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Publications Repository
Gdańsk University of Technology

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Publications from the year 2016

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  • Prediction of ringing frequencies in DC-DC boost converter
    • Piotr Musznicki
    • Marcin Ruciński
    • Marek Turzyński
    • Stanisław Abramik
    2016

    In the paper ringing phenomena in a DC-DC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.

  • Predykcja częstotliwości oscylacji komutacyjnych w wielotransformatorowej przetwornicy typu Flyback
    • Marcin Ruciński
    • Stanisław Abramik
    • Piotr Musznicki
    • Maciej Kolincio
    2016 Full text Przegląd Elektrotechniczny

    W artykule przedstawiono koncepcję analitycznej predykcji częstotliwości zaburzeń elektromagnetycznych generowanych w przekształtnikach energoelektronicznych. Analizę zaburzeń przeprowadzono na przykładzie wielotransformatorowej przetwornicy w topologii Flyback. Wyniki obliczeń zostały zweryfikowane z pomiarami laboratoryjnymi prototypu przetwornicy.

  • Pre-feasibility study for treatment wetland application for wastewater treatment in dispersed development
    • Magdalena Gajewska
    • Katarzyna Kołecka
    • Hanna Obarska-Pempkowiak
    • Ewa Wojciechowska
    • Arkadiusz Ostojski
    • Aleksandra Bejnarowicz
    2016 Full text Journal of Ecological Engineering

    The aim of the paper is to present the conducted analyses of pre-feasibility study of different approaches for wastewater management in a settlement of 180 persons. In the assessment both technical and economic aspects were analyzed. The costs were calculated for three different and, at the same time, most popular as well as possible technical solutions like: (i) construction of local wastewater treatment plant with gravitational and pressurized networks, (ii) construction of single family wastewater treatment plants, (iii) construction of sealed septic tanks. Carried out analyses of investment and maintenance costs revealed that at the stage of construction the most expensive is local sewer network with treatment plant, while the construction of a single family treatment plant has similar cost regardless of the technology used. When the long term operation and investment cost are accounted the most economical reasonable solution is the application of wetland treatment for household wastewater treatment.

  • Preliminary experimental research on stability of truss' joint with positive eccentricity
    • Małgorzata Gordziej-Zagórowska
    • Elżbieta Urbańska-Galewska
    • Łukasz Pyrzowski
    • Patryk Deniziak
    • Agnieszka Łukowicz
    2016

    Recently, a very large interest in lightweight steel structures made from cold-formed sections has been noticeable. In the design practice, a large emphasis is put on rational shaping of both the thin-walled elements and constructions designed on them. The aim of this paper is to present the methodology for preparation of experimental research that model the behaviour of members in trusses made of cold-formed sections with positive eccentricity in the joint and presentation of these research results. The research problem concerning the real load-carrying capacity of the compressed and bent chord of the lattice girder has been presented in the paper. The laboratory stand for experimental research is described and methodology of the tests presented. Results of the tests which gave the basis for the verification of the research model’s and stand’s project are presented.

  • Preparation and Characterization of Nanomaterial Consisting of Silica Aerogel & Carbon Tested as an Electrode in Non-Aqueous Media Containing Lithium Salt.
    • Anna Lisowska-Oleksiak
    • Beata Wicikowska
    • Andrzej Nowak
    • Zbigniew Olejniczak
    • Czesław Kapusta
    2016 Full text International Journal of Electrochemical Science

    Silica aerogel (SiO2ag) was combined with carbonaceous material in the pyrolysis process of hydrocarbons. The obtained nanocomposite SiO2ag/C was amorphous, partially preserving the porous structure of SiO2ag. The specific surface area changes from 445.6 m2/g for pure SiO2ag to 205.52 m2/g SiO2ag/C. The 29Si MAS-NMR shows a three-dimensional matrix with silicon atoms connected to other silicon atoms by four and three oxygen bridges. The Raman spectrum reveals the state of carbonaceous material, with typical D and G peaks, derived from hydrocarbon pyrolysis. SiO2ag/C was tested as an electrode in contact with LiPF6 in the EC/DMC electrolyte. Electrochemical measurements showed the presence of complex redox couple activities of SiO2ag/C. XPS was employed to identify products obtained under polarization of SiO2ag/C. Silica reduction proceeds with Li2O, Li2Si2O3, Li2Si2O5,Li4SiO4 and LixSi formation. The charge capacity after 30 cycles is equal to 550 mAh/g.

