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Gdańsk University of Technology

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Publications from the year 2017

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  • Extending touch-less interaction with smart glasses by implementing EMG module
    • Tomasz Kocejko
    • Krzysztof Czuszyński
    • Jacek Rumiński
    • Adam Bujnowski
    • Artur Poliński
    • Jerzy Wtorek
    2017

    In this paper we propose to use temporal muscle contraction to perform certain actions. Method: The set of muscle contractions corresponding to one of three actions including “single-click”, “double-click” “click-n-hold” and “non-action” were recorded. After recording certain amount of signals, the set of five parameters was calculated. These parameters served as an input matrix for the neural network. Two-layer feedforward neural network with one hidden layer of 200 neurons was applied to classify gestures based on the input matrix. Results: The network was trained using the dataset consisted of 43 samples and then tested on the 34 samples dataset. All gestures from the test set were correctly classified.

  • Extraction with environmentally friendly solvents
    • Justyna Płotka-Wasylka
    • Małgorzata Rutkowska
    • Katarzyna Owczarek
    • Marek Tobiszewski
    • Jacek Namieśnik
    2017 Full text TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    The ever-increasing demand for determining compounds at low concentration levels in complex matrices requires a preliminary step of analytes isolation/enrichment in order to employ a detection technique characterized by high sensitivity at low LOQ. Sample preparation is considered as crucial part of analytical procedures. Previously the parameter of “greenness” is as important as selectivity in order to avoid using harmful organic solvents in sustainable extraction techniques. These solvents can generate hazardous, toxic waste while consuming large resources volume. Developing new green solvents is one of the key subjects in Green Chemistry in order to reduce the intensity of anthropogenic activities related to analytical laboratories. A lot of new, more eco-friendly media have been employed as extractant phases. These media, besides of being more eco-friendly, provide shorter extraction times, simplicity, low cost, better selectivity in some cases. The most promising, most widely used green extraction solvents are described in this review.

  • EXTRAORDINARY RAINFALLS IN GDANSK (NORTHERN POLAND) IN THE 21ST CENTURY
    • Wojciech Szpakowski
    • Michał Szydłowski
    2017

    In the 21st century Gdansk had been affected by two rainfall events with a total precipitation amount of over 120 mm each. Rainfall parameters exceeded the regional values of the rain occurring once every 100 years. At the meteorological station of Gdansk University of Technology, July 9th 2001 was recorded 123.5 mm and July 14th 2016, 150.8 mm rainfall (within 24 hours observation period). Despite the same seasons of summer months and a duration of about 16 hours, both rains were characterised by different course and causes of their occurrence. The study compared the causes, course and consequences of these extraordinary rainfall events. In the paper the precipitation parameters were compared with the depth-duration-frequency curve (DDF curve) which were determined on the basis of actual rainfall events that occurred in the 20th century in the northern Poland. It was found that the analysed rainfalls significantly exceed the theoretical dependence, primarily due to the total amount of precipitation, which accounted for 190% of normal rain in July as well as due to the duration of the phase of the most intense rain (up to 8 hours in year 2016). The two mentioned rainfall episodes were also compared with other rain indicators. One of the rain indicators used in Poland is Chomicz's rainfall intensity 12 grade scale. This scale classifies rainfall episode as normal rain, storm, heavy storm or torrential rain. Both events are partially classified as torrential rain with grade U5. It is worth noting that the losses after the flood of 2016 were tallied many times lower than after the rainfall event in 2001. It was possible due to massive investment in storage reservoirs on both the natural water and storm sewer systems. Development of the land surface in Gdansk also takes into account the need to better retention of rainwater. It should be noted that the above two events significantly exceeded the parameters of the precipitation that occurs once in 100 years. The mentioned rainfalls occurred at an interval of only 15 years. It seems to be a proof that the climate changes must be taken into account when estimating the size of precipitation for current and future activities.

