase the effectiveness of First Responder training. Our findings show that using the CAVEs allows for easier adaptation of the learning environment to a specific scenario while reducing costs from preparing training fields. The environments are also safer for trainees who must perform tasks related to hazardous materials. The analysis was based on the facilities at the Immersive 3D Visualization Lab (I3DVL) at Gdańsk University of Technology in Poland. We believe that, in the context of emerging threats of chemical, biological, radiological, and nuclear terrorism, such training is a necessity. The application of artificial intelligence can be considered as a further step in the facility development to increase the training fidelity.

  • Toksyny grzybów kapeluszowych. Rozdz. 10
    • Roman Kotłowski
    2020

    W rozdziale nr 10 brak abstraktu

  • Tool Wear Prediction in Single-Sided Lapping Process
    • Norbert Piotrowski
    2020 Full text Machines

    Single-sided lapping is one of the most effective planarization technologies. The process has relatively complex kinematics and it is determined by a number of inputs parameters. It has been noted that prediction of the tool wear during the process is critical for product quality control. To determine the profile wear of the lapping plate, a computer model which simulates abrasive grains trajectories was developed in MATLAB. Moreover, a data-driven technique was investigated to indicate the relationship between the tool wear uniformity and lapping parameters such as the position of conditioning rings and rotational speed of the lapping plate and conditioning rings.

  • Toolchain Modeling: Comprehensive Engineering Plans for Industry 4.0
    • Geza Kulcsar
    • Marek Tatara
    • Federico Montori
    2020 Full text

    The fourth industrial revolution (Industry 4.0) elevates the complexity and autonomy of industrial systems and engineering environments to levels not seen before. The novel challenges involve not only the software running on the partaking autonomous devices, but also architectural considerations and the technological infrastructure around the entire engineering process. In this paper, complementing the trends in industrial systems design, we propose an approach to toolchain modeling, i.e. an integrated specification for the interoperability of tools along with the holistic architectural framework, designed in the context of the Arrowhead Framework. In particular, we propose an intuitive, yet founded definition for toolchains and their mappings to a versatile engineering process model. Those definitions then serve as a basis for proposing our comprehensive toolchain modeling approach. The methodology is demonstrated using (simplified) real-world engineering case studies based on the Arrowhead Framework and platform.

  • Topological degree for equivariant gradient perturbations of an unbounded self-adjoint operator in Hilbert space
    • Piotr Bartłomiejczyk
    • Bartosz Kamedulski
    • Piotr Nowak-Przygodzki
    2020 Full text TOPOLOGY AND ITS APPLICATIONS

    We present a version of the equivariant gradient degree defined for equivariant gradient perturbations of an equivariant unbounded self-adjoint operator with purely discrete spectrum in Hilbert space. Two possible applications are discussed.

  • Torsional stability capacity of a nano-composite shell based on a nonlocal strain gradient shell model under a three-dimensional magnetic field
    • Mohammad Malikan
    • Maxim Krasheninnikov
    • Victor Eremeev
    2020 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    This paper considers a single-walled composite nano-shell (SWCNS) exposed in a torsional critical stability situation. As the magnetic field affects remarkably nanostructures in the small size, a three-dimensional magnetic field is assessed which contains magnetic effects along the circumferential, radial and axial coordinates system. Based on the results of the nonlocal model of strain gradient small-scale approach and the first-order shear deformation shell theory (FSDST), the problem is estimated. Afterward, the numerical results are taken analytically and compared with other existing literature. Hereafter, the influences of various factors, such as the magnetic field, are discussed deeply. It is observed that when the magnetic field is studied in three dimensions, the transverse magnetic effect is the most serious factor that affects fundamentally the torsional stability of the shell.

  • Total cross section measurements for electron scattering from tin(IV) chloride (SnCl4)
    • Paweł Możejko
    • Sylwia Stefanowska-Tur
    • Elżbieta Ptasińska-Denga
    • Czesław Szmytkowski
    2020 Full text Journal of Physics : Conference Series

    Total cross section for electron scattering from SnCl4 molecules has been measured for energies from 0.6 to 300 eV. Obtained results have been compared with total cross sections for electron scattering from other tetrachloride molecules: XCl4 where X=C, Si, Ge.

