Publications Repository - Gdańsk University of Technology

Page settings

polski
Publications Repository
Gdańsk University of Technology

Show publications from the year

Publications from the year 2017

Show all
  • lLmondo globale
    • Luciano Segreto
    2017

    Lo globalizzazione e i BRICS - Lo svilu the economic development of East Asia- The commodities market

  • Load Testing of GFRP Composite U-Shape Footbridge
    • Łukasz Pyrzowski
    • Mikołaj Miśkiewicz
    • Jacek Chróścielewski
    • Krzysztof Wilde
    2017 Full text

    The paper presents the scope of load tests carried out on an innovative shell composite footbridge. The tested footbridge was manufactured in one production cycle and has no components made from materials other than GFRP laminates and PET foam. The load tests, performed on a 14-m long structure, were the final stage of a research program in the Fobridge project carried out in cooperation with: Gdańsk University of Technology (leader), Military University of Technology in Warsaw, and ROMA Co. Ltd.; and co-financed by NCBR. The aim of the tests was to confirm whether the complex U-shape sandwich structure behaves correctly. The design and technological processes involved in constructing this innovative footbridge required the solving of many problems: absence of standards for design of composite footbridges, lack of standardized material data, lack of guidelines for calculation and evaluation of material strength, and no guidelines for infusion of large, thick sandwich elements. Obtaining answers during the design process demanded extensive experimental tests, development of material models, validation of models, updating parameters and extensive numerical parametric studies. The technological aspects of infusion were tested in numerous trials involving the selection of material parameters and control of the infusion parameters. All scientific validation tests were successfully completed and market assessment showed that the proposed product has potential applications; it can be used for overcoming obstacles in rural areas and cities, as well as in regions affected by natural disasters. Load testing included static and dynamic tests. During the former, the span was examined at 117 independent measurement points. The footbridge was loaded with concrete slabs in different configurations. Their total weight ranged from 140 kN up to 202 kN. The applied load at the most heavily loaded structural points caused an effect from 89% to 120%, compared to the load specified by standards (5 kN/m2 ). Dynamic tests included standard actions (walking, running, synchronous jumps) as well as aggressive tests, all designed to confirm the usability of the footbridge. The performed trials allowed the identification of the modal and damping parameters of the structure. The designated first natural frequency with a value of 7.8 Hz confirmed the correctness of the U-shape cross-section design due to its significant structural rigidity.

  • Load Tests of the Movable Footbridge Over the Port Canal in Ustka
    • Mikołaj Miśkiewicz
    • Łukasz Pyrzowski
    2017

    The paper presents the acceptance tests carried out on the open footbridge over the port canal in the Port of Ustka. The steel footbridge construction is created by a single pylon to which a movable truss span is suspended with a theoretical span of 52.3 m. The studies about load test of the object included static and dynamic extortion and measurements. In static tests the ballast was of pallets with concrete blocks. Dynamic studies were carried out by extortions induced by a group of pedestrians in various combinations. Structural behavior was recorded using geodetic techniques - displacement and settlement of supports, strain gages - strain and force in lines and accelerometers - acceleration. The measured parameters were consistent with the theoretical values. Tests ended with a positive result that allows putting the footbridge in use with the design assumptions.

  • Load-settlement characteristics of piles working in a group
    • Adam Krasiński
    • Tomasz Kusio
    2017

    Load-settlement characteristic (Q-s) of an axially loaded pile can be empirically determined from a static pile load test or on the basis of calculations using, e.g. transfer functions or numerical methods (FEM). The transfer functions method usually rely on empirical data, i.e. the function parameters are determined on the basis of numerous pile test results. Thus this method takes into account pile installation technology and is more reliable than FEM, where a proper simulation of the pile installation is yet to be achieved. Load-settlement characteristics are very useful for structural calculations of the pile foundation. However, Q-s characteristics refer to a single pile. Moreover, field load tests are usually performed on single piles and hardly ever on pile groups or even just several piles. And yet most foundations are supported by a larger number of piles (group of piles) and it is commonly known that the working conditions of a pile in a group are different than that of a single pile. The described problem is analyzed numerically and empirically using model tests. The results of comparative computations and model tests of CFA and SDP piles working individually and in a group of nine piles are presented and discussed. Some conclusions regarding Q-s characteristics of piles working in a group are formulated