  • Fabrication and Crystal Structure of Sol-Gel Deposited BST Thin Films with Compositional Gradient
    • Dionizy Czekaj
    • Agata Lisińska-Czekaj
    • Julian Plewa
    2017 Full text ARCHIVES OF METALLURGY AND MATERIALS

    In the present research technology of compositionally graded barium strontium titanate Ba1-xSrxTiO3 thin films deposited on stainless steel substrates by sol-gel spin coating followed with thermal annealing at T = 650°C is reported. Results of thermal behavior of the sol-gel derived powders with compositions used for fabrication of graded structure (i.e. with Sr mole fraction x = 0.5, 0.4 and 0.3) are described. X-ray diffraction studies of the phase composition and crystal structure of such complex thin film configuration are given. It was found that gel powders exhibited a large total weight loss of about Δm ≈ 44-47%. Three stages of weight loss took place at temperature ranges: below T ≈ 300°C, at ΔT ≈ 300-500°C and between T = 600°C and T = 800°C. Phase analysis has shown that the dominating phase is Ba0.67Sr0.33TiO3 compound while the second phase is Ba0.7Sr0.3TiO3 or Ba0.5Sr0.5TiO3 for “up-graded” and “down-graded” structure, respectively.

  • Fabrication and photoactivity of organic-inorganic systems based on titania nanotubes and PEDOT containing redox centres formed by different Prussian Blue analogues
    • Mariusz Szkoda
    • Jacek Rysz
    • Jacek Ryl
    • Anna Lisowska-Oleksiak
    • Katarzyna Siuzdak
    2017 JOURNAL OF ALLOYS AND COMPOUNDS

    Herein, the heterojunction composed of an inorganic substrate: ordered hydrogenated titania nanotubes (H-TiO2NTs) and a deposited organic film: poly(3,4-ethylenedioxythiophene) (PEDOT) is reported. The conducting polymer is modified with different transition metal haxacyanoferrates (Mehcf), wherein as metal: copper, iron, cobalt and nickel are introduced. The presence of various metal centres provides characteristic redox activity and allows to investigate the impact of the particular Prussian Blue analogues onto the photoactivity of the p-n heterojunction. The formed composites were inspected by means of scanning electron microscopy, spectroscopic techniques, i.e. UV–Vis, Raman and Secondary Ion Mass spectrometry and using electrochemical methods. It is shown that electrochemical and photoelectrochemical performance of the so-fabricated materials is significantly affected by the nature of the redox species introduced into the PEDOT matrix.

  • Fabrication and Significant Photoelectrochemical Activity of Titania Nanotubes Modified with Thin Indium Tin Oxide Film
    • Katarzyna Siuzdak
    • Mariusz Szkoda
    • Jakub Karczewski
    • Jacek Ryl
    • Kazimierz Darowicki
    • Katarzyna Grochowska
    2017 Acta Metallurgica Sinica-English Letters

    Ordered titanium dioxide nanotubes (TiO2NTs) modified with indium tin oxide (ITO) films were obtained via magnetron sputtering, in which ITO plate was used as a target, onto the as-anodized titania support followed by the calcination process. The morphology of fabricated material with deposited oxide was investigated using scanning electron microscopy. Raman and UV–Vis spectroscopies were utilized to characterize crystalline phase and optical properties of prepared samples, whereas X-ray photoelectron spectroscopy allowed determining the binding energy of present elements. In the case of titanium, three various oxidation states were identified and also the presence of indium and tin was confirmed. The electrochemical test carried out when the sample was exposed to light allows for selection of the most photoactive material. The highest photocurrent was registered when only 5-nm ITO layer was sputtered, and it equals 256 and 133 lA cm-2 for the electrode material immersed in 0.5 M KOH and K2SO4 electrolytes, respectively, that is accordingly 3.5 and 4.4 times higher than the one observed for pristine titania. Furthermore, ITO-modified titania exhibits excellent photostability upon prolonged illumination that is of key importance for possible application in light-driven processes.

  • Facebook : zagmatwany świat relacji międzyludzkich
    • Marta Szeluga-Romańska
    2017

    Rozdział dotyczy wpływu Internetu, mediów społecznościowych na już funkcjonujące oraz dopiero tworzące się relacje między ludźmi. Odnosi się także do sposobów użycia współczesnych narzędzi komunikacji.