  • Toward Robust Pedestrian Detection With Data Augmentation
    • Sebastian Cygert
    • Andrzej Czyżewski
    2020 Full text IEEE Access

    In this article, the problem of creating a safe pedestrian detection model that can operate in the real world is tackled. While recent advances have led to significantly improved detection accuracy on various benchmarks, existing deep learning models are vulnerable to invisible to the human eye changes in the input image which raises concerns about its safety. A popular and simple technique for improving robustness is using data augmentation. In this work, the robustness of existing data augmentation techniques is evaluated to propose a new simple augmentation scheme where during training, an image is combined with a patch of a stylized version of that image. Evaluation of pedestrian detection models robustness and uncertainty calibration under naturally occurring corruption and in realistic cross-dataset evaluation setting is conducted to show that our proposed solution improves upon previous work. In this paper, the importance of testing the robustness of recognition models is emphasized and it shows a simple way to improve it, which is a step towards creating robust pedestrian and object detection models.

  • Towards a Lightweight Approach for the Evaluation of Requirements Engineering Impact on Other IT Project Areas
    • Aleksander Jarzębowicz
    • Katarzyna Poniatowska
    2020 Full text

    Requirements Engineering (RE) is recognized as one of the most important, but difficult areas of software engineering, with a significant impact on other areas of the IT project and its final outcome. The empirical studies investigating this impact are hard to conduct, mainly due to large effort required. It is thus difficult for researchers and even more for industry practitioners to make evidence-based evaluations, how decisions about RE (e.g. RE process improvements, RE techniques selection) translate into requirements quality and influence other project areas. We propose an idea of a lightweight approach, utilizing the popular tools adopted by numerous software companies, to enable such evaluation without an excessive effort. The proposal is illustrated with a pilot study, where the data from 6 industrial projects from a single organization was analyzed and 3 metrics regarding requirements quality, rework effort and testing were used to demonstrate the impact of different RE techniques applied among considered projects. We also discuss the factors important to enabling adoption of the proposed approach.

  • Towards Changes of Macro-Economic Structures in Middle Eastern Countries. Empirical Evidence for 1970–2018
    • Ewa Lechman
    • Radosław Ślosarski
    2020

    Middle East countries share a wide bundle of specific structural economic features and one of the latest is a high dependency of these economies on fossil fuels, which is quantitatively demonstrated through the share of oil and gas revenues in total export, but also in gross domestic product composition. This high economic dependency on natural resources on one hand has recently generated a material wealth of Middle Eastern countries which is demonstrated in a gross domestic product, but—on the other hand, contemporary global challenges such as price shocks on international commodity markets are calling for urgent diversification of national economies. This research aims to review key structural features of the economies of the six-member states of the Gulf Cooperation Council and changes in their macroeconomic structures between 1970-2018. It shows country-wise evidence, with respect to diversification of gross domestic product composition, identifying structural shifts between industry, service and agricultural sector. To provide more specific insight into the structure of national economies it examines time changes in oil rents (as a share of GDP), natural gas rents (as a share of GDP), fuel exports (share of merchandise exports). Finally, to verify the hypothesis that shifts in economic structure and GDP composition are accompanied by changes in sources of electricity production. Hence we additionally rely on data regarding sources of electricity production like coal, natural gas, oil, hydroelectric power plants (hydropower) and renewable sources (excluding hydroelectric but including geothermal, solar, tides, wind, biomass, and biofuels). Our methodological settings combine elementary descriptive statistics, time trends analysis, locally weighted polynomial smoothers for visual inspection of pair-wise correlations and panel regression models to capture statistical relationships between data examined. All macroeconomic data used in this research are exclusively extracted from World Development Indicators 2019.

  • Towards Extending Wikipedia with Bidirectional Links
    • Szymon Olewniczak
    • Tomasz Boiński
    • Julian Szymański
    2020 Full text

    In this paper, we present the results of our WikiLinks project which aims at extending current Wikipedia linkage mechanisms. Wikipedia has become recently one of the most important information sources on the Internet, which still is based on relatively simple linkage facilities. A WikiLinks system extends the Wikipedia with bidirectional links between fragments of articles. However, there were several attempts to introduce bidirectional fragment-fragment links to the Web, WikiLinks project is the first attempt to bring the new linkage mechanism directly to Wikipedia.

