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Gdańsk University of Technology

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Publications from the year 2018

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  • Raport z II etapu badań eksperymentalnych żelbetowych płyt prefabrykowanych z łącznikami balkonowymi
    • Maciej Niedostatkiewicz
    • Paweł Piotrkowski
    • Maciej Tomasz Solarczyk
    • Jarosław Kondrat
    2018

    Niniejsze opracowanie stanowi raport z II etapu badań prefabrykowanych zestawów balkonowych o wymiarach (szerokość × długość × wysokość): 2,0 m × 2,78 m × 0,186 m (w spadku do 0,17 m) składających się z żelbetowych płyt połączonych ze sobą łącznikami balkonowymi typu 1 lub typu 2.

  • Rare earth ions doped K 2 Ta 2 O 6 photocatalysts with enhanced UV–vis light activity
    • Anna Krukowska
    • Michał Jerzy Winiarski
    • Judyta Strychalska-Nowak
    • Tomasz Klimczuk
    • Wojciech Lisowski
    • Alicja Mikolajczyk
    • Henry P. Pinto
    • Tomasz Puzyn
    • Tomasz Grzyb
    • Adriana Zaleska-Medynska
    2018 APPLIED CATALYSIS B-ENVIRONMENTAL

    New rare earth-doped K2Ta2O6 photocatalysts were successfully synthesized by hydrothermal method. The effect of dopant type (Y,Yb,Ho,Pr,Er) and amount of rare earth precursor (2,4,8 and 10 mol%) on the physicochemical and photocatalytic properties of RE-K2Ta2O6 have been investigated. All as-prepared materials were characterized by UV–vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller specific surface area measurement, scanning electron microscopy with energy dispersive X-ray spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, magnetic susceptometry and photoluminescence emission spectroscopy. The photocatalytic activity under UV–vis light irradiation was estimated in phenol degradation in aqueous phase, toluene removal in gas phase and H2 generation from formic acid solution. The experimental results show that, novel RE-K2Ta2O6 exhibits greatly improved degradation efficiency under UV–vis light irradiation compared with pristine K2Ta2O6. The Er-K2Ta2O6 and Pr-K2Ta2O6, obtained by introducing of 2 mol% of RE ions during synthesis, reveal the highest photocatalytic activity among prepared samples in aqueous phase (33% of PhOH decomposition after 90 min of irradiation) and gas phase (45% of toluene removal after 60 min), respectively. Moreover, both photocatalysts present good stability after subsequent three cycles. The active species trapping test shows that OH and O2− radicals are significantly involved in phenol oxidation under UV–vis light. The amount of H2 evolution increases with addition of Er dopant. The highest H2 production is obtained for 10 mol% Er-K2Ta2O6 after 240 min of UV–vis light irradiation (15.4 μmol/min). Enhanced photoactivity performance can be attributed to incorporation of RE ions at K+ lattice site in RE-K2Ta2O6, probably leading to formation of new RE 4f states below the conduction band of K2Ta2O6 structure. To investigate the localization of RE ions in K2Ta2O6 structure, the band structure and partial density of the states have been investigated. Computer simulations were performed using plane-wave based Vienna ab-initio simulation package with the generalized gradient approximation by Perdew-Burke-Ernzerho. Moreover, inclusion of RE ions in K2Ta2O6 causes predominance of pyrochlore phase formation over perovskite.

  • RDF dataset profiling - a survey of features, methods, vocabularies and applications
    • Mohamed Ben Ellefi
    • Bellahsene Zohra
    • John G. Breslin
    • Elena Demidova
    • Stefan Dietze
    • Konstantin Todorov
    • Julian Szymański
    2018 Semantic Web