  • Local buckling of thin-walled channel member flange made of aluminum alloy
    • Czesław Szymczak
    • Marcin Kujawa
    2017

    The paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential energy. The equation solution leads to the critical buckling stress and assessment of the number of half-waves in linear elastic range of the member material. Taking into account these results the analytical formula of the critical buckling stress in nonlinear elastic range is established using the tangent modulus theory and the Ramberg-Osgood stress-strain relationship. Finally the analytical results for simply supported members are compared with the FEM solutions and good agreement is observed.

  • Local Mesh Deformation for accelerated parametric studies based on the Finite Element Method
    • Martyna Mul
    • Grzegorz Fotyga
    • Michał Mrozowski
    2017

    This paper presents an approach for enhancing the efficiency of two-dimensional Finite Element Method analysis in parametric studies or optimisation process of microwave components. The new approach involves local mesh deformation applied near the elements that are modified during computations. Since in the proposed approach the topology of the mesh remains unchanged, a new mesh does not have to be generated from scratch when the geometry changes. In effect, substantial reduction of time taken by parametric studies or optimization of microwave components can be achieved, especially if the technique is combined with local Model-Order Reduction, called macromodeling.

  • Local mesh morphing technique for parametrized macromodels in the finite element method
    • Martyna Mul
    • Grzegorz Fotyga
    • Michał Mrozowski
    2017

    This paper presents a novel approach for enhancing the efficiency of the design process of microwave devices by means of the finite element method. It combines mesh morphing with local model order reduction (MOR) and yields parametrized macromodels that can be used to significantly reduce the number of variables in the FEM system of equations and acceleration of computer simulation. A projection basis for local reduction is generated only once, for the original geometry and the associated mesh. The projection basis generated for the nominal design is subsequently used for updated geometries and morphed meshes thereby allowing for reducing the numerical cost and the computational time of parametric studies or the optimization process. The performance of the proposed approach is demonstrated on a two dimensional example.

  • Localization and Orientation of Xanthophylls in a Lipid Bilayer
    • Grudziński Wojciech
    • Łukasz Nierzwicki
    • Renata Welc
    • Emilia Reszczynska
    • Rafal Luchowski
    • Jacek Czub
    • Wiesław I. Gruszecki
    • Emilia Reszczyńska
    2017 Full text Scientific Reports

    Xanthophylls (polar carotenoids) play diverse biological roles, among which are modulation of the physical properties of lipid membranes and protection of biomembranes against oxidative damage. Molecular mechanisms underlying these functions are intimately related to the localization and orientation of xanthophyll molecules in lipid membranes. In the present work, we address the problem of localization and orientation of two xanthophylls present in the photosynthetic apparatus of plants and in the retina of the human eye, zeaxanthin and lutein, in a single lipid bilayer membrane formed with dimyristoylphosphatidylcholine. By using fluorescence microscopic analysis and Raman imaging of giant unilamellar vesicles, as well as molecular dynamics simulations, we show that lutein and zeaxanthin adopt a very similar transmembrane orientation within a lipid membrane. In experimental and computational approach, the average tilt angle of xanthophylls relative to the membrane normal is independently found to be ~40 deg, and results from hydrophobic mismatch between the membrane thickness and the distance between the terminal hydroxyl groups of the xanthophylls. Consequences of such a localization and orientation for biological activity of xanthophylls are discussed.

  • Lokalizacja osób w środowisku promu pasażerskiego z wykorzystaniem ultra szerokopasmowego interfejsu radiowego
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Sadowski
    2017 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W niniejszym artykule przedstawiono badania efektywności lokalizowania poruszających się osób w środowisku promu pasażerskiego stosując pomiar czasu propagacji ultraszerokopasmowego sygnału radiowego UWB (Ultra-Wide Band) pomiędzy węzłami odniesienia i terminalem ruchomym. Opisano zbudowane stanowisko badawcze oraz uzyskane wyniki pomiarów przeprowadzonych w warunkach rzeczywistych.