  • Preparation and characterization of porous scaffolds from chitosan-collagen-gelatin composite
    • Robert Tylingo
    • Grzegorz Gorczyca
    • Szymon Mania
    • Piotr Szweda
    • Sławomir Milewski
    2016 Full text REACTIVE & FUNCTIONAL POLYMERS

    Novel porous scaffolds composed of chitosan, collagen and gelatin were prepared and characterized. For preparing scaffolds gelatin and collagen isolated from fish skins with various physicochemical properties were used. In order to reduce preparation solubility glutaraldehyde in the amount of 1%, w/w relative to the total biopolymers weight in solution was used. All obtained biomaterials showed a homogeneous porosity. Protein polymer type determined the rheology and mechanical properties of obtaining preparations. The use of protein polymers decreased swelling capacity of materials approximately 30% compared to the materials obtained from chitosan. Materials containing gelatin showed the highest solubility (approx. 30%). Scaffolds obtained in 100% of chitosan proved to be harder than collagen materials an average of 30% and less flexible more than twice. In relation to the gelatin materials were characterized by smaller values of both measured parameters on average 40% and 30% respectively. Materials containing protein polymers showed good antioxidant properties.

  • Preparation, characterization and photocatalytic activity of TiO2 microspheres decorated by bimetallic nanoparticles
    • Ewelina Grabowska
    • Martyna Marchelek
    • Tomasz Klimczuk
    • Grzegorz Trykowski
    • Adriana Zaleska-Medynska
    2016 JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL

    Composite photocatalysts that consist of TiO2and noble metal nanostructures have been considered tobe the promising and pivotal material for accessible enhancement of the efficiency in the photocatalyticprocess carried out in the aqueous and gas phases. In this work we fabricated porous TiO2microspheresthrough a hydrothermal process followed by photochemical reduction of noble metal nanoparticles atthe TiO2surface. The morphology and structure of M-TiO2spheres (M = Ag, Au, Pt and Pd) were studiedwith the use of various techniques, including transmission electron microscopy (TEM), X-ray powderdiffraction analysis (XRD), photoluminescence (PL) and UV–vis diffuse-reflectance spectroscopy (DRS).The effect of metal amount (from 0.1 to 1 wt.%.) on the photocatalytic activity during toluene degradationin gas phase and phenol degradation in aqueous phase was investigated. Additionally, the photocatalyticactivity of the M-TiO2samples was evaluated by measuring the formation rate of photo-induced hydroxylradicals (•OH) under UV–vis light irradiation using coumarin as a probe. The obtained results indicatedthat toluene could be mostly removed from the air over TiO2microspheres modified with Ag, Au, Pt, andPd nanoparticles. UV-mediated photoreactivity was almost similar for all samples obtained by loadingmetals from solutions consisting of 0.1 and 1 wt.% of metal precursors. Under visible light, except for Au, ingas phase toluene oxidation, the optimized loading of the metals was 0.1 wt.-% (photoreactivity changedin order: Ag-TiO2≈ Pd-TiO2> Pt-TiO2» Au-TiO2). In case of phenol degradation in the aqueous phase, inthe presence of UV irradiation the highest amount of metal (1.5 wt.%) was profitable, while under the Vislight reaction the medium amount of metal (0.5 wt.%) was beneficial. Additionally, it was noticed thatphenol was degraded not only via oxidation by•OH radicals but probably also in direct reaction withthe photogenerated carriers (e−/h+), particulary in the presence of TiO2spheres loaded with Au and Agnanoparticles.

  • President and Manager of the court versus networking in justice system - "Extending of Delimitation"
    • Przemysław Banasik
    • Sylwia Morawska
    • Joanna Kuczewska
    2016

    Current knowledge and empirical studies concering the networks collaboration in public sector, the role of decision-making centre in the building of network structure, strategy formulation and evaluation is fragmentary.