    The Web of Data, and in particular Linked Data, has seen tremendous growth over the past years. However, reuse and take-up of these rich data sources is often limited and focused on a few well-known and established RDF datasets. This can be partially attributed to the lack of reliable and up-to-date information about the characteristics of available datasets. While RDF datasets vary heavily with respect to the features related to quality, coverage, dynamics and currency, reliable information about such features is essential to enable dataset discovery in tasks such as entity linking, distributed query, search or question answering. Even though there exists a wealth of works contributing to the problem of dataset profiling in general, these works are spread across a wide range of communities. In this survey, we provide a first comprehensive survey of the RDF dataset profile features, methods, tools and vocabularies. We organize these building blocks of dataset profiling in a taxonomy and emphasize the links between the dataset profiling and feature extraction approaches and several application domains. The survey is aimed towards data practitioners, data providers and scientists, spanning a large range of communities and drawing from different fields such as dataset profiling, assessment, summarization and characterization. Ultimately, this work is intended to facilitate the reader to identify and locate the relevant features for building a dataset profile for intended applications together with the tools capable of extracting these features from the data.

  • Reactions of (Ph)tBuP-P(SiMe3)Li·3THF with [(PNP)TiCl2] and [MeNacNacTiCl2·THF]. Synthesis of first PNP titanium(IV) complex with phosphanylphosphinidene ligand [(PNP)Ti(Cl){η2-P-P(Ph)tBu}]
    • Aleksandra Ziółkowska
    • Natalia Szynkiewicz
    • Aleksandra Wiśniewska
    • Jerzy Pikies
    • Łukasz Ponikiewski
    2018 Full text DALTON TRANSACTIONS

    Lithium derivative of diphosphane (Ph)tBuP-P(SiMe3)Li (1) was isolated for the first time and investigated in reactions with β-diketiminate (MeNacnac− = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2C6H3) and PNP-pincer (PNP = N[2-PiPr2-4-methylphenyl]2) Ti(III) complexes. The β-diketiminate titanium(III) complex containing phosphanylphosphido ligand [MeNacNacTi(Cl){η2-P(SiMe3)-P(Ph)tBu}] (2) was prepared in reaction of [MeNacNacTiCl2·THF] with (Ph)tBuP-P(SiMe3)Li in toluene solution with good yield and purity. Respective titanium(IV) complex involving phosphanylphosphinidene ligand [MeNacNacTi(Cl){η2-P-P(Ph)tBu}] (3) was synthesized by oxidation of complex (2) with [iBu3PAgCl]4. Interestingly, an analogus PNP titanium(IV) complex [(PNP)Ti(Cl){ɳ2-P-P(Ph)tBu}] (4) was obtained in the reaction of [(PNP)TiCl2] with (Ph)tBuP-P(SiMe3)Li in toluene solution and 1 : 1 molar ratio instead of the expected titanium(III) complex with phosphanylphosphido ligand. Solid-state structures of (Ph)tBuP-P(SiMe3)Li·3THF (1), [MeNacNacTi(Cl){η2-P(SiMe3)-P(Ph)tBu}] (2), [MeNacNacTi(Cl){η2-P-P(Ph)tBu}] (3) and [(PNP)Ti(Cl){ɳ2-P-P(Ph)tBu}] (4) determined by single-crystal X-ray diffraction reveald that in all obtained complexes both, the phosphanylphosphinidene (Ph)tBuP-P and phosphanylphosphido (Ph)tBuP-P(SiMe3) ligands are bidently coordinated to the metal center.

  • Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
    • Krzysztof Formela
    • Łukasz Zedler
    • Aleksander Hejna
    • Agnieszka Tercjak
    2018 Full text Express Polymer Letters

    Reactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application for processing of bio-based polymer blends and composites is a relatively new direction of scientific research. This work presents a literature review on recent advances in the processing of bio-based polymer blends and composites via reactive extrusion. We described compatibilization mechanisms for different types of biodegradable polymeric materials based on: (i) aliphatic polyesters, (ii) aliphatic polyesters/starch and (iii) aliphatic polyester/natural rubber systems. A special attention was focused on conventional and dynamic cross-linking of bio-based polymer blends and composites as an effective way to prepare new materials with unique properties e.g. biodegradable thermoplastic elastomers or shape-memory materials. Advantages and limitations affecting future trends in development of biodegradable polymer blends and composites reactive extrusion are also discussed.