  • Towards Greater Citizen Participation in Financing Public Cultural Institutions—Legal Barriers and Proposed Solutions
    • Anna Modzelewska
    • Sebastian Skuza
    • Marta Szeluga-Romańska
    • Marta Materska-Samek
    2020 Full text Sustainability

    The paper contains a conceptual proposal that aims at indicating new models of participatory financing of cultural institutions as well as actions towards supporting culture. It presents results of a qualitative study in the form of action research, on identifying legal barriers of financing of cultural institutions in Poland. Additionally, it presents practical suggestions to the encountered problems that were worked out after discussions with cultural managers, taxpayers, and government administration decision-makers. The unique value of the study is a multidimensional and complex analysis of participatory financing of culture, citing varied sources and bearing a structured research procedure. We suggest a new discussion on establishing legal solutions for increasing of the funding or making the financing of cultural institutions more flexible, which appears to be particularly important in crisis times. All is presented as an original concept of participatory citizen-enterprise fiscal mechanism of supporting cultural institutions. We present a pragmatic solution to a problem of additional public support of culture, which can be put into practice parallel to state mechanisms, considering culture as a part of sustainable development.

  • Towards Improving Optimised Ship Weather Routing
    • Roberto Vettor
    • Joanna Szłapczyńska
    • Rafał Szłapczyński
    • Wojciech Tycholiz
    • Carlos Guedes Soares
    2020 Full text Polish Maritime Research

    The aim of the paper is to outline a project focusing on the development of a new type of ship weather routing solution with improved uncertainty handling, through better estimation of ship performance and responses to sea conditions. Ensemble forecasting is considered to take into account the uncertainty levels that are typical of operations in a stochastic environment. Increased accuracy of weather prediction is achieved through the assimilation of real-time data, measured by an on-board monitoring system. The proposed system will allow smooth integration of short-term Decision Support Systems for ship handling in dangerous or peculiar situations with long-term Decision Support Systems for weather routing. An appropriate user interface is also a critical part of the project and it will be implemented in a commercial Electronic Nautical Chart environment. A prototype of the full system will be installed and tested on a commercial vessel in regular operations and under real environmental conditions.

  • Towards Synthetic and Balanced Digital Government Benchmarking
    • Jaromir Durkiewicz
    • Tomasz Janowski
    2020 Full text

    Reliable benchmarking is essential for effective management of the government digitalization efforts. Existing benchmarking instruments generally fail to support this target. One problem is the diversity of instruments, resulting in a split image of digital progress and adding ambiguity to policy decisions. Another problem is disconnect in assessing progress between digital and traditional “analog” governance, lending support to a dangerous idea that countries can compensate for lack of progress in their governance systems by simply digitalizing them. This paper provides a path to addressing both problems by: aggregating relevant indicators of the World Economic Forum’s Network Readiness Index (NRI) to obtain a single synthetic measure of digital government, balancing this measure with progress in analog governance using World Bank’s Worldwide Governance Indicators (WGI), calculating new measures for the latest editions of NRI and WGI, and discussing results. Technically, the paper applies multidimensional linear ordering and factor analysis.

  • Toxoplasma gondii Recombinant antigen AMA1: Diagnostic Utility of Protein Fragments for the Detection of IgG and IgM Antibodies
    • Bartłomiej Ferra
    • Lucyna Holec-Gąsior
    • Justyna Gatkowska
    • Bożena Dziadek
    • Katarzyna Dzitko
    2020 Full text Pathogens

    Toxoplasma gondii is an important zoonotic protozoan that infects a wide variety of vertebrates as intermediate hosts. For this reason, the diagnosis of this disease is very important and requires continuous improvement. One possibility is to use recombinant antigens in serological tests. Apical membrane antigen 1 (AMA1), a protein located in specific secretory organelles (micronemes) of T. gondii, is very interesting in regard to its potential diagnostic utility. In the present study, we attempted to identify a fragment of the AMA1 protein with a high sensitivity and specificity for the serological diagnosis of human toxoplasmosis. The full-length AMA1 and two different fragments (AMA1N and AMA1C) were produced using an Escherichia coli expression system. After purification by metal affinity chromatography, recombinant proteins were tested for their utility as antigens in enzyme-linked immunosorbent assays (ELISAs) for the detection of IgG and IgM anti-T. gondii antibodies in human and mouse immune sera. Our data demonstrate that the full-length AMA1 recombinant antigen (corresponding to amino acid residues 67–569 of the native protein) has a better diagnostic potential than its N- or C-terminal fragments. This recombinant protein strongly interacts with specific anti-T. gondii IgG (99.4%) and IgM (80.0%) antibodies, and may be used for developing new tools for diagnostics of toxoplasmosis.