  • Lokaty bankowe jako narzędzie gromadzenia oszczędności na emeryturę
    • Elżbieta Damps-Lewińska
    2017 Full text Zeszyty Naukowe Politechniki Poznańskiej. Organizacja i Zarządzanie

    W artykule poruszona została problematyka zabezpieczenia finansowego gospodarstwa domowego, w okresie po przejściu na emeryturę jego członków. Opracowanie prezentuje wyniki analizy możliwości wykorzystania instrumentu rynku finansowego, jakim jest lokata bankowa, dla poprawy sytuacji materialnej gospodarstwa domowego, które znajduje się już w fazie nieaktywności zarobkowej. Do przeprowadzenia stosownych obliczeń, wykorzystane zostały dane statystyczne publikowane przez Główny Urząd Statystyczny oraz Narodowy Bank Polski. Przy dokonywaniu analiz, pod uwagę został wzięty 15-letni okres badawczy, obejmujący lata 2000-2014. Natomiast metodą badawczą, była analiza zgromadzonych danych, przy zastosowaniu metod matematycznych oraz analizy literatury przedmiotu.

  • Long range molecular dynamics study of interactions of the eukaryotic glucosamine-6-phosphate synthase with fructose-6-phosphate and UDP-GlcNAc
    • Aleksandra Miszkiel
    • Marek Wojciechowski
    2017 Full text JOURNAL OF MOLECULAR GRAPHICS & MODELLING

    Glucosamine-6-phosphate synthase (EC 2.6.1.16) is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5 diphospho Nacetyl- d-glucosamine (UDP-GlcNAc), is an essential substrate for assembly of bacterial and fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which makes of it a potential target for anti-fungal, anti-bacterial and anti-diabetic therapy. The crystal structure of isomerase domain from human pathogenic fungus Candida albicans has been solved recently but it doesn’t reveal the molecular mechanism details of inhibition taking place under UDP-GlcNAc influence, the unique feature of eukaryotic enzyme. The following study is a continuation of the previous research based on comparative molecular dynamics simulations of the structures with and without the enzyme’s physiological inhibitor (UDP-GlcNAc) bound. The models used for this study included fructose-6-phosphate, one of the enzyme’s substrates in its binding pocket. The simulation results studies demonstrated differences in mobility of the compared structures. Some amino acid residues were determined, for which flexibility is evidently different between the models. Importantly, it has been confirmed that the most fixed residues are related to the inhibitor binding process and to the catalysis reaction. The obtained results constitute an important step towards understanding of the inhibition that GlcN-6-P synthase is subjected by UDP-GlcNAc molecule

  • Long-term performance and microbial characteristics of the anammox-enriched granular sludge cultivated in a bench-scale sequencing batch reactor
    • Dominika Sobotka
    • Agnieszka Tuszyńska
    • Przemysław Kowal
    • Sławomir Ciesielski
    • Krzysztof Czerwionka
    • Jacek Mąkinia
    2017 BIOCHEMICAL ENGINEERING JOURNAL

    The anammox-enriched granular sludge was successfully formed during the long-term biogranulation experiment lasting over 330 days. The cultivation was conducted at 30 ◦C in a 10-L sequencing batch reactor (SBR) fed with synthetic medium containing ammonia, nitrite and trace elements. The properties of the developed granules were investigated in terms of the biomass activity (including the growth rate of anammox bacteria), size distribution of the granules as well as nitrogen removal performance and pathways. The compositions of the microbial communities in the inoculum sludge and ultimate granules were compared using the metagenomic analysis. The mean particle size of the biomass increased from 290 m (inoculum sludge) to 728 m (ultimate granules). The overall nitrogen removal rate (NRR) and specific anammox activity (SAA) reached themaximumvalue of 5.3 kg Nm−3 d−1 and 1.6 kg NkgVSS−1 d−1, respectively. In the matured granules, Planctomycetes were the most abundant phylum (aprox. 44% of total 16S rRNA reads), exclusively represented by Candidatus Brocadia. Based on the 16S rRNA reads frequency derived from Planctomycetes in the total metagenomic library and volatile suspended solids (VSS) concentrations of the inoculum sludge and ultimate granules, the observed specific growth rate of anammox bacteria was estimated at 0.14 d−1 over the entire study period.

