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Gdańsk University of Technology

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Publications from the year 2018

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  • Expert systems in assessing the construction process safety taking account of the risk of disturbances
    • Agata Siemaszko
    • Anna Jakubczyk-Gałczyńska
    • Beata Grzyl
    2018 Full text Scientific Journal of the Military University of Land Forces

    The objective of the paper is to present the issue of safety manage-ment during the construction process. Threats in the form of disturb-ances may occur in the preparatory phase, during the execution of the construction project and also during its operational use. The arti-cle presents the concept of applying the methodology based, among others, on Learning Bayesian Networks, Artificial Neural Networks and Support Vector Machine, which can be used for building a sys-tem for diagnostic and decision-making support at each stage of the construction process. The use of expert systems when it comes to making choices related to construction issues can bring many bene-fits to decision-makers, as it reduces the risk of taking a wrong deci-sion, and, thus, increases the construction process safety.

  • Explicit Size-Reduction-Oriented Design of a Compact Microstrip Rat-Race Coupler Using Surrogate-Based Optimization Methods
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    • Leifur Leifsson
    • Xiaosong Du
    • Yonatan Tesfahunegn
    2018

    In this paper, an explicit size reduction of a compact rat-race coupler implemented in a microstrip technology is considered. The coupler circuit features a simple topology with a densely arranged layout that exploits a combination of high- and low-impedance transmission line sections. All relevant dimensions of the structure are simultaneously optimized in order to explicitly reduce the coupler size while maintaining equal power split at the operating frequency of 1 GHz and sufficient bandwidth for return loss and isolation characteristics. Acceptable levels of electrical performance are ensured by using a penalty function approach. Two designs with footprints of 350 mm and 360 mm2 have been designed and experimentally validated. The latter structure is characterized by 27% bandwidth. For the sake of computational efficiency, surrogate-based optimization principles are utilized. In particular, we employ an iterative construction and re-optimization of the surrogate model involving a suitably corrected low-fidelity representation of the coupler structure. This permits rapid optimization at the cost corresponding to a handful of evaluations of the high-fidelity coupler model.

  • Export diversification and economic development: A dynamic spatial data analysis
    • Roberto Basile
    • Aleksandra Parteka
    • Rosanna Pittiglio
    2018 Full text Review of International Economics

    This paper contributes to the empirical literature on the relationship between “export variety” (export diversification) and economic development by relaxing the assumption of cross-country independence and allowing for spatial diffusion of shocks in observed and unobserved factors. Export variety is measured for a balanced panel of 114 countries (1992–2012) using very detailed information on their exports (HS 6-digit product level). The estimation results of a dynamic spatial panel data model confirm the relevance of spatial network effects in export diversification: indirect effects (spatial spillovers) strongly reinforce direct effects, while spatial proximity to large countries accelerates the diversification process. In about 10 years the whole space–time diffusion of the diversification shock is widely completed. We reveal that the long-run spillover impact from European countries is much higher than from other countries such as the United States, Japan, or the BRICS (Brazil, Russia, India, China, and South Africa).

  • Extended phase diagram of RNiC2 family: Linear scaling of the Peierls temperature
    • Marta Roman
    • Judyta Strychalska-Nowak
    • Tomasz Klimczuk
    • Kamil Kolincio
    2018 Full text PHYSICAL REVIEW B

    Physical properties for the late-lanthanide-based RNiC2 (R = Dy, Ho, Er, and Tm) ternary compounds are reported. All the compounds show antiferromagnetic ground state with the Néel temperature ranging from 3.4 K for HoNiC2 to 8.5 K for ErNiC2. The results of the transport and galvanomagnetic properties confirm a charge density wave state at and above room temperature with transition temperatures TCDW = 284, 335, 366, and 394 K for DyNiC2, HoNiC2, ErNiC2, and TmNiC2, respectively. The Peierls temperature TCDW scales linearly with the unit cell volume. A similar linear dependence has been observed for the temperature of the lock-in transition T1 as well. Beyond the intersection point of the trend lines, the lock-in transition is no longer observed. In this Rapid Communication we demonstrate an extended phase diagram for the RNiC2 family.

  • Extending Continuous Integration with Post-mortem Debug Automation of Unhandled Exceptions Occurred in Kernel or User Mode Applications
    • Henryk Krawczyk
    • Dawid Zima
    2018 Advances in Intelligent Systems and Computing

    The paper proposes extension of the Continuous Integration practices with debug automation of unhandled exceptions. Goal of this improvement is to reduce the amount of redundant work when inspecting hundreds of failed tests from possibly the same reason, and to decrease time necessary to provide a fix to the codebase. The suitable CI infrastructure is proposed and an automatic method how to eliminate duplicated bugs is discussed. Also an example of such automation in the Windows operating system is presented.

