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Gdańsk University of Technology

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Publications from the year 2017

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  • Regionalizacja zbiorowego transportu pasażerskiego w Polsce
    • Krzysztof Grzelec
    • Olgierd Wyszomirski
    2017 Full text Autobusy. Technika, Eksploatacja, Systemy Transportowe

    W artykule przedstawiono problem regionalizacji zbiorowego transportu pasażerskiego w Polsce. Celem artykułu jest zaprojektowanie odpowiedniego modelu organizacyjno-zarządczego tego transportu oraz do-stosowanego do niego mechanizmu finansowania działalności przewozowej. W strukturze artykułu wyodrębniono w kolejności części poświęcone procesowi regionalizacji transportu pasażerskiego, funkcjonowaniu transportu regionalnego w wybranych krajach Unii Europejskiej, funkcjonowaniu transportu regionalnego w Polsce w świetle wojewódzkich planów transportowych oraz kierunkom restrukturyzacji transportu regionalnego w Polsce. W ramach ostatniej części zaprezentowano rozważania na temat przesłanek powołania zarządu transportu regionalnego jako podmiotu organizującego i zarządzającego usługami transportu regionalnego oraz finansowania działalności zintegrowanego transportu regionalnego.

  • Regression points in non-intrusive polynomial chaos expansion method and D-optimal design
    • Katarzyna Szepietowska
    • Benoit Magnain
    • Izabela Lubowiecka
    • Eric Florentin
    2017 Machine Dynamics Research

    The paper addresses selected issues of uncertainty quantification in the modelling of a system containing surgical mesh used in ventral hernia repair. Uncertainties in the models occur e.g. due to variability of abdominal wall properties among others. In order to include them, a non-intrusive regression-based polynomial chaos expansion method is employed. Its accuracy depends on the choice of regression points. In the study a relation between error of mean, standard deviation, 95th percentile and location of regression points is investigated on the models of implants with a single random variable. This approach is compared with a classic choice of points based on the D-optimality criterion.

  • Regulacja aktywności syntazy glukozamino-6-fosforanu z Candida albicans – badania metodami obliczeniowymi
    • Aleksandra Miszkiel
    2017 Full text

    Niniejsza praca przedstawia wyniki badań, prowadzonych metodami obliczeniowymi, poświęconych enzymowi syntazie GlcN-6-P pochodzącemu z drożdży C. albicans. Enzym ten odpowiedzialny jest między innymi za biosyntezę kluczowych składników ściany komórkowej grzybów i bakterii, ma również wpływ na regulację metabolizmu glukozy. Przedstawione badania stanowią jeden z etapów poszukiwania molekularnego mechanizmu inhibicji, której eukariotyczna syntaza GlcN-6-P podlega pod wpływem swego fizjologicznego inhibitora, UDP-GlcNAc. Wyjaśnienie tego mechanizmu może mieć więc duże znaczenie nie tylko dla poszukiwań chemoterapeutyków przeciwgrzybowych, ale również w leczeniu cukrzycy typu II. Porównanie modeli statycznych domeny izomerazowej pochodzącej z C. albicans w stanie wolnym i ze związanym UDP-GlcNAc nie wykazuje istotnych różnic, tak więc podejrzewa się, iż proces inhibicji wiąże się ze zmianami w dynamicznych właściwościach cząsteczki. Prezentowane badania oparte są na analizach porównawczych dynamiki molekularnej struktur bez i ze związanym inhibitorem. Wykazały one istotne różnice w ruchliwości specyficznych fragmentów porównywanych struktur. W szczególności dotyczy to ważnych z funkcjonalnego punktu widzenia regionów, które mogą być odpowiedzialne za zmiany aktywności enzymu zachodzące pod wpływem związania inhibitora. W oparciu o te obserwacje, wysunięta została hipoteza dotycząca mechanizmu inhibicji.

  • Regulacja osi toru kolejowego metodami geodezyjnymi
    • Ernest Pilarski
    • Adrian Studziński
    • Jacek Szmagliński
    2017

    W rozdziale przedstawiono prace pomiarowe dotyczące wybranego odcinka toru w celu obliczenia poprawek do jego regulacji.