  • Low Cost Hexacopter Autonomous Platform for Testing and Developing Photogrammetry Technologies and Intelligent Navigation Systems
    • Paweł Burdziakowski
    2017 Full text

    Low-cost solutions for autonomous aerial platforms are being intensively developed and used within geodetic community. Unmanned aerial vehicles are becoming very popular and widely used for photogrammetry and remote sensing applications. Today’s market offers an affordable price components for unmanned solution with significant quality and accuracy growth. Every year market offers a new solutions for autonomous platforms with better technical specifications. Commercial drones for amateurs are widely offered and presents a quality and accuracy not available in past few years. In this paper an autonomous open source low cost haxacopter system for photogrammetry and intelligent navigation technologies evaluation is being presented. The system was designed and assembled for technologies testing and for educational purposes. The drone is based only on open source hardware and software. All components are based on open source and commercial of the shelf products. That approach to the drones construction provides a many capabilities to test, implement and execute new algorithms, solutions and tasks. Providing basic configuration tools system enables students to safely perform elementary setup and testing. An advanced configurations system tool and open source structure enables to execute advanced scientific test and research. Paper presents results of designed process, system configuration and specification, technical issues that was being solved during test flights and practical research results.

  • Low frequency of itraconazole resistance found among avian Aspergillus fumigatus isolates
    • Urszula Nawrot
    • Alina Wieliczko
    • Katarzyna Włodarczyk
    • Ewelina Kurzyk
    • Anna Brillowska-Dąbrowska
    2017

    Aspergillus fumigatus is the most frequent etiological factor of invasive aspergillosis in human as well as animals, including birds. Aspergillosis caused by drug-resistant strains poses a significant therapeutic issue, especially if resistance pattern includes insensitivity to triazoles, i.e. drugs recommended for the primary therapy purposes. Majority of resistant isolates hold the TR34/L98H mutation (34 bp tandem repeats in the promotor region and single point mutations of cyp 51A gene resulting in the substitution of leucine for histidine in lanosterol 14 alpha-demethylase). It is suggested that the overuse of some fungicides in agriculture contribute to the selection of resistant mutants. The avian farms seems to be places of higher risk of contamination and subsequent infection caused by resistant Aspergillus fumigatus strains.

  • Low speed permanent magnet synchronous generator for vertical axis wind turbine
    • Grzegorz Andrzej Kostro
    • Michał Michna
    • Filip Kutt
    • Mieczysław Ronkowski
    2017

    The paper presents design process and tests of a prototype low speed permanent magnet synchronous generator (PMSG) dedicated for the innovative vertical-axis wind turbine. The rated data of the designed generator are following: power - 15 kVA, voltage - 400 V (Y), rotation speed - 93.75 rpm. The design assumptions, chosen results of the design process and experimental tests of the prototype PMSG are presented. The considered PMSG can be used in low-power wind plants applied for vessels (ships, yachts) and stationary prosumers power installations. The whole project realization (concept, design, engineering documentation, building and testing) of the prototype low-speed PMSG was commissioned by company ALU ECO Sp. o.o. Gdansk, and co-financed by the Polish Agency for Enterprise Development (PAED).

  • Low-Coherence Interferometric Fiber-Optic Sensors with Potential Applications as Biosensors
    • Marzena Hirsch
    • Daria Majchrowicz
    • Paweł Wierzba
    • Matthieu Weber
    • M. Bechelany
    • Małgorzata Szczerska
    2017 Full text SENSORS