  • REALIZACJA ELEMENTÓW SKŁADOWYCH ŁĄCZA RADIOWEGO Z UŻYCIEM URZĄDZEŃ RADIA PROGRAMOWALNEGO TYPU USRP
    • Damian Gierczak
    • Jacek Stefański
    2018

    Przez ostatnią dekadę projektowanie systemów radiowych zaczęło w coraz większym stopniu polegać na cyfrowym przetwarzaniu sygnałów. Możliwość i moc obliczeniowa procesorów ogólnego przeznaczenia GPP (General Purpose Processor), procesorów sygnałowych DSP (Digital Signal Processor) oraz układów programowalnych FPGA (Field Programmable Gate Array) znacząco wzrosła zgodnie z prawem Moor’a. Naturalnym następstwem tego trendu było większe zastosowanie przetwarzania sygnałów realizowanego programowo. Systemy radiowe zyskały większą zdolność adaptacji do konkretnych rozwiązań dzięki zastosowaniu oprogramowania, a charakterystyka systemu może zostać zmieniona poprzez zmianę oprogramowania. Jednak pomimo zwiększonego zastosowania oprogramowania do realizacji funkcjonalności elementów składowych łącza radiowego większość producentów rozwijała swoje własne rozwiązania co do architektury i implementacji. Z tego względu architektura, mechanizmy kontroli i zarządzania mogą być zróżnicowane w systemach radiowych i niekompatybilne między sobą. Często urządzenia projektowane były jako rozwiązania dedykowane do konkretnych zadań i współpracowały jedynie z oprogramowaniem producenta co uniemożliwiało współpracę różnych służb, czy jednostek wojskowych stosujących bliźniacze systemy między sobą. W związku z tym powstały standardy i rekomendacje mające na celu ujednolicenie rozwiązań i zapewnienie uniwersalności urządzeń, oraz oprogramowania [1]. W artykule przedstawiona zostanie charakterystyka radia programowalnego wraz z zasadami ustalonymi w celu zapewniania uniwersalności i możliwości współpracy urządzeń i systemów różnych producentów. Następnie opisany zostanie sposób realizacji elementów składowych łącza radiowego przy użyciu urządzenia radia programowalnego typu USRP.

  • REALIZACJA NADAJNIKA I ODBIORNIKA OFDM W TECHNOLOGII RADIA PROGRAMOWALNEGO
    • Andrzej Marczak
    2018

    Metoda wielodostępu OFDM, jest stosowana obecnie w wielu nowoczesnych cywilnych i wojskowych standardach łączności radiowej. Technologia radia programowalnego (ang. Software Defined Radio) umożliwia realizacje urządzeń pracujących z tą metodą wielodostępu. W referacie zaprezentowano przykłady dwóch środowisk oprogramowania służących do realizacji oprogramowania w technologii SDR. Przedstawiono również przykłady platform sprzętowych SDR. Zaprezentowano również przykładową aplikację nadajnika i odbiornika OFDM uruchomioną na platformie sprzętowej SDR.

  • Real-Time Facial Features Detection from Low Resolution Thermal Images with Deep Classification Models
    • Alicja Kwaśniewska
    • Jacek Rumiński
    • Krzysztof Czuszyński
    • Maciej Szankin
    2018 Journal of Medical Imaging and Health Informatics