  • Relacyjność strukturalna w modelach jakości usług
    • Anna Zielińska
    2017 Studia Ekonomiczne Regionu Łódzkiego

    W opracowaniu zaprezentowano przegląd kluczowych modeli jakości usług a następnie zaproponowana została autorska koncepcja klasyfikacji tych modeli w ujęciu relacyjnym.

  • Relation of the polymorphism of cyp51A sequence and the susceptibility of Aspergillus fumigatus isolates to triazoles determined by commercial gradient test (Etest) and by reference methods
    • Urszula Nawrot
    • Beata Sulik-tyszka
    • Ewelina Kurzyk
    • Martyna Mroczyńska
    • Katarzyna Włodarczyk
    • Marta Wróblewska
    • Grzegorz Basak
    • Anna Brillowska-Dąbrowska
    2017 Acta Biochimica Polonica

    The aim of this study was to evaluate the accuracy of commercial gradient test (Etest) in the detection of triazole resistant Aspergillus fumigatus isolates using reference microdilution methods and the analysis of sequences of the cyp 51A gene. The study was performed on twenty clinical isolates which were identified as Aspergillus fumigatus based on the DNA sequences of the ITS1-2 fragment of ribosomal DNA and the β-tubulin gene, out of them seventeen isolates showed wild -type cyp51A sequence and three were positive for the mutation TR34/L98H. All isolates were tested for the susceptibility to itraconazole (ITZ), voriconazole (VOR) and posaconasole (POS) using microdilution methods, according to EUCAST and CLSI protocols, as well as using Etest. The results of microdilution and Etests were analysed separately according to clinical breakpoints (CBP) defined by EUCAST version 7.0 and epidemiological cut off values (ECV). Etest as well as reference methods excellently recognised the WT isolates, which were susceptible to all tested triazoles, regardless of the method and CBP or ECV criteria used. The Etest recognized three non-WT isolates as resistant or intermediately sensitive to ITZ and POS and one as resistant to VOR. The categorical concordance between Etests and EUCAST and Etests and the CLSI method ranged from 90 to 100%. The interpretation of the results obtained from routine A. fumigatus Etests requires great caution. The use of the confirmative examinations with reference AST methods as well as with molecular tests is recommended.

  • Relationships between Trust and Collaborative Culture in The Context of Tacit Knowledge Sharing
    • Wioleta Kucharska
    2017 Full text Journal of Entrepreneurship, Management and Innovation

    The literature review presents a lot of theoretical and empirical evidence that Trust affects Collaborative Culture. The opposite also proves to be true: Collaborative Culture influences Trust. The main hypothesis presented in this paper says that both these factors are strongly correlated and modify each other. This study examines the mutual relationship of the said variables in the context of Tacit Knowledge Sharing based on a research conducted among 514 Polish professionals performing different functions and having various experience in managing projects in the construction industry. The results obtained in the course of the study indicate that there is not only a strong correlation between Trust and Collaborative Culture but both of them have a strong influence on Tacit Knowledge Sharing. The main managerial implication of the study is the importance of stimulating the growth of both Collaborative Culture and Trust. Receiving a strong synergy effect will make it possible to leverage Tacit Knowledge Sharing as an agent contributing to a company’s Performance.

  • Relevance of the EU Structural Funds’ Allocation to the Needs of Combating Air Pollution in Poland. Analysis of the Operational Programmes of Regions Threatened With Critical Air Pollution from Distributed Energy Sources
    • Marcin Włodarski
    • Justyna Martyniuk-Pęczek
    2017

    Recent years, the European Environmental Agency, has been reporting air quality parameters in Poland, as the poorest among all the EU countries. Despite of adoption of the EU legislation on energy efficiency and energy performance of buildings, existing legal solutions occur insufficient in reducing air pollution in Polish regions. Lack of an effective schemes supporting complex thermal renovation of buildings, exchange of inefficient boilers, developing district heating based on clean and renewable fuels results in severe health problems and 40 000 of premature deaths related to air pollution. Availability of the EU structural funds may become a tremendous opportunity, especially for the residential sector, to conduct a massive scale modernization. Nevertheless, lack of a coordinated action involving all levels of governance may put the opportunity at risk. The article aims to answer the question on the readiness of the regional governments to effectively implement energy efficiency measures mitigating the problem of air pollution. Second objective is to analyse whether the Regional Operational Programmes allocating the ERDF funds to support specific development needs of the regions, have been constructed in a way that properly addresses the problems related to energy performance of residential buildings.