  • Toxoplasma gondii Recombinant Antigens in the Serodiagnosis of Toxoplasmosis in Domestic and Farm Animals
    • Bartłomiej Ferra
    • Lucyna Holec-Gąsior
    • Weronika Grąźlewska
    2020 Full text Animals

    Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, and is a parasitic disease that occurs in all warm-blooded animals, including humans. Toxoplasmosis is one of the most common parasitic diseases of animals and results in reproductive losses. Toxoplasmosis in humans is usually caused by eating raw or undercooked meat or consuming dairy products containing the parasite. Diagnosis of toxoplasmosis is currently based on serological assays using native antigens to detect specific anti-T. gondii antibodies. Due to the high price, the available commercial agglutination assays are not suited to test a large number of animal serum samples. The recent development of proteomics elucidated the antigenic structure of T. gondii and enabled the development of various recombinant antigens that can be used in new, cheaper, and more effective diagnostic tools. Continuous development of scientific disciplines, such as molecular biology and genetic engineering, allows for the production of new recombinant antigens and provides the basis for new diagnostic tests for the detection of anti-T. gondii antibodies in animal serum samples.

  • Trace elements content of surface peat deposits in the Solovetsky Islands (White Sea)
    • Krystyna Kozioł
    • Joanna Korzeniowska
    • Daniel Okupny
    • Elżbieta Bezak-mazur
    • Stanisław Żurek
    2020 Full text Mires and Peat

    Peatlands form environmental archives of trace element deposition. In this regard they are particularly valuable for areas such as the Arctic, where regular pollution monitoring is either impossible or extremely costly. The aim of this study was to assess pollution in the Solovetsky Islands (65° 05' N, 35° 53' E) by examining the spatial variability in trace element content of the uppermost layer of peat, immediately below the surface layer of green vegetation. We evaluated Cr, Cd, Ni and Pb contents in samples taken from ombrotrophic (raised bog) and mesotrophic (transitional) mires and in different microtopographical settings (hummock/hollow), and calculated the following pollution indices: geoaccumulation index (Igeo), contamination factor (Cf) and degree of contamination (Cdeg). The contents of these elements were markedly lower in the Solovetsky Islands than reported from other parts of central and northern Europe. Depending on the pollution index considered, the studied peat samples could be classified as unpolluted to considerably polluted. The local spatial patterns showed the highest values of Cd in samples collected near the sea, while the highest contents of Cr and Ni were noted at sampling points located farther inland. Moreover, Cr and Pb concentrations were higher in raised bogs than in transitional mires, and this contrast was accentuated if raised bog was represented by hummocks alone. These patterns are consistent with the likely sources of Cr, Ni and Pb being atmospheric pollution; and with higher mobility of Cd in seawater, which periodically floods the transitional mires. Amongst the trace elements determined, the most consistent values across peat types and sampling locations were found for Ni, which could be successfully used for pollution monitoring even in transitional mires.

  • Transformacja Dworca Morskiego w Gdyni na Muzeum Emigracji
    • Robert Hirsch
    2020 Full text Ochrona Dziedzictwa Kulturowego

    Artykuł omawia współczesne adaptacje budynków historycznych w Polsce, określając dwa główne nurty: komercyjny i niekomercyjny. Jako przykład niekomercyjnej transformacji przedstawiony został przypadek modernistycznego Dworca Morskiego w Gdyni z lat 30. XX w. przekształconego na Muzeum Emigracji. Przedsięwzięcie zakończone uroczystym otwarciem muzeum w 2015 r. zyskało wiele przychylnych opinii i zostało laureatem w konkursie "Zabytek zadbany", organizowanym przez Generalnego Konserwatora Zabytków. Pomimo pozytywnych efektów tej transformacji, w artykule podjęto próbę krytycznej oceny tej inwestycji pod względem konserwatorskim.

  • Transient modeling in common DC link of power converters
    • A. Anuchin
    • G.l. Demidova
    • Ryszard Strzelecki
    • M.s. Yakovenko
    2020 Full text Science, Technology and Arts Research Journal