  • Factors determining accumulation of bisphenol A and alkylphenols at a low trophic level as exemplified by mussels Mytilus trossulus
    • Marta Staniszewska
    • Bożena Graca
    • Adam Sokołowski
    • Iga Nehring
    • Andrzej Wasik
    • Anna Jendzul
    2017 ENVIRONMENTAL POLLUTION

    The aim of the study was to investigate abiotic and biotic factors influencing the accumulation of endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-tert-octylphenol (OP) and 4- nonylphenol (NP) in mussels Mytilus trossulus from the Gulf of Gdansk (Southern Baltic). The key abiotic factor influencing BPA, OP and NP accumulation in mussels is their hydrophilicity/lipophilicity, which affects their main assimilation routes - by digestive tract for the more lipophilic OP and NP, and additionally by the gills for the less lipophilic BPA. As a result, high condition index (i.e. higher soft tissue weight) is more often correlated with high concentrations of OP and NP in mussels than with BPA. Furthermore, alkylphenols have 6e8 times greater accumulative potential than BPA. Concentration of the studied compounds was lower in females than in males following spawning, and the effect lasted longer for BPA than for alkylphenols. The influence of season and hydrological conditions on BPA, OP, NP in the mussel was more pronounced than the proximity of external sources of these compounds. An increase in water temperature in summer probably stimulated the solubility of BPA, the least lipophilic of the studied compounds, and led to increased assimilation of this compound from water (through gills). On the other hand, high OP and NP concentrations in mussels occurred in spring, which was caused by increased surface run-off and sediments resuspension.

  • FAILURE OF MAGNETIC FLUID SEALS OPERATING IN WATER: PRELIMINARY CONCLUSIONS
    • Leszek Matuszewski
    2017 Full text Polish Maritime Research

    The article analyses properties of magnetic fluid seals installed in rotary sealing no des which operate in the utility water environment. Seals of this type have been examined as a possible solution to the problem with ship manoeuvring propulsion sealing. The present analysis bases on laboratory durability tests of magnetic fluid seals expo sed to long - term utility water loads, at different water pressures and shaft revolutions. The basic seal durability criterion was the number of revolutions made by the sealing node shaft until the appearance of water tightness loss (leakage). It was found that the main factor leading to the wear of the seal is the relative speed of the magnetic fluid with respect to that of the utility water, and this process is heavily affected by the pressure acting on the seal. The reported test results are presented in the form of diagrams showing the seal durability (time until water tightness loss) as a function of rotational speed. The curves shown in the diagrams are regular, with two different rotational speed ranges: the high - speed range, when the tightness loss is relatively fast, and the low - speed range, with a clear tendency to prolong the seal lifetime. These diagrams were given the name of durability curves of the MF seal operating in water. The results of the performed tests suggest formal similarity between t he experimental data distribution concerning tightness loss processes occurring in magnetic fluid seals operating in water environment and metal fatigue processes. The article proposes a preliminary simplified durability model to describe the examined phenomenon.

  • Fake VIP Attacks and Their Mitigation via Double-Blind Reputation
    • Jerzy Konorski
    2017 Full text

    In a generic setting subsuming communication networks, resource sharing systems, and multi-agent communities, a client generates objects of various classes carrying class-dependent signatures, to which a server assigns class-dependent service quality. A Fake VIP attack consists in false declaration of a high class, with an awareness that detection of object signature at the server side is costly and so invoked reluctantly. We show that such attacks can be mitigated by a server-side double-blind repu-tation scheme. We offer a minimum-information framework for Fake VIP attacks and a stochastic analysis of a two-player Stackelberg game to find optimum attack and defense strategies, as well as to identify regions of operation where both the client and the server find the reputation scheme beneficial.