  • Relevance of Urban Freight Transport Modelling Towards the Challenges of Urban Freight Policy
    • Daniel Kaszubowski
    2017

    The main objective of this paper is to investigate how recent trends in urban freight transport analysis and modelling are related to urban freight measures set out in Gdynia’s 2016 Sustainable Urban Mobility Plan. Building on the literature a review framework was defined including 1) stakeholders, 2) descriptors, 3) objectives and 4) solution approach applied in freight modelling efforts. It was clear that the implementation of SUMP's objectives will require a significant effort to improve data resources and planning techniques. However, this process could be supported by modifying the city’s existing transport model and identifying the restocking behaviour of commercial stakeholders

  • Reliability and efficiency of pollution removal during long-term operation of a one-stage constructed wetland system with horizontal flow
    • Krzysztof Jóźwiakowski
    • Piotr Bugajski
    • Zbigniew Mucha
    • Włodzimierz Wójcik
    • Andrzej Jucherski
    • Maria Nastawny
    • Tadeusz Siwiec
    • Andrzej Mazur
    • Radmir Obroślak
    • Magdalena Gajewska
    2017 Full text SEPARATION AND PURIFICATION TECHNOLOGY

    The paper presents the results of a study of the reliability and efficiency of pollutant removal during long term operation of a one-stage constructed wetland system with horizontal flow. The flow rate of the wastewater treatment plant was 1.2 m3·d-1 during the research period. Physical and chemical analyses of raw wastewater and treated effluent were carried out in the years 1997–2010 (14 years). During this study period, 56 series of analyses were performed and 112 wastewater samples were collected. The average efficiencies of BOD5 (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand) and TSS (Total Suspended Solids) removal in the investigated facility during the 14 years of its operation were respectively: 84.7%, 80.9%, and 62.4%. The average values of these parameters in the treated wastewater were significantly lower than the values deemed acceptable by relevant regulations in Poland. The reliabilities of the wastewater treatment plant, based on the Weibull reliability theory for acceptable values of pollution parameters in the effluent of the treatment plant, were as follows: BOD5 – 92%, COD – 98%, TSS – 90%. The conducted analysis showed that the operational reliability of the one-stage horizontal subsurface flow constructed wetland (HSFCW) over the operation period was insufficient according to the Polish standards. Improvement of the reliability of the analyzed system by introduction of additional purification elements, such as irrigated biological beds or a constructed wetland with vertical wastewater flow, was recommended.

  • Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
    • Karol Winkelmann
    • Patrycja Jakubowska
    • Barbara Sołtysik
    2017 Full text

    The study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon is given in the form of a structural response surface (RSM methodology), approximated by an ANOVA table with directional sampling (DS) points. Four design limit states are considered: stress limit criterion for a natural load combination, criterion for an accidental combination (one-sided cable snap), vertical and horizontal translation criteria. According to these cases the HLRF reliability index β is used for structural safety assessment. The RSM approach is well suited for the analysis – it is numerically efficient, not excessively time consuming, indicating a high confidence level. Given the problem conditions, the seismic excitation is shown the sufficient trigger to the loss of load-bearing capacity or stability of the tower.