    Предмет исследования. Представлена математическая модель силовых преобразователей электропривода, питающихся от общего звена постоянного тока, на примере тяговых электроприводов карьерного самосвала БЕЛАЗ-90 мощностью 280 кВт. Модель выполнена в пакете MATLAB/Simulink. Новизна предложенной модели заключается в применении новой топологии силовой схемы для исследования работы двух инверторов, под- ключенных к одному звену постоянного тока. Представлена возможность исследования переходных процессов в распределенном звене постоянного тока с целью уменьшения пульсаций тока, как в конденсаторной батарее инверторов, так и в общем звене постоянного тока. Метод. В целях снижения пульсаций на аппаратном уровне предложен метод введения дополнительной индуктивности между конденсаторами инверторов. С этой же целью при широтно-импульсной модуляции на алгоритмическом уровне предложено введение фазового сдвига опор- ных сигналов двух параллельно работающих инверторов. Разработана математическая модель, позволяющая оценивать пульсации тока между инвертором и конденсатором звена постоянного тока и между конденсатором и источником питания. Основные результаты. Показано, что алгоритмический метод вдвое снижает пульсации тока между инвертором и конденсатором звена постоянного тока и до 10 раз снижает ток между конденсатором инвертора и источником питания. Практическая значимость. Предложенная модель может быть использована при проверке токовой нагрузки элементов силового преобразователя в процессе проектирования систем мно- годвигательного электропривода (станочные приводы, гибридные транспортные средства).

  • Transient States during Short-circuit in a Line Powered by UPS and its Impact on Earth Fault Loop Impedance Measurement and Power Quality
    • Jacek Katarzyński
    • Marek Olesz
    2020

    The short-circuit in a line powered by Uninterruptible Power Supply (UPS) during different UPS operation modes is presented in the article. The transient state condition related to the short-circuit in a line fed from double conversion On-line UPS is discussed in detail. The results of the measurements of earth fault loop impedance (FLI) in circuits powered by UPS with the instruments of various manufacturers are presented. The dispersion of the measurement results, depending on UPS operation mode and on the instrument test current value is observed. The uncertainty of FLI measurement in UPS-powered circuits is pointed out, and its impact on the power quality and the evaluation of effectiveness of protection against electric shock is explained.

  • Transport of paracetamol in swellable and relaxing polyurethane nanocomposite hydrogels
    • Marta Motke
    • Justyna Strankowska
    • Jerzy Kwela
    • Marek Józefowicz
    • Michał Strankowski
    2020 Full text POLYMER BULLETIN

    Polyurethane hydrogels are potentially attractive materials for biomedical applications. They are able to absorb large amount of water, biological fluids or active substances, and thus, they have potential to be used as absorbents or wound-healing dressings. They are also used for the controlled release of therapeutics because of their capacity to embed biologically active agents in their water-swollen network. The presence of organofillized montmorillonite (Cloisite® 30B) in polyurethane nanocomposite hydrogels remarkably improves the swelling capability, but on the other hand slows down the release process of an active substance from the matrix. The swelling of paracetamol solution by the nanocomposite matrix and the release process of this active substance from the hydrogel were investigated using gravimetric analysis and spectroscopic method. The kinetics of both these processes were accurately analyzed by the use of Korsmeyer–Peppas and modified Hopfenberg and Weibull models. In the present paper, three different nanocomposite systems with various amounts of Cloisite® 30B were studied. The results of these studies confirm beneficial impact of the nanosize effect on the drug diffusion processes in polyurethane nanocomposite hydrogels.

  • Transverse surface waves on a cylindrical surface with coating
    • Victor Eremeev
    • Giuseppe Rosi
    • Salah Naili
    2020 Full text INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE

    We discuss the propagation of transverse surface waves that are so-called whispering-gallery waves along a surface of an elastic cylinder with coating. The coating is modelled in the framework of linearized Gurtin–Murdoch surface elasticity. Other interpretations of the surface shear modulus are given and relations to so-called stiff interface and stiff skin model are discussed. The dispersion relations are obtained and analyzed.

  • Trendy rozwojowe współczesnej telekomunikacji i wynikające z tego zagrożenia
    • Ryszard Katulski
    2020 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Telekomunikacja to dziedzina wiedzy i techniki, której przeznaczeniem jest przenoszenie informacji, z założenia z dowolnego miejsca do innego dowolnego miejsca nie tylko na kuli ziemskiej, lecz także w dostępnej nam przestrzeni. Walorem szczególnym tego jest telekomunikacja radiowa, która umożliwia tworzenie połączeń telekomunikacyjnych w sposób bezprzewodowy, za pomocą zjawiska fali radiowej, które – jak wiadomo – ma naturę pola elektromagnetycznego. Pozwala to przekazywać informacje od nadawców do odbiorców znajdujących się w stanie ruchu, a więc potencjalnie obsługiwać każdego użytkownika wyposażonego w tzw. terminal końcowy. Przy czym jest to możliwe w każdym czasie i w dowolnym miejscu. Jak widać, znaczenie telekomunikacji we współczesnym świecie trudno jest przecenić.

  • Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075
    • Kazimierz Czapczyk
    2020 Full text Materials

    The article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on the abrasive wear, which was determined as the “ball on disc” method, was analyzed. Surface topography was examined by the contact method using a profilometer. The purpose of introducing Si3N4 particles into the Ni-P layer was to increase the wear resistance of AW-7075 aluminum alloy parts with an embedded nanocomposite coating. Based on the obtained test results, it was found that the Ni-P/Si3N4 layers are more resistant to wear than the Ni-P layers and the AW-7075 alloy layers, and are a good barrier against abrasive wear at various loads and environmental conditions.

  • Trimethylamine N-oxide and the reverse cholesterol transport in cardiovascular disease: a cross-sectional study
    • Laura Bordoni
    • Joanna J. Samulak
    • Angelika K. Sawicka
    • Iwona Pelikant-Malecka
    • Adrianna Radulska
    • Lukasz Lewicki
    • Leszek Kalinowski
    • Rosita Gabbianelli
    • Robert Olek
    2020 Full text Scientific Reports

    The early atherosclerotic lesions develop by the accumulation of arterial foam cells derived mainly from cholesterol-loaded macrophages. Therefore, cholesterol and cholesteryl ester transfer protein (CETP) have been considered as causative in atherosclerosis. Moreover, recent studies indicate the role of trimethylamine N-oxide (TMAO) in development of cardiovascular disease (CVD). The current study aimed to investigate the association between TMAO and CETP polymorphisms (rs12720922 and rs247616), previously identified as a genetic determinant of circulating CETP, in a population of coronary artery disease (CAD) patients (n = 394) and control subjects (n = 153). We also considered age, sex, trimethylamine (TMA) levels and glomerular filtration rate (GFR) as other factors that can potentially play a role in this complex picture. We found no association of TMAO with genetically determined CETP in a population of CAD patients and control subjects. Moreover, we noticed no differences between CAD patients and control subjects in plasma TMAO levels. On the contrary, lower levels of TMA in CAD patients respect to controls were observed. Our results indicated a significant correlation between GFR and TMAO, but not TMA. The debate whether TMAO can be a harmful, diagnostic or protective marker in CVD needs to be continued.

  • Tripped at the Finishing Line: The Åland Islands Internet Voting Project
    • David Duenas Cid
    • Iuliia Krivonosova
    • Radu Serrano
    • Marlon Freire
    • Robert Krimmer
    • David Duenas-Cid
    2020 Full text

    The Åland Islands spent years preparing an internet voting system, to be implemented for the first time in October 2019 for Parliamentary Elections. Despite this, the project was canceled the evening before the expected release date. In this paper, we explore the causes of this failure using a two-pronged approach including Information System failure perspectives and the approach to e-voting Mirabilis, focusing on organizational elements which provoked the decision not to use the system.

  • Trouble in Paradise? Barriers to Open Innovation in Regional Clusters in the Era of the 4th Industrial Revolution
    • Marita Mcphillips
    2020 Full text Journal of Open Innovation: Technology, Market, and Complexity

    The purpose of this paper is to provide an insight into the barriers faced by clusters as open innovation intermediaries. Literature review and an empirical study were performed, involving a nation-wide survey, case studies, and in-depth interviews with cluster actors involved in open innovation activities. This article conceptually links open innovation and clusters in the context of the fourth industrial revolution, empirically identifies barriers hindering open innovation in clusters, and indicates factors that might affect the open innovation processes in networked ecosystems. The findings confirm that the perception of barriers hindering open innovation in clusters differs between clusters already implementing open innovation and those which are still not active in this area. The findings contribute to a comprehensive understanding of the potential roles of clusters as open innovation intermediaries in the context of transitioning economies. With clusters playing a role in open innovation intermediary, public support at cluster level could increase openness to cooperation not only for member companies, but all participants in the regional innovation ecosystem.

  • Trust-Based Model for the Assessment of the Uncertainty of Measurements in Hybrid IoT Networks
    • Piotr Cofta
    • Cezary Orłowski
    • Jacek Lebiedź
    2020 Full text SENSORS

    The aim of this paper is to introduce a NUT model (NUT: network-uncertainty-trust) that aids the decrease of the uncertainty of measurements in autonomous hybrid Internet of Things sensor networks. The problem of uncertainty in such networks is a consequence of various operating conditions and varied quality of measurement nodes, making statistical approach less successful. This paper presents a model for decreasing the uncertainty through the use of socially inspired metaphors of reputation, trust, and confidence that are the untapped latent information. The model described in the paper shows how the individual reputation of each node can be assessed on the basis of opinions provided by other nodes of the hybrid measurement network, and that this method allows to assess the extent of uncertainty the node introduces to the network. This, in turn, allows nodes of low uncertainty to have a greater impact on the reconstruction of values. The verification of the model, as well as examples of its applicability to air quality measurements are presented as well. Simulations demonstrate that the use of the model can decrease the uncertainty by up to 55% while using the EWMA (exponentially weighted moving average) algorithm, as compared to the reference one.