  • Extracting concepts from the software requirements specification using natural language processing
    • Jarosław Kuchta
    • Pritiben Padhiyar
    2018

    Extracting concepts from the software require¬ments is one of the first step on the way to automating the software development process. This task is difficult due to the ambiguity of the natural language used to express the requirements specification. The methods used so far consist mainly of statistical analysis of words and matching expressions with a specific ontology of the domain in which the planned software will be applicable. This article proposes a method and a tool to extract concepts based on a grammatical analysis of requirements written in English without the need to refer to specialized ontology. These concepts can be further expressed in the class model, which then can be the basis for the object-oriented analysis of the problem. This method uses natural language processing (NLP) techniques to recognize parts of speech and to divide sentences into phrases and also the WordNet dictionary to search for known concepts and recognize relationships between them.

  • Extracting functional groups of ALLINI to design derivatives of FDA‐approved drugs: Inhibition of HIV‐1 integrase
    • Umesh Kalathiya
    • Monikaben Padariya
    • Maciej Bagiński
    2018 BIOTECHNOLOGY AND APPLIED BIOCHEMISTRY

    HIV‐1 integrase (IN) is crucial for integration of viral DNA into the host genome and a promising target in development of antiretroviral inhibitors. In this work, six new compounds were designed by linking the structures of two different class of HIV‐1 IN inhibitors (active site binders and allosteric IN inhibitors (ALLINIs)). Among newly designed compounds, INRAT10b was found most potent HIV‐1 IN inhibitor considering different docking results. To further validate protein–ligand interactions obtained from dockings, molecular dynamics simulations were performed for inhibitor raltegravir and INRAT10b placed either at active site or allosteric site of HIV‐1 IN (monomer or dimer). Results suggest that both raltegravir and INRAT10b were interacting with residue Gln62, Gly140, Ile141, and Ser147. However, INRAT10b interacts better with high H‐bond occupancy, which can explain the strong binding affinity of INRAT10b than raltegravir with the HIV‐1 IN protein. Subdomains rearrangements in HIV‐1 IN suggest that the C‐terminal and catalytic core domains develop their closeness in the presence of ligand. More significantly, the newly designed derivatives represent novel compounds targeting catalytic site and C‐terminal (protein–protein interaction) domains simultaneously. And we also propose INRAT10b as a promising lead compound for the development of potent HIV‐1 IN inhibitors.

  • Fabrication and Characterization of Flexible Medical-Grade TPU Filament for Fused Deposition Modeling 3DP Technology
    • Agnieszka Haryńska
    • Iga Gubańska
    • Justyna Kucińska-Lipka
    • Helena Janik
    2018 Full text Polymers

    The possibility of using additive manufacturing (AM) in the medicine area has created new opportunities in health care. This has contributed to a sharp increase in demand for 3D printers, their systems and materials that are adapted to strict medical requirements. We described herein a medical-grade thermoplastic polyurethane (S-TPU) which was developed and then formed into a filament for Fused Deposition Modeling (FDM) 3D printers during a melt-extrusion process. S-TPU consisting of aliphatic hexamethylene 1,6-diisocyanate (HDI), amorphous ,!-dihydroxy(ethylene-butylene adipate) (PEBA) and 1,4 butandiol (BDO) as a chain extender, was synthesized without the use of a catalyst. The filament (F-TPU) properties were characterized by rheological, mechanical, physico-chemical and in vitro biological properties. The tests showed biocompatibility of the obtained filament as well as revealed no significant effect of the filament formation process on its properties. This study may contribute to expanding the range of medical-grade flexible filaments for standard low-budget FDM printers.

  • Fabrication and photoactivity of ionic liquid–TiO2 structures for efficient visible-light-induced photocatalytic decomposition of organic pollutants in aqueous phase
    • Anna Gołąbiewska
    • Marta Paszkiewicz-Gawron
    • Aleksandra Sadzińska
    • Wojciech Lisowski
    • Ewelina Grabowska
    • Adriana Zaleska-Medynska
    • Justyna Łuczak
    • Anna Golabiewska
    2018 Full text Beilstein Journal of Nanotechnology