    Fiber-optic Fabry-Pérot interferometers (FPI) can be applied as optical sensors, and excellent measurement sensitivity can be obtained by fine-tuning the interferometer design. In this work, we evaluate the ability of selected dielectric thin films to optimize the reflectivity of the Fabry-Pérot cavity. The spectral reflectance and transmittance of dielectric films made of titanium dioxide (TiO2) and aluminum oxide (Al2O3) with thicknesses from 30 to 220 nm have been evaluated numerically and compared. TiO2 films were found to be the most promising candidates for the tuning of FPI reflectivity. In order to verify and illustrate the results of modelling, TiO2 films with the thickness of 80 nm have been deposited on the tip of a single-mode optical fiber by atomic layer deposition (ALD). The thickness, the structure, and the chemical properties of the films have been determined. The ability of the selected TiO2 films to modify the reflectivity of the Fabry-Pérot cavity, to provide protection of the fibers from aggressive environments, and to create multi-cavity interferometric sensors in FPI has then been studied. The presented sensor exhibits an ability to measure refractive index in the range close to that of silica glass fiber, where sensors without reflective films do not work, as was demonstrated by the measurement of the refractive index of benzene. This opens up the prospects of applying the investigated sensor in biosensing, which we confirmed by measuring the refractive index of hemoglobin and glucose.

  • Low-coherence sensors with nanolayers for biomedical sensing
    • Mateusz Ficek
    • Daria Majchrowicz
    • Katarzyna Karpienko
    • Julia Milewska
    • Bartłomiej Dec
    • Paweł Wierzba
    • Przemysław Struk
    • Małgorzata Szczerska
    2017

    In this paper, we describe the fiber optic low-coherence sensors using thin film. We investigated their metrological parameters. Presented sensors were made with the use of standard telecommunication single mode optical fiber (SMF28). Different materials were applied to obtain thick layers, such as boron doped diamond, silver and gold. The thickness of layers used in the experiments ranged from 100 nm to 300 nm. Measurements were performed with broadband source operating at central wavelength 1300 nm. The measurement signal was acquired by an optical spectrum analyzer. Measured signal was analyzed in the spectrum domain. Any change of the phase difference between interfering beams reflected from the sensor head depends on measurand occurred in the spectrum of the measurement signal. We obtain the visibility value of the measured signal equal to 0.97.

  • Low-cost Adsorbents Derived from Agricultural By-products/Wastes for Enhancing Contaminant Uptakes from Wastewater: A Review
    • Mohamed Sulyman
    • Jacek Namieśnik
    • Andrzej Gierak
    2017 Full text POLISH JOURNAL OF ENVIRONMENTAL STUDIES

    A major threat to the comfort of human life has been imposed by increased industrialization and urbanization. The generation and disposal of huge amounts of toxic materials and pollutants have heavily contaminated our environment. Some Organics such as synthetic dyes (SD) and heavy metals (HM) are becoming increasingly prevalent as the most dangerous pollutants in soil and surface water environments. They are causing great concern worldwide due to their toxicity to many life forms

  • Low-energy interactions related to atmospheric and extreme conditions
    • Sylwia Ptasinska
    • Małgorzata Śmiałek-Telega
    • Aleksandar Milosavljević
    • Bhalamurugan Sivaraman
    2017 EUROPEAN PHYSICAL JOURNAL D

    This Topical Issue, entitled “Low-Energy Interactions Related to Atmospheric and Extreme Conditions”, showcases a collection of eighteen articles that reported recent theoretical and experimental findings pertaining to the following topics: – low-energy interactions of charged particles (electrons [1–7], protons [8], positrons [9]), and photons [10] with atoms and molecules of biological [1–4,7,8], astrochemical [10], industrial, and environmental [5,6,9] interest; – molecular evolution of astrochemical ices [11–13]; – planetary atmospheric physics [14]; – atmospheric pressure photoionization and fragmentation of organic and inorganic aerosols [15]; – processes and applications of atmospheric pressure plasmas in astrochemical [16,17] and biomedical fields [17,18].

  • Low-frequency tripping characteristics of residual current devices
    • Stanisław Czapp
    • Krzysztof Dobrzyński
    • Jacek Klucznik
    • Zbigniew Lubośny
    2017

    Fast development of various types of converters makes their utilization in industry and in domestic installations very common. Due to converters, an earth fault current waveform in modern circuits can be distorted or its frequency can be different than 50/60 Hz. Frequency of earth fault (residual) current influences tripping of residual current devices which are widely used in low voltage systems. This paper presents the behaviour of residual current devices when residual current of frequency lower than 50 Hz flows. The results of the analysis have shown that many of commonly used residual current devices are not able to detect residual current when its frequency is significantly lower than 50 Hz. Thus, protection against electric shock may not be effective.