  • Tuning the extraction properties of ionogel-coated Solid-phase microextraction fibers based on the solvation properties of the ionic liquids
    • Kateryna Yavir
    • Karolina Konieczna
    • Łukasz Marcinkowski
    • Adam Kloskowski
    2020 SEPARATION AND PURIFICATION TECHNOLOGY

    A silica-based network was used to immobilize ionic liquid-based ionogels and applied as a fiber coating forsolid-phase microextraction (SPME). The ionogels were prepared by a sol–gel process, using two ionic liquids,triethylsulfonium bis(trifluoromethylsulfonyl)imide ([Set3][TFSI]) and 1-butyl-1-methylpiperidinium bis(tri-fluoromethylsulfonyl)imide ([C4C1Pip][TFSI]), as well as their equimolar mixture. Methyltrimethoxysilane wasused as the sol–gel precursor, and trifluoroacetic acid as a reaction catalyst.The fabricated ionogel fibers were evaluated as sorbent coating in headspace SPME combined with gaschromatography with barrier ionization discharge detection for volatile organic compounds (VOCs). The fibersshowed a high affinity to aromatic VOCs, yielding good sensitivity and precision. Then, the developed methodwas applied to the analysis of aqueous samples.During the study, the main extraction parameters, i.e., salt concentration, extraction time, and temperature,were optimized for maximum fiber sorption and to maximize the enrichment factors. The average limits ofdetection were found to be 0.15 μg L−1, 0.40 μg L−1, and 0.07 μg L−1, and the enrichment factors were in the25700–61000, 33200–84700, and 29100–96500 ranges for [Set3], [C4C1Pip] and [Set3/C4C1Pip], respectively.The single fiber and fiber-to-fiber reproducibilities were below 11.2% and 30.6%, respectively. The results of thiswork suggest the possibility of fabricating selected extractants based on the physicochemical properties of theionic liquids and target analytes.

  • Two kinds of oxygen vacancies in lithium titaniate doped with copper as detected by EPR
    • Marcin Łapiński
    • Lidia Piekara-Sady
    • Robert Kozioł
    • Wojciech Sadowski
    • Barbara Kościelska
    2020 SOLID STATE SCIENCES

    Lithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure and morphology are characterized by X-ray Diffraction (XRD), X-ray Photoemission Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). Spin Hamiltonian parameters describing Zeeman and hyperfine interaction for 63Cu2+ ions were obtained from EPR spectra simulations. The spectra are characteristic for (Cu-VO)0 close-associate pairs consisting of copper replacing Ti4+ ion and an adjacent doubly ionized oxygen vacancy. These oxygen vacancies serve as charge compensators for the substituting copper ions. However, there are additional narrow EPR signals at g = 2.004 in all samples, including the sample of LiTi2O4 without dopant. These signals are ascribed to single-electron trapped oxygen vacancies VO●. Superconductivity was not confirmed down to 4.2 K by magnetic measurements in all samples studied.