  • Pressure drop of HFE7000 and HFE7100 during flow condensation in minichannels
    • Dariusz Mikielewicz
    • Jan Wajs
    • Rafał Andrzejczyk
    • Michał Klugmann
    2016 INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID

    Attention is focused on the issues of flow resistance and pressure drop of perspective refrigeration fluids during condensation in the two-phase flow in minichannels. The case of the flow through a cylindrical single channel of 2.3 mm inner diameter was carefully analyzed. Pressure drop tests have been performed in diabatic flow conditions. The effect of heat flux, mass flux, vapour quality and saturation temperature on the two-phase pressure drop have been scrutinised. In the course of investigations, the new fluids, namely HFE 7100 and HFE 7000, have been tested. Calibration of the measurement system for the case of single phase flow and comparison of the results with the Blasius friction correlation show the accuracy of ±15%. Additionally, the data were compared with some well established correlations for two-phase flow exhibiting that the correlation due to Fronk and Garimella (2010) and the in-house model are found in best agreement with the experimental data.

  • Principles and applications of Ligation Mediated PCR methods for DNA-based typing of microbial organisms
    • Beata Krawczyk
    • Józef Kur
    • Karolina Stojowska-Swędrzyńska
    • Marta Śpibida
    2016 Full text Acta Biochimica Polonica

    A significant number of DNA-based techniques has been introduced into the field of microorganisms’ characterization and taxonomy. These genomic fingerprinting methods were developed to detect DNA sequence polymorphisms by using general principles, such as restriction endonuclease analysis, molecular hybridization, and PCR amplification. In recent years, some alternative techniques based on ligation of oligonucleotide adapters before DNA amplification by PCR, known as Ligation-Mediated PCR methods (LM PCR), have been successfully applied for the typing of microorganisms below the species level. These molecular methods include: Amplified Fragment Length Polymorphism (AFLP), Amplification of DNA fragments Surrounding Rare Restriction Sites (ADSRRS), PCR Melting Profiles (PCR MP), Ligation Mediated PCR/Shifter (LM PCR/Shifter), Infrequent-Restriction-Site Amplification (IRS PCR), double digestion Ligation Mediated Suppression PCR (ddLMS PCR). These techniques are now applied more and more often because they involve less time, are comparably inexpensive, and require only standard lab equipment. Here, we present a general review of this group of methods showing their possibilities and limitations. We also identify questions and propose solutions which may be helpful in choosing a particular LM PCR method for the achievement of the required goal.

  • Principles and Developments of Solid-Phase Microextraction
    • Adam Kloskowski
    • Łukasz Marcinkowski
    • Francisco Pena-Pereira
    • Jacek Namieśnik
    2016

    Sample preparation has been commonly considered a critical step of the analytical process. In this sense, remarkable efforts have been made to develop efficient sample preparation techniques which could overcome the limitations of conventional approaches. Since its inception in the early 1990’s, solid-phase microextraction (SPME) has become a widespread miniaturized sample preparation technique for extraction and preconcentration of target analytes from a large variety of matrices. Interestingly, sampling, extraction, enrichment and sample introduction can be integrated into a single step in SPME. This book chapter focuses on the basic principles and current state of the art of SPME. Specifically, both thermodynamic and kinetic aspects of the SPME technique are discussed in detail. In addition, those experimental variables that show a paramount role in the extraction process, and should therefore be optimized and controlled for optimal performance, are considered. Valuable contributions that enabled the development of this solventless technique and current challenges are identified. Other related SPME devices, such as internally cooled SPME, in-tube SPME and membrane SPME, are also described.

  • Problem modelowania połączeń pomiędzy obiektami zabytkowymi, a elementami nowoprojektowanymi
    • Monika Zielińska
    • Karol Grębowski
    2016 Przegląd Budowlany

    W artykule przedstawiono badania i symulacje numeryczne dotyczące modelowania połączeń pomiędzy obiektami zabytkowymi, a elementami nowoprojektowanymi. Zakres prac obejmuje projekt koncepcyjny zewnętrznej klatki schodowej wraz z tarasem obserwacyjnym połączonej z zabytkową wieżą ciśnień, która znajduje się na terenie Politechniki Gdańskiej, badania doświadczalne oraz symulacje numeryczne różnego rodzaju podparcia elementów klatki schodowej na zabytkową wieżę. Wyniki badań i symulacji pozwolą na zobrazowanie wpływu pracy nowoprojektowanych konstrukcji współpracujących z obiektami dziedzictwa kulturowego.

  • Problem zatruwania siarką w tlenkowych ogniwach paliwowych zasilanych biogazem
    • Agata Warych
    • Beata Bochentyn
    2016

    Praca ta zwiera podsumowanie różnych mechanizmów odpowiedzialnych za spadek wydajności i degradację SOFC zasilanych paliwami węglowodorowymi zanieczyszczonymi związkami siarki. Wymieniono również różne sposoby i strategie stosowane w celu umożliwienia zastosowania biogazu jako paliwa dla tych ogniw, poprzez m.in. modyfikacje materiałów anodowych czy zoptymalizowanie warunków pracy ogniwa.

  • Problematyka konstrukcyjna zabytkowego obiektu przywracanego do użytkowania na przykładzie kamienicy przy ul. Staromiejskiej w Olsztynie = Structural aspects in restoring historical buildings for re-use: the case of a tenement building on Staromiejska Street in Olsztyn
    • Monika Zielińska
    • Joanna Misiewicz
    2016 Full text Wiadomości Konserwatorskie

    The paper discusses the issue of introducing structural changes into a historical building referring to the example of conservation work carried out in the tenement house at 6 Staromiejska in Olsztyn. Building work involved a general renovation. The paper reviews actions carried out in the restoration work, including strengthening and deepening of the foundations, introducing a post and beam system, and putting into placea reinforced concrete staircase. Conservation work strengthened and stabilized the building structure, while at the same time preserving the historical character of its individual elements. The strengthening and deepening of the foundations secured the building structure against settlement, leaving in place the original stone elements.The introduction of a post and beam system assured the structural stiffness of the building, while maintaining the brick walls as intact as possible. The reinforced concrete staircase was placed in the south-eastern part of the building and helped to stabilize structurally the building, while meeting the fire safety standards for public utility buildings. Preservation of two flightsof the original wooden stairs ensured that the building’s historical character was preserved.The paper seeks to demonstrate that it is possible to achieve a compromise between conservationand structural considerations. Proper work planning, in consultation with the authorities overseeing preservation and conservation work provides a route to protecting cultural heritage for future generations.

  • Problematyka modelowania zależności prędkość – gęstość – natężenie w warunkach ruchu miejskiego
    • Paulina Matusz
    • Grzegorz Rudecki
    • Jacek Oskarbski
    • Kazimierz Jamroz
    2016 Full text Transport Miejski i Regionalny

    Pierwszy model charakteryzujący zależność prędkość – gęstość – natężenie powstał ponad 80 lat temu. Od tego czasu naukowcy z całego świata pracowali nad opracowaniem własnych modeli ruchu drogowego, które kompleksowo opisywać będą fundamentalny wykres. Prace nad doborem odpowiednich parametrów, niezbędnych do stworzenia modelu, dokonywano głównie na drogach szybkiego ruchu. Problem poruszony w niniejszym referacie odnosi się do niedostatecznej ilości przeprowadzonych badań nad zagadnieniem zależności prędkość – gęstość – natężenie w warunkach miejskich w Polsce. Celem artykułu jest ocenienie możliwości implementacji istniejących modeli ruchu w sieci ulicznej na przykładzie Trójmiasta, wraz z opracowaniem autorskiej metodologii badań, adekwatnej do posiadanych narzędzi. Podjęto próbę opracowania modeli dla ruchu przerywanego w celu lepszego poznania wpływu sygnalizacji świetnej i innych utrudnień w warunkach miejskich na kształt fundamentalnego wykresu.

  • PROBLEMS OF COLLISIONS BETWEEN ADJACENT STEEL STRUCTURES UNDER EARTHQUAKE EXCITATION
    • Barbara Sołtysik
    • Robert Jankowski
    2016 Full text Civil and Environmental Engineering Reports

    Nowadays, the high level of urbanization forces the engineers to design closely-separated structures and to take into account many factors influencing their response, including collisions between them due to insufficient separation distance during moderate to strong ground motions. Recent observations as well as experimental and numerical investigations have confirmed that interactions between structures may lead to significant damage of structural elements and even to its total collapse. The aim of this paper is to investigate the influence of collisions between three insufficiently separated models of