  • Fast GC as a useful tool for authenticity assessment of kiwifruit
    • Paweł Michalczuk
    • Joanna Myszka
    • Martyna Lubinska-Szczygeł
    • Anna Różańska
    • Jacek Namieśnik
    2017 Full text World Scientific News

    Kiwifruit is one of the healthiest fruits due to its high content of biologically active substances and nutrients. The most popular species of Actinidia (kiwifruit) are the Actinidia deliciosa fruits called kiwi and Actinidia chinensis commonly called golden kiwi, while the lesser known species is Actinidia arguta known as mini kiwi. Bioactivities and nutrients of Actinidia are influenced by species and cultivars. It is very important to find a way to distinguish kiwifruit samples from botanical and geographical origin. For this purpose, the possibility of application of electronic nose based on ultrafast gas chromatography for differentiation three types of kiwifruit was investigated. A set of 18 samples of kiwifruits were analyzed by fast GC e-nose. This device contains two parallel chromatography columns with different polarity connected with two flame ionization detectors (μ- FIDs). Four data analysis methods were used: discriminant function analysis (DFA), principal component analysis (PCA), soft independent modeling of class analogies (SIMCA), and statistical quality control (SQC). Application of e-nose based on fast GC system allows to effective and rapid compare of aroma profiles of three types of kiwifruits. PCA, DFA and SIMCA data analysis method were for visualization the discrimination between groups of kiwifruit species. The SQC method allowed to assess the quality of the samples. All of used chemometric methods allows for full discrimination of all groups of samples. In summary, the use of ultra-fast GC with four statistical methods can be used to discrimination of kiwifruit samples due to their botanical and geographical origins.

  • Fast multi-criterial statistical analysis and design optimization of compact microwave couplers
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2017

    —A rapid statistical analysis and yield estimation of compact microwave couplers involving multiple performance parameters has been presented. The analysis is realized using a fast surrogate model representing appropriate characteristic points of the coupler response. Because of less nonlinear dependence of the characteristic points on the structure geometry (compared to the original response, i.e., S-parameters vs. frequency), a small number of training points is necessary to setup a reliable surrogate. Our approach is demonstrated using a compact rat-race coupler and validated using direct EM-based Monte Carlo analysis. Accelerated yield optimization is also presented

  • Fate and significance of phthalates and bisphenol A in liquid by-products generated during municipal solid waste mechanical-biological pre-treatment and disposal
    • Sylwia Fudala-Książek
    • Mattia Pierpaoli
    • Aneta Łuczkiewicz
    2017 Full text WASTE MANAGEMENT

    Samples of liquid by-products generated by municipal solid waste plants (MSWPs) were tested for the presence of phthalates (PAEs) and bisphenol A (BPA). The results indicated that the wastewater generated during mechanical (sorting unit - SU) and biological (composting unit - CU) pre-treatment (MBT) of residual (mixed) solid waste is a significant source of these compounds. The concentrations of PAEs (up to 32222 lg/L) and BPA (up to 1795 lg/L) in the SU and CU wastewaters were generally higher than those in landfill leachates tested in this and other studies. To date, MBT wastewaters have been poorly studied and are usually overlooked. However, in this study, despite their relatively small quantities, they constituted an important load of ammonia (up to 1610 mg/L) and organic matter (COD up to 52980 mg/L). Thus, to apply an effective treatment, it is critical to monitor the current quality and quantity of all liquid byproducts generated at MSWPs and to prioritize the (micro)pollutants of concern.

  • Fault diagnosis of marine 4-stroke diesel engines using a one-vs-one extreme learning ensemble
    • Jerzy Kowalski
    • Bartosz Krawczyk
    • Michał Woźniak
    2017 Full text ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE

    This paper proposes a novel approach for intelligent fault diagnosis for stroke Diesel marine engines, which are commonly used in on-road and marine transportation. The safety and reliability of a ship's work rely strongly on the performance of such an engine; therefore, early detection of any type of failure that affects the engine is of crucial importance. Automatic diagnostic systems are of special importance because they can operate continuously in real time, thereby providing efficient monitoring of the engine's performance. We introduce a fully automatic machine learning-based system for engine fault detection. For this purpose, we monitor various signals that are emitted by the engine, and we use them as an input for a pattern classification algorithm. This action is realized by an ensemble of Extreme Learning Machines that work in a decomposition mode. Because we address 14 different faults and a correct operation mode, we must handle a 15-class problem. We tackle this task by binarization in one-vs-one mode, where each Extreme Learning Machine is trained on a pair of classes. Next, Error-Correcting Output Codes are used to reconstruct the original multi-class task. The results from experiments that were conducted on a real-life dataset demonstrate that the proposed approach delivers superior classification accuracy and a low response time in comparison with a number of state-of-the-art methods and thus is a suitable choice for a real-life implementation on board a ship.

  • FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
    • Tomasz Stefański
    • Tomasz Dziubak
    2017

    A discrete Green's function (DGF) approach to couple disjoint domains in the finite-difference time-domain (FDTD) grid is developed. In this method, total-field/scattered-field (TFSF) FDTD domains are associated with simulated objects whereas the interaction between them is modeled with the use of the DGF propagator. Hence, source and scatterer are simulated in separate domains and updating of vacuum cells, being of little interest, can be avoided. The simulation scenarios consisting of (i) disjoint domains separated by a spatial distance and (ii) a sub-domain embedded in the main grid are considered. In the developed method, the field radiated by an FDTD domain is computed as a convolution of DGF with equivalent current sources measured over two displaced Huygens surfaces in the scattered-field zone. Therefore, the computed electromagnetic field is compatible with the FDTD grid and can be applied as an incident wave in a coupled TFSF domain. The developed method of diakoptics can be generalized for simulations of FDTD domains requiring nonlinear or multiphysics modeling with interaction between them computed with the use of DGF propagators.

  • Feasibility study of a Raman spectroscopic route to drug detection
    • Maciej Wróbel
    • Soumik Siddhanta
    • Małgorzata Szczerska
    • Janusz Smulko
    • Ishan Barman
    2017

    We present an surface-enhanced Raman spectroscopy (SERS) approach for detection of drugs of abuse in whole human blood. We utilize a near infrared laser with 830 nm excitation wavelength in order to reduce the influence of fluorescence on the spectra of blood. However, regular plasmon resonance peak of plasmonic nanoparticles, such as silver or gold fall in a much lower wavelength regime about 400 nm. Therefore, we have shifted the plasmon resonance of nanoparticles to match that of an excitation laser wavelength, by fabrication of the silver-core gold-shell nanoparticles. By combining the laser and plasmon resonance shift towards longer wavelengths we have achieved a great reduction in background fluorescence of blood. Great enhancement of Raman signal coming solely from drugs was achieved without any prominent lines coming from the erythrocytes. We have applied chemometric processing methods, such as Principal Component Analysis (PCA), to detect the elusive differences in the Raman bands which are specific for the investigated drugs. We have achieved good classification for the samples containing particular drugs (e.g., butalbital, α-hydroxyalprazolam). Furthermore, a quantitative analysis was carried out to assess the limit of detection (LOD) using Partial Least Squares (PLS) regression method. In conclusion, our LOD values obtained for each class of drugs was competitive with the gold standard GC/MS method.

  • Features of load and wear of main propulsion devices on sea-going ships with piston combustion engines and their impact on changes in technical states of the systems
    • Jerzy Girtler
    2017 Full text Polish Maritime Research

    The paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems) of the machines have been described herein. Using examples of typical types of wear (both linear and volumetric) for the tribological systems of this sort, interpretation of states of their wear has been provided with regards to the wear levels defined as acceptable, unacceptable and catastrophic. The following hypotheses have been formulated: 1) hypothesis explaining necessity to consider the loads on the systems under operation as stochastic processes; 2) hypothesis explaining a possibility of considering the processes as stationary; and 3) hypothesis explaining why it can be assumed that a given technical state of any tribological system can be considered as dependent only on the directly preceding state and stochastically independent of the states that existed earlier. Accepting the hypotheses as true, a four-state continuous-time semi-Markov process has been proposed in the form of a model of changes in condition of a propulsion system (PS) of any ship. The model includes the most significant states affecting safety of a ship at sea, such as: s0 – PS ability state, s1 – PS disability state due to damage to the main engine (ME), s2 – PS disability state due to damage to the shaft line (SL) and s3 – PS disability state due to damage to the propeller (P). Probability of occurrence (changes) of the states has also been demonstrated.