    To investigate the effect of the ionic liquid (IL) chain length on the surface properties and photoactivity of TiO2, a series of TiO2 microspheres have been synthesized via a solvothermal method assisted by 1-methyl-3-octadecylimidazolium chloride ([ODMIM][Cl]) and 1-methyl-3-tetradecylimidazolium chloride ([TDMIM][Cl]). All as-prepared samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), scanning transmission microscopy (STEM) and the Brunauer–Emmett–Teller (BET) surface area method, whereas the photocatalytic activity was evaluated by the degradation of phenol in aqueous solution under visible light irradiation (λ > 420 nm). The highest photoefficiency (four times higher than pristine TiO2) was observed for the TiO2 sample obtained in the presence of [TDMIM][Cl] for IL to TiO2 precursor molar ratio of 1:3. It was revealed that interactions between the ions of the ionic liquid and the surface of the growing titanium dioxide spheres results in a red-shift of absorption edge for the IL–TiO2 semiconductors. In this regard, the direct increase of the photoactivity of IL–TiO2 in comparison to pristine TiO2 was observed. The active species trapping experiments indicated that O2•− is the main active species, created at the surface of the IL–TiO2 material under visible-light illumination, and is responsible for the effective phenol degradation.

  • Fabrication, structural and electrical properties of Sr(V,Nb)O 3-δ perovskite materials
    • Tadeusz Miruszewski
    • Bartosz Kamecki
    • Marcin Stanisław Łapiński
    • Jakub Karczewski
    2018 MATERIALS CHEMISTRY AND PHYSICS

    The SrV1-xNbxO3-δ materials with different niobium content in perovskite B-sublattice were prepared by a solid-state reaction process. The microstructure and phase compositions of obtained samples were analyzed by the X-ray diffraction technique (XRD) and scanning electron microscopy (SEM). The electrical conductivity of samples was measured by a DC 4-wire method in range of 100–600 °C in different gas conditions. The oxidation state of the niobium and vanadium cations in the structure was determined by the X-ray photoelectron spectroscopy (XPS). The obtained results were discussed and analyzed in comparison to the previous literature reports and defect chemistry models.

  • Facile formation of self-organized TiO2 nanotubes in electrolyte containing ionic liquid - ethylammonium nitrate and their remarkable photocatalytic properties
    • Anna Pancielejko
    • Paweł Mazierski
    • Wojciech Lisowski
    • Adriana Zaleska-Medynska
    • Klaudia Kosek
    • Justyna Łuczak
    2018 Full text ACS Sustainable Chemistry & Engineering

    The oriented TiO2 nanotube arrays (NTs) are identified as a stable, active and recyclable photocatalytic surface. However, their photoactivity is strictly depended on morphology (especially length), which could be controlled by anodic oxidation parameters, including electrolyte properties. To control the morphology, were successfully synthesized a series of NTs by a novel approach where ionic liquid (IL), ethylammonium nitrate [EAN][NO3], was used as an addition to an organic electrolyte. Using scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, diffuse reflectance UV-Vis spectroscopy and photoluminescence spectroscopy we are able to show how electrolyte composition influence nanotubes surface properties and photocatalytic activity. It was found that the change in the amount of [EAN][NO3] in electrolyte used for anodization in the range from 0.05 to 1.0 wt.% affected dynamic viscosity, conductivity and surface tension of electrolyte and finally alter morphology of formed nanotubes resulting in a proportional increase of the outer diameter and tube length from 105 to 140 nm and from 6.0 to 8.1 µm, respectively. The highest photoactivity (achieving high reaction rate constant, equal to k = 0.0941 min-1) and wettability was found for the sample prepared in the electrolyte containing 0.05 wt.% of [EAN][NO3] revealing the improved ability to light photoabsorption and suppression of recombination rate. It turned out that IL_NTs surface became more hydrophobic when stored in air ambience over 7 weeks after fabrication with approximately 20 – 52°. The increase of the contact angle from 9.3 to 13.1° with elongation of the tube diameter from 107 to 140 nm was also noted.

  • Fading Characteristics for Dynamic Body-to-Body Channels in Indoor and Outdoor Environments
    • Kenan Turbić
    • Sławomir Ambroziak
    • Luis M. Correia
    2018

    This paper presents an analysis of the fading characteristics in dynamic body-to-body channels, based on measurements performed at 2.45 GHz in indoor and outdoor environments. The statistical analysis of the small- and large-scale fading shows that the Nakagami Distribution is the best model for the former and the Log-Normal one for the latter. An important influence of body shadowing on the small-scale fading characteristics is observed, where the average amount of fading (fading merit) for the case when either of the users is obstructing the direct path is up to 2.56 times higher than when the direct path is unobstructed. The influence of the environment is also important, where small-scale fading is more severe in the indoor environment than in the outdoor one; 1.88 times higher average amount of fading and 3.81 dB lower K-factor are observed.