  • Tworzenie wartości wspólnej w uniwersytecie
    • Elżbieta Karwowska
    2020

    Problemem badawczym jest brak definicji pojęcia i modelu teoretycznego tworzenia wartości wspólnej w uniwersytecie, który jest przeszkodą dla przeprowadzenia dyskursu naukowego zmierzającego do zbadania jej możliwości oraz zasadności. Lepsze zrozumienie możliwości i zasadności tworzenia wartości wspólnej w uniwersytecie stworzy zaś nową przestrzeń do opracowania narzędzi wspomagających rozwijanie społecznej odpowiedzialności uniwersytetu. Celem rozprawy jest zdefiniowanie pojęcia oraz zbadanie możliwości i zasadności tworzenia wartości wspólnej w uniwersytecie. Aby osiągnąć przyjęty cel rozprawy, w pierwszej kolejności rozpoznano, jak rozumiane było dotąd pojęcie CSV w kontekście społecznej odpowiedzialności uniwersytetu. Następnie zaproponowano model tworzenia wartości wspólnej w uniwersytecie (CSVU, Creating Shared Value by the University) oraz zdefiniowano to pojęcie w oparciu o zaproponowany model. Kolejnym krokiem było zbadanie możliwości oraz zasadności tworzenia wartości wspólnej w uniwersytecie z perspektywy uczelni oraz z perspektywy jej otoczenia: administracji publicznej oraz biznesu. Eksploracja możliwości i zasadności CSVU z perspektywy uczelni nastąpiła za pomocą analizy tematycznej danych jakościowych zebranych za pomocą wywiadów z reprezentantami uczelni. Możliwość i zasadność CSVU z perspektywy administracji publicznej zbadano na podstawie analizy dokumentów i aktów prawnych, regulujących społeczną odpowiedzialność uczelni i ich relacje z otoczeniem społecznym i gospodarczym. Możliwość i zasadność CSVU z perspektywy biznesu zbadano zaś na podstawie analizy raportów z badań wtórnych, dotyczących opinii przedsiębiorców na temat współpracy z uczelniami. Rezultatem przeprowadzonych analiz jakościowych jest zidentyfikowanie szeregu uwarunkowań, a także szans i zagrożeń, które wpływają na możliwość i zasadność tworzenia wartości wspólnej w uniwersytecie. Wyniki przeprowadzonych badań mają również walor utylitarny, dzięki rekomendacjom w formie listy, która stanowi praktyczne wytyczne dla uniwersytetów, zainteresowanych tworzeniem wartości wspólnej.

  • Two-step mechanism of J-domain action in driving Hsp70 function
    • Bartlomiej Tomiczek
    • Wojciech Delewski
    • Łukasz Nierzwicki
    • Milena Stolarska
    • Igor Grochowina
    • Brenda Schilke
    • Rafal Dutkiewicz
    • Marta A. Uzarska
    • Szymon Ciesielski
    • Jacek Czub
    • Elizabeth Craig
    • Jaroslaw Marszalek
    2020 Full text PLoS Computational Biology

    J-domain proteins (JDPs), obligatory Hsp70 cochaperones, play critical roles in protein homeostasis. They promote key allosteric transitions that stabilize Hsp70 interaction with substrate polypeptides upon hydrolysis of its bound ATP. Although a recent crystal structure revealed the physical mode of interaction between a J-domain and an Hsp70, the structural and dynamic consequences of J-domain action once bound and how Hsp70s discriminate among its multiple JDP partners remain enigmatic. We combined free energy simulations, biochemical assays and evolutionary analyses to address these issues. Our results indicate that the invariant aspartate of the J-domain perturbs a conserved intramolecular Hsp70 network of contacts that crosses domains. This perturbation leads to destabilization of the domain-domain interface—thereby promoting the allosteric transition that triggers ATP hydrolysis. While this mechanistic step is driven by conserved residues, evolutionarily variable residues are key to initial JDP/Hsp70 recognition—via electrostatic interactions between oppositely charged surfaces. We speculate that these variable residues allow an Hsp70 to discriminate amongst JDP partners, as many of them have coevolved. Together, our data points to a two-step mode of J-domain action, a recognition stage followed by a mechanistic stage.

  • Tynki - wykonywanie i pielęgnacja
    • Maciej Niedostatkiewicz
    • Tomasz Majewski
    2020 Full text Inżynier Budownictwa

    W artykule przedstawiono podstawowe wymagania jakie powinny być zachowane podczas realizacji oraz późniejszej eksploatacji tynków tak aby jak najdłużej zachowac je w stanie wysokiej sprawności technicznej

  • Udział Biblioteki Politechniki Gdańskiej w procesie umiędzynarodowiania uczelni
    • Urszula Szybowska
    2020 Full text Pismo PG

    Umiędzynarodowienie szkolnictwa wyższego definiowane jest zasadniczo jako podejmowanie studiów na zagranicznych uczelniach oraz udział w międzynarodowych projektach badawczych i szkoleniowych. Umiędzynarodowienie szkół wyższych jest jednym z elementarnych wskaźników, które określają dziś rozwój nauki i szkolnictwa wyższego. Biblioteka PG na różnych polach wspiera uczelnię w procesie internacjonalizacji. Strategia rozwoju usług Biblioteki PG funkcjonującej w międzynarodowym środowisku opiera się zasadniczo na trzech filarach: dostosowaniu swoich zbiorów i usług do potrzeb użytkowników zagranicznych, uczestniczeniu w programie Erasmus+ oraz dynamicznym rozwijaniu współpracy z organizacjami międzynarodowymi.