  • Reliability of nitrogen removal processes in multistage treatment wetlands receiving high-strength wastewater
    • Ewa Wojciechowska
    • Magdalena Gajewska
    • Arkadiusz Ostojski
    2017 ECOLOGICAL ENGINEERING

    reatment wetlands have been proved to be more effective than conventional treatment processes in case of high-strength wastewater containing high concentrations of ammonium nitrogen and recalcitrant organic matter. In this study nitrogen removal processes and reliability of nitrogen removal at two identical pilot-scale multistage treatment wetlands (MTWs) receiving real, non-synthetic wastewater were discussed. The wastewater discharged to pilot-scale subsurface flow MTWs contained high ammonium nitrogen concentrations and limited biodegradable organic matter (OM) concentrations. One of the pilot MTWs was fed with landfill leachate (LL) and another one with reject water from sewage sludge centrifugation (RW). In the first season of operation both MTWs reached very high (95–99%) efficiency of total nitrogen (TN) removal, which was explained by adsorption to the substrate. In the later period, TN was removed in a sequence of nitrification and denitrication processes with lower efficiency (40–86%). The denitrification process was the limiting one at the LL treating site because of too low carbon supply. Still, during the whole investigation period TN outflow concentrations were at the level that allows for co-treatment of the effluent in municipal wastewater treatment plants without risk for biological treatment processes. In 90% of samples TN concentration was below 200 mg/l and in 60% of samples it was below 145 mg/l.

  • Reliable low-cost surrogate modeling and design optimisation of antennas using implicit space mapping with substrate segmentation
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2017 Full text IET Microwaves Antennas & Propagation

    Abstract: In this work, a reliable methodology for fast simulation-driven design optimisation of antenna structures is proposed. The authors’ approach exploits implicit space mapping (ISM) technology. To adopt it for handling antenna structures, they introduce substrate segmentation with separate dielectric permittivity value assigned for each segment as ISM preassigned parameters. At the same time, the coarse model for space mapping is established by reducing discretisation level of the EM analysis of the antenna structure at hand. Further, the proposed approach is generalised to permit execution of ISM in case of dielectric resonator antennas (DRAs), which is realised by segmentation of the DR and appropriate assignment of permittivity values. The discussed methodology is demonstrated through optimisation of a bandwidth-enhanced patch antenna and a triangular DRA. Comparison with state-of-the-art surrogate-assisted design methods, here, frequency and output space mapping, as well as conventional optimisation using pattern search, is also provided.

  • Renewable Resources for Polyurethanes and Polyurethane Composites: A Review
    • Józef Haponiuk
    • Aleksander Hejna
    • Łukasz Piszczyk
    • Janusz Datta
    • Krzysztof Formela
    2017

    Each year, more than two million tons of polyurethane is produced in the EU by reacting isocyanates with polyols made from fossil fuel. In addition, there are appreciable quantities of petroleum based functional additives applied in the industry nowadays for both polyols and polyurethane materials. It is therefore of key importance to develop sustainable economically viable polyols with enhanced functionalities, and thereby reducing the need for polyols and additives made from non-renewable fossil fuel. By basing polyurethanes on biomaterials, the carbon footprint is reduced, and using biomass waste/byproducts will further improve the environmental profile. Many studies show that materials from renewable can almost fully substitute their petrochemical analogs. Also polyurethane industry shows increasing interest in polyols derived from renewable resources. Relatively new materials from renewable resources that can be incorporated into polyurethane technology are glycerol and its polymeric form. Incorporation of these compounds is related to the production of biofuels, based on fatty acid methyl esters. Glycerol is a by-product in biodiesel production, 100 kg of glycerol is obtained for each tone of fuel. According to European Biodiesel Board, consumption of biodiesel in EU will exceeds yearly 15 Mt, what gives 1.5 Mt of waste glycerol to utilize which can be polymerized and successively used in PU. This work, based on the literature and personal research, presents the status of knowledge about application in the synthesis of polyurethanes of renewable raw materials and waste materials, mainly derived from natural oils, waste glycerol from biodiesel production and biomass.