  • Fading Modeling in Maritime Container Terminal Environments
    • Manuel M. Ferreira
    • Sławomir Ambroziak
    • Filipe D. Cardoso
    • Jarosław Sadowski
    • Luis M. Correia
    2018 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY

    In this paper, an analytical model for slow and fast fading effects in maritime container terminals is derived, from fitting distributions to the results of measurements performed in an actual operational environment. The proposed model is composed of a set of equations, enabling to evaluate fading statistical distribution parameters for different system and environments conditions, as a function of frequency, base station antenna height, and average height of container stacks in a deepwater container terminal. The model’s coefficients were obtained from a multivariate linear regression of the fitted distributions parameters, allowing to evaluate the different statistical distribution parameters with a negligible mean error and a standard deviation of the error less than 0.65 dB. It is observed that a good fitting is obtained for slow fading with the Lognormal Distribution, the standard deviation ranging in [1.40, 4.81] dB, while fast fading is well modeled by the Nakagami Distribution with the standard deviation ranging in [0.43, 1.26]. Hence, in a conservative perspective, values of 5 and 1.3 dB are proposed to characterize slow and fast fading, respectively.

  • Failure mode prediction for composite structural insulated panels with MgO board facings
    • Łukasz Smakosz
    • Ireneusz Kreja
    2018 Full text

    Sandwich panels are readily used in civil engineering due to their high strength to weight ratio and the ease and speed of assembly. The idea of a sandwich section is to combine thin and durable facings with a light-weight core and the choice of materials used allows obtaining the desired behaviour. Panels in consideration consist of MgO (magnesium oxide) board facings and expanded polystyrene core and are characterized by immunity to biological corrosion, a high thermal insulation and a relatively low impact on environment. Customizing the range of panels to meet market needs requires frequent size changes, leading to different failure modes, which are identified in a series of costly full-scale laboratory tests. A nonlinear numerical model was created with a use of a commercial ABAQUS code and a user-defined procedure, which is able to reproduce observed failure mechanisms; its parameters were established on the basis of small-scale tests and numerical experiments. The model was validated by a comparison with the results of the full-scale bending and compression tests. The results obtained were in satisfactory agreement with the test data.

  • Failure Monitoring and Condition Assessment of Steel-Concrete Adhesive Connection Using Ultrasonic Waves
    • Magdalena Rucka
    2018 Full text Applied Sciences-Basel

    Adhesive bonding is increasingly being incorporated into civil engineering applications. Recently, the use of structural adhesives in steel-concrete composite systems is of particular interest. The aim of the study is an experimental investigation of the damage assessment of the connection between steel and concrete during mechanical degradation. Nine specimens consisted of a concrete cube and two adhesively bonded steel plates were examined. The inspection was based on the ultrasound monitoring during push-out tests. Ultrasonic waves were excited and registered by means of piezoelectric transducers every two seconds until the specimen failure. To determine the slip between the steel and concrete a photogrammetric method was applied. The procedure of damage evaluation is based on the monitoring of the changes in the amplitude and phase shift of signals measured during subsequent phases of degradation. To quantify discrepancies between the reference signal and other registered signals, the Sprague and Gears metric was applied. The results showed the possibilities and limitations of the proposed approach in diagnostics of adhesive connections between steel and concrete depending on the failure modes.

  • Failure of cold-formed beam: How does residual stress affect stability?
    • Paweł Michał Bielski
    • Oskar Wysocki
    • Jacek Czyżewicz
    2018

    In machine industry, stresses are often calculated using simple linear FEM analysis. Occasional failures of elements designed in such a way require recomputation by means of more sophisticated methods, eg. including plasticity and non-linear effects. It usually leads to investigation of failure causes and improvement of an element in order to prevent its unwanted behavior in the future. The study presents the case where both linear and non-linear analyses show some load capacity reserve and do not justify failure occurring in reality. Some non-standard causes are pointed out, including residual stress of a leading role.

  • Family business experience and the probability of starting a venture: gender differences in Poland
    • Paweł Ziemiański
    2018 Journal for East European Management Studies

    The aim of this study is to analyse whether the experience of working in a family member’s business is related differently to the assessed probabilities of men and women starting their own new venture in the future. The research is conducted on a sample of 334 Polish undergraduate students. Poland is an efficiency-driven European economy with a substantial gender gap in entrepreneurship. The results obtained indicate that the relationship studied differs significantly across gender. Women assess their probability of starting their own ventures as lower than men do. This difference is only found among those with experience gained in a family member’s business. Men and women without such experience do not differ in their assessments. Our findings indicate that the mere inclusion of women in a family’s business activities may not be sufficient to reduce the gender gap.