    Deep networks have already shown a spectacular success for object classification and detection for various applications from everyday use cases to advanced medical problems. The main advantage of the classification models over the detection models is less time and effort needed for dataset preparation, because classification networks do not require bounding box annotations, but labels at the image level only. Yet, after passing the image through a stack of convolutions followed by stride and pooling operations the full image is reduced into a single vector of class probabilities and the spatial arrangement of pixels is completely lost. Our proposed approach shows how to localize objects by restoring the spatial information about features distribution from the classification network. The presented modifications of architecture are limited to the inference phase only. As a result, we are able to combine the simplicity and short time required for dataset preparation with the results similar to the output from the detection model. Additionally, we showcased that it is possible to repurpose the existing network, originally trained on RGB images, to a novel task of facial features detection from low resolution thermal images, while preserving the high precision (>99%). The proposed facial features detection system can be potentially combined with wearable devices that will collect data and send it to the server for more computationally expensive analysis, e.g., calculation of the respiratory rate form the detected nostril area. Real time performance and small resource utilization proved that the presented approach can be used to serve multiple patients without any impact on the latency, e.g., as a centralized monitoring station for the home healthcare. The combination of wearable devices with machine learning algorithms run on the remote and more powerful platforms could revolutionize the practice of medicine by delivering healthcare to patients anywhere in the world.

  • Recent advances in assessing xenobiotics migrating from packaging material – A review
    • Natalia Jatkowska
    • Błażej Kudłak
    • Jacek Namieśnik
    2018 Full text ANALYTICA CHIMICA ACTA

    Migration of potentially toxic xenobiotics and their transformation products from packaging materials needs continuous monitoring efforts. This task requires utilizing both instrumental and biological methods as more and more novel materials reach market every year to serve consumers and reduce production costs. Unfortunately, these materials very often sneak past our legal regulations on their composition and emission of contaminants due to contact with the materials or products stored. For these reasons, more and more novel, holistic and multi-tier approaches must be elaborated to uncompromisingly assure safety of these materials to living creatures. In the work presented, a review of methods enabling performing studies on extraction, leaching, qualitative and quantitative determination of xenobiotics and their combined effect on certain biological endpoints is given. Additionally, a basic approach guiding end-users and scientists to elaborate such studies is presented in the form of a basic scheme, and advantages and disadvantages of these methods are summarized.

  • Recent advances in rapid multiobjective optimization of expensive simulation models in microwave and antenna engineering by Pareto front exploration
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2018 Full text INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING

    Practical engineering design problems are inherently multiobjective, that is, require simultaneous control of several (and often conflicting) criteria. In many situations, genuine multiobjective optimization is required to acquire comprehensive information about the system of interest. The most popular solution techniques are populationbased metaheuristics, however, they are not practical for handling expensive electromagnetic (EM)-simulation models in microwave and antenna engineering. A workaround is to use auxiliary response surface approximation surrogates but it is challenging for higher-dimensional problems. Recently, a deterministic approach has been proposed for expedited multiobjective design optimization of expensive models in computational EMs. The method relies on variable-fidelity EM simulations, tracking the Pareto front geometry, as well as response correction. The algorithm sequentially generates Pareto-optimal designs using a series of constrained singleobjective optimizations. The previously obtained design is used as a starting point for the next iteration. In this work, we review this technique and its modification based on space mapping surrogates. We also propose new variations exploiting adjoint sensitivities, as well as response features, which can be attractive depending on availability of derivatives or the characteristics of the system responses that need to be handled. We also discuss several case studies involving various antenna and microwave components.

  • Recovery of silver metallization from damaged silicon cells
    • Anna Kuczyńska-Łażewska
    • Ewa Klugmann-Radziemska
    • Zuzanna Sobczak
    • Tomasz Klimczuk
    2018 Full text SOLAR ENERGY MATERIALS AND SOLAR CELLS

    Metallization is one of the key process steps to fabricate solar cells with high performance in a cost-effective way. Majority of photovoltaic solar cell manufacturing uses thick film screen print metallization with Ag containing paste to produce solar cells. The average lifetime of PV modules can be expected to be more than 25 years. The disposal of PV systems will become a problem in view of the continually increasing production of PV modules. These can be recycled for about the same cost as their disposal. The proposed method of acidic and basic etching of contacts, presented in this article can be successfully applied to broken solar cells from the landfill without a specialist analysis procedure. The amount of silver that can be recovered from the etching solution is up to 1.6 kg/t of broken solar cells. The step-by-step procedure improves efficiency of silver recovery. The best and easiest method for general verification of the silver etching rate is classic titration with suitable concentrations of titrant solution.