  • FEM analysis of composite materials failure in nonlinear six field shell theory
    • Bartosz Sobczyk
    2017 Full text

    The monography deals with the problem of failure initiation in thin laminated composites. Known techniques of laminate structures modelling are briefly characterised. Eventually, shell based approach is chosen for the purpose of the description of the composite structures behaviour, as it predicts their deformation and states of stress effectively in a global sense. The nonlinear six parameter shell theory (6p theory) with asymmetric strain and stress measures is mainly used within the work and thus its main properties are described. Selected and commonly known methods of the damage onset description for laminated shells, based on the assumption of stress tensor symmetry, named as standard criteria, are studied and analyzed. These are: Tsai-Hill, Tsai-Wu, Hashin and Puck. Modifications of the aforementioned criteria meeting the requirements of the 6p theory are discussed and proposed, since no precise descriptions of the damage initiation in laminates are found in the literature when asymmetric strain and stress components are utilised. The modified criteria, allowing first ply failure (FPF) analysis of laminates, are implemented into non-commercial finite element method (FEM) code CAM. Finally, six numerical examples are solved using FEM to check if the FPF estimations resulting from the application of the standard and the modified criteria differ.

  • Fenomen przemocy w doktrynach prawnych. Tendencje legislacyjne dotyczące sprawcy i osoby doznającej przemocy
    • Przemysław Banasik
    2017

    Przemoc, aczkolwiek różnie postrzegana, stanowi przedmiot zainteresowania wielu dziedzin prawa. Pod różnymi postaciami reguluje je prawo karne, szeroko rozumiane prawo cywilne, ale także prawo pracy. Z uwagi na wieloaspektowość omawianego zjawiska niemożliwe jest przedstawienie wszystkich odsłon, a jedynie zasygnalizowanie tych obszarów, w których ono występuje i w których odgrywa szczególną rolę. Do przeprowadzenia analizy wykorzystano studia literaturowe oraz egzegezę przepisów prawnych.

  • Fermi-liquid behavior of binary intermetallic compounds Y3 M (M = Co, Ni, Rh, Pd, Ir, Pt)
    • Judyta Strychalska-Nowak
    • Bartłomiej Wiendlocha
    • Katarzyna Hołowacz
    • Paula Reczek
    • Mateusz Podgórski
    • Michał Jerzy Winiarski
    • Tomasz Klimczuk
    2017 Full text Materials Research Express

    A series of polycrystalline samples of Y3 M (M  =  Co, Ni, Rh, Pd, Ir, Pt), intermetallic binary compounds were synthesized by the arc-melting method. Powder x-ray diffraction (pXRD) confirmed the orthorhombic cementite-type crystal structure and allowed for the estimation of the lattice parameters. Physical properties were investigated by means of electrical resistivity and heat capacity measurements between 1.9 K and 300 K. All tested compounds show metallic-like behaviour with RRR values ranging from 1.3 to 8.3, and power-law $\rho \propto {{T}^{n}}$ temperature dependence of resistivity was observed, with $1.6\leqslant n\leqslant 2.2$ . No superconductivity was detected above 1.9 K. The Debye temperature, estimated from the low temperature heat capacity fit, ranged from 180 K (Y3Pt) to 222 K (Y3Co). The highest value of the Sommerfeld coefficient γ was found for Y3Pd (19.5 mJ mol−1 K−2). The pXRD pattern of Y3Rh indicated the presence of Y5Rh2, a previously unreported Pd5B2-type phase, whose unit cell parameters were refined using the LeBail method. Density functional theory calculations were performed and theoretical results revealed strong enhancement of the measured electronic specific heat, which was 30%–100% larger than computed. Quadratic temperature dependence of resistivity and enhanced electronic specific heat indicated a Fermi-liquid behavior of electrons in these materials.