  • Fasady przeszklone
    • Katarzyna Zielonko-Jung
    2018 Architektura-Murator

    Podstawową rola człowieka ą użytkową okna w budynku jest zapewnienie dostępu światła dziennego i widoku z wnętrza na otoczenie. Zastosowanie powierzchni szklanych wiąże się jednak również z innymi procesami użytkowania budynku. Artykuł skupia się na termicznych i świetlnych właściwościach szkła i zasadach ich wykorzystania w kształtowaniu komfortowego środowiska wnętrza przy użyciu możliwie najmniejszych nakładów energetycznych. Omówione różne typy szklenia ze wskazaniem w jakich rodzajach budynków mogą znaleźć zasotosowanie

  • Fasady zabytkowe
    • Anita Jaśkiewicz-Sojak
    • Dorota Hryszkiewicz-Kahlau
    2018 Architektura-Murator

    Konserwacja zabytków nie jest zamkniętą księgą niezmiennych praw i zasad. Zmienia się wraz z kolejnymi epokami.I nie jest zbiorem sztywnych reguł, które dają się zastosować bez refleksji i wiedzy. W każdym przypadku prac prowadzonych na konkretnej fasadzie konieczne jest postawienie diagnozy właściwej dla rozpatrywanego przypadku i umiejętne znalezienie środków zaradczych w tej konkretnej jednostkowej sytuacji. Trzeba umieć ocenić wartości zabytku i rozważyć, co będzie dla niego najlepsze. Nie można się przy tych działaniach obejść bez specjalistów – konserwatorów zabytków. W zabytkowej fasadzie powinniśmy widzieć nie tylko zamysł twórcy – dzieło architektoniczne z kompozycją elewacji. Dla nas, żyjących na początku XXI wieku, to również zabytkowa substancja – autentyczny materiał, z którego dawni budowniczowie wznieśli obiekt, świadek przeszłości,wytworzony rękami dawnych rzemieślników. Dlatego warto mieć zawsze na uwadze, że prace prowadzone na zabytkowych fasadach nie służą jedynie poprawie estetyki, lecz przede wszystkim zachowaniu przeszłości. Po pierwsze nie szkodzić. Pamiętajmy, że w konserwacji zabytków (tak jak i w innych dziedzinach życia) umiar zawsze jest pożądany. Lepiej zrobić mniej i zostawić zabytek przyszłym pokoleniom (które będą dysponować lepszymi technologiami konserwatorskimi i nowoczesnymi, mniej ingerującymi zabiegami, których może nawet jeszcze nie potrafimy sobie wyobrazić), niż za dużo i zniszczyć cenny ślad przeszłości.

  • Fast, sensitive and reliable multi-residue method for routine determination of 34 pesticides from various chemical groups in water samples by using dispersive liquid – liquid microextraction coupled with gas chromatography – mass spectrometry
    • Maciej Tankiewicz
    • Marek Biziuk
    2018 Full text ANALYTICAL AND BIOANALYTICAL CHEMISTRY

    A simple and efficient dispersive liquid-liquid microextraction technique (DLLME) was developed by using a mixture of two solvents: 40 μL of tetrachlorethylene (extraction solvent) and 1.0 mL of methanol (disperser solvent), which was rapidly injected with a syringe into 10mL ofwater sample. Some important parameters affecting the extraction efficiency, such as type and volume of solvents, water sample volume, extraction time, temperature, pH adjustment and salt addition effect were investigated. Simultaneous determination of 34 commonly used pesticides was performed by using gas chromatography coupled with mass spectrometry (GC-MS). The procedure has been validated in order to obtain the highest efficiency at the lowest concentration levels of analytes to fulfill the requirements of regulations onmaximumresidue limits. Under the optimumconditions, the linearity range was within 0.0096–100 μg L−1. The limits of detection (LODs) of the developed DLLME-GC-MS methodology for all investigated pesticides were in the range of 0.0032 (endrin)–0.0174 (diazinon) μg L−1 and limits of quantification (LOQs) from 0.0096 to 0.052 μg L−1. At lower concentration of 1 μg L−1 for each pesticide, recoveries ranged between 84%(tebufenpyrad) and 108% (deltamethrin) with relative standard deviations (RSDs) (n = 7) from 1.1% (metconazole) to 11% (parathion-mehtyl). This methodology was successfully applied to check contamination of environmental samples. The procedure has proved to be selective, sensitive and precise for the simultaneous determination of various pesticides. The optimized analytical method is very simple and rapid (less than 5 min).