  • Recycled Polyurethane as a Second Phase in Thermoset Blends and Its Effect on Thermal Degradation Kinetics Studies
    • Arunima Reghunadhan
    • Michał Strankowski
    • Janusz Datta
    • Nandakumar Kalarikkal
    • Sabu Thomas
    2018 MACROMOLECULAR SYMPOSIA

    A new approach is introduced in the modification of thermosetting polymer by using different amount of polyurethane of waste origin. The post consumer polyurethane foam coatings are degraded using glycolysis process and the recycled product is further converted into new polyurethane. The blending of recycled polyurethane with epoxy exhibits transparency and produces nanostructures. The effective interaction between two polymers is confirmed with dynamic mechanical analysis at 10 Hz. Selected relaxations are also noticed by the inclusion of the flexible PU chains at low temperature regions. The glass transition temperature shows a shift in value from neat epoxy indicating effective miscibility of the flexible domains. The initial degradation temperatures of the blends are increased by the polyurethane inclusion, which is confirmed by thermogravimetric analysis. The increase is more than 25 °C for the 20 phr inclusion. The thermal degradation kinetics is correlated with different theoretical equations like Cord‐Redfern, Horowitz‐Metzger, and Broido.

  • Redesign of the Research Platform for Monitoring, Control and Security of Critical Infrastructure Systems
    • Tomasz Zubowicz
    • Krzysztof Armiński
    • Dawid Obremski
    • Jakub Pieńczewski
    2018 Full text

    Critical Infrastructure Systems (CISs) play a key role in modern societies. Their sustainable operation depends heavily on the performance of dedicated structures and algorithms targeting monitoring, control and security aspects. In previous work a Research Platform (RP) for the design and simulation of such systems was presented. This works updates the information on the RP through the description of major hardware and software updates made. An example illustrating how this is to serve to include undergraduate students into research work is included.

  • Reduced Graphene Oxide Joins Graphene Oxide To Teach Undergraduate Students Core Chemistry and Nanotechnology Concepts
    • Izabela Kondratowicz
    • Małgorzata Nadolska
    • Kamila Sadowska
    2018 JOURNAL OF CHEMICAL EDUCATION

    Novel carbon nanomaterials such as reduced graphene oxide (rGO) and graphene oxide (GO) can be easily incorporated into the undergraduate curriculum to discuss basic chemistry and nanotechnology concepts. This paper describes a laboratory experiment designed to study the differences between GO and rGO regarding their physico-chemical properties (e.g. color, hydrophobicity, type of functional groups, electrical conductivity etc.). In this course, students carry out the chemical reduction of GO using ascorbic acid, a mild and environmentally friendly reducing agent. The differences between GO and rGO can be spotted by naked eye and can be further evaluated by spectroscopic methods, as FTIR and UV-vis spectroscopy, and X-ray diffraction. Simple and applicable in all laboratories method was proposed to reveal the different electrical properties of GO and rGO. Moreover, the proposed laboratory experiment is an ideal pretext to discuss the definition of graphene in the context of the overuse of this term in the literature.

  • Reduced-cost constrained miniaturization of wideband antennas using improved trust-region gradient search with repair step
    • Adrian Bekasiewicz
    • Sławomir Kozieł
    • Qingsha Cheng
    2018 IEEE Antennas and Wireless Propagation Letters

    In the letter, an improved algorithm for electromagnetic (EM)-driven size reduction of wideband antennas is proposed. Our methodology utilizes variable-fidelity EM simulation models, auxiliary polynomial regression surrogates, as well as multi-point response correction. The constraint handling is implicit, using penalty functions. The core optimization algorithm is a trust-region gradient search with a repair step added in order to facilitate exploration of the feasible region boundary. The latter results in considerable reduction of the computational cost of the optimization process. The proposed methodology is demonstrated using two wideband monopole antennas and compared to both direct optimization of the high-fidelity model and the surrogate-assisted framework without the aforementioned repair step. The results indicate superiority of the presented approach. Experimental validation of the fabricated prototypes of the optimized antennas is also provided.

  • Reduced-cost surrogate modeling of input characteristics and design optimization of dual-band antennas using response features
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2018 Full text INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING

    In this article, a procedure for low-cost surrogate modeling of input characteristics of dual-band antennas has been discussed. The number of training data required for construction of an accurate model has been reduced by representing the antenna reflection response to the level of suitably defined feature points. The points are allocated to capture the critical features of the reflection characteristic, such as the frequencies and the levels of the resonances, and supplemented by the additions (infill) points, which is necessary to provide sufficient data that allows restoring the entire response through interpolation. Because the coordinates of the feature points exhibit less nonlinear behavior (as a function of antenna geometry parameters) compared to S-parameters as a function of frequency, surrogate model construction can be realized with a smaller number of data points. The presented modeling approach is demonstrated using an example of a planar dipole antenna. Also, the feature-based method is favorably compared to direct modeling of reflection characteristics using kriging. The relevance of the technique is further verified by its application for design optimization.

  • Reduction of Computational Complexity in Simulations of the Flow Process in Transmission Pipelines
    • Zdzisław Kowalczuk
    • Marek Sylwester Tatara
    • Tomasz Stefański
    2018 Full text Advances in Intelligent Systems and Computing

    The paper addresses the problem of computational efficiency of the pipe-flow model used in leak detection and identification systems. Analysis of the model brings attention to its specific structure, where all matrices are sparse. With certain rearrangements, the model can be reduced to a set of equations with tridiagonal matrices. Such equations can be solved using the Thomas algorithm. This method provides almost the same values of the state vector and maintains stability for the same discretization grid, while the computational overhead is thus significantly reduced.

  • Reduction of measurement data before Digital Terrain Model generation vs. DTM generalisation
    • Wioleta Błaszczak-bąk
    • Marian Poniewiera
    • Anna Sobieraj-Żłobińska
    • Michał Kowalik
    2018 SURVEY REVIEW

    Modern data acquisition technologies provide large datasets that are not always necessary in its entirety to properly accomplish the goal of the study. In addition, such datasets are often cumbersome for rational processing, and their processing is time and labour consuming. Therefore, methods that enable to reduce the size of the measurement dataset, such as the generalization of the Digital Terrain Model (DTM) or the reduction method at the initial processing of measurement data, are often used. Such methods of reduction can include the Optimum Dataset method (OptD). The paper presents two approaches of decrease the LiDAR (Light Detection and Ranging) dataset. The first approach is based on the generalization of DTM in AutoCADCivil 3D 2018, the second is based on the OptD method. Obtained reduced datasets were used to create the isoline maps that depict overflow land in open-pit mining. The results of the study have allowed to formulate conclusions which show that the reduction must be well-thought and that the degree of reduction must be set in a way, that it allows to maintain the characteristics of the terrain.

  • REDUNDANCY AS A WAY INCREASING RELIABILITY OF SHIP POWER PLANTS
    • Wiesław Tarełko
    2018 Full text New Trends in Production Engineering

    One of key ways of assuring a high level of reliability of a ship power plant is to design redundancy of its structural elements, for example redundancy of prime drivers, drivelines etc. This paper deals with issues related to the redundancy as a way increasing dependability of the ship power and propulsion systems. Especially, fundamental characteristics of dependability, major design strategies influencing the reliability, and types of redundancies related to ship power and propulsion systems are presented.

  • Redundant information encoding in QED during decoherence
    • Jan Tuziemski
    • Piotr Witas
    • Jarosław Korbicz
    2018 Full text PHYSICAL REVIEW A

    Broadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.-Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many real-life situations, has not been analyzed yet. We present such an analysis for a nonrelativistic, pointlike charge and thermal radiation. In the dipole approximation, we solve the dynamics and show that there is a regime where, despite the noise, the observed field carries away almost perfect and hugely redundant information about the charge momentum. We analyze a partial charge-field state and show that it approaches a so-called spectrum broadcast structure.