  • Report for the Short Term Scientific Mission within COST Action FP1101: development of the in-field sensor for estimation of fracture toughness and shear strength by measuring cutting forces
    • Jakub Sandak
    • Kazimierz Orłowski
    • Tomasz Ochrymiuk
    • Anna Sandak
    • Mariapaola Riggio
    2017 Full text International Wood Products Journal

    Knowledge on the fracture properties of materials is essential to assure structural integrity and proper design of mechanical connections in timber constructions. Measurement of this property is, however, a very challenging task. The linear fracture mechanics is usually used for its assessment assisted with experimental data acquired by means of various techniques, usually of destructive nature. The cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The original methodology of simultaneous determination of the fracture toughness and of the shear yield strength on the basis of cutting forces was adopted here for timber characterisation. The set of experimental data was generated in a simple cutting test by using slightly modified out-the-shelf instrumentation. The resulting data are the slope and intercept of linear regression function of cutting forces versus chip thickness estimated for five European wood species. Both parameters are usable for computation of fracture toughness and shear yield strength in the shear plane, separately for two anatomical directions of wood. The simplicity and reliability of this method provides wide range of practical applications, including structural health assessment of the timber structures.

  • Report on investigation of turbine blade from main engine turbocharger 420.34 from M/V "Nordstraum"
    • Krzysztof Krzysztofowicz
    • Grzegorz Gajowiec
    2017

    Wykonano badania pęknięcia na łopatce turbiny turbodoładowania silnika głównego. Ustalono, ze przyczyną pęknięcia była korozja międzykrystaliczna.

  • Requirements, modifications and methods of mechanical testing of bone cement – literature review
    • Marcin Wekwejt
    • Beata Świeczko-Żurek
    • Marek Szkodo
    2017 Full text European Journal of Medical Technologies

    The Aim of the paper is to show the basic requirements for the bone cement, its modifications in terms of physical, mechanical and biological properties and testing methods. This publication is intended to be a source of systematized basic knowledge regarding the modified bone cement.

  • Research and analysis of high-speed data transmission radio link designed for maritime environment
    • Paweł Tomasz Kosz
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Sadowski
    • Jacek Stefański
    2017 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    In these article the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio link in laboratory conditions was also subscribed.

  • Research and Analysis of High-Speed Data Transmission Radio Link Designed for Maritime Environment
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Paweł Tomasz Kosz
    • Jacek Stefański
    • Jarosław Sadowski
    2017

    In these article, the realization of digital radio link for high-speed data transmission was presented. Its concept and practical realization, using USRP devices from National Instruments, were described. Developed software for generation and reception of digital signals in baseband, including description of modulation types, and time and frequency synchronization mechanisms, was presented. Moreover, an operation of designed radio link in laboratory conditions was also subscribed.

  • RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
    • Ryszard Jasiński
    2017

    Starting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of increase of resistance of cold oil flow in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump working chambers with oil and reducing volumetric efficiency. Starting of cooled hydraulic pump in low temperatures may occur when pump is supplied with oil of the same temperature as the surroundings or the oil is warmed to higher temperature than the ambient temperature. During start-up of a hydraulic pump in thermal shock conditions, parts warm up in a nonuniform way, due to varying material and shape properties. This causes change of clearances between the co-operating elements and may lead to faulty operation of hydraulic pump or to its break-down. Experimental tests of hydraulic pumps in low ambient temperatures were conducted in the Laboratory of Hydraulics of the Faculty of Mechanical Engineering of the Gdańsk University of Technology. Tested pumps were placed in the low temperature chamber in which – 25 ºC temperature can be reached. The components were supplied with the warm mineral oil in the temperature ranging from 20 ºC to 60 ºC. In order to investigate of the heating process, temperature sensors were placed in moving and fixed parts of the pumps. In the research three types of pumps were considered: two axial piston pumps of different designs and one radial piston pump. It was proved, that in thermal shock conditions some malfunctions may occur, especially with large temperature difference between oil and pump. Experimental research of various hydraulic pumps operating in low ambient temperatures, undertaken by the author, allows to answer the question how the effective clearance changes in such conditions and what parameters does it depend on. To evaluate parameters for correct start-up of hydraulic pumps in thermal shock conditions, author uses and recommends two methods: analytical and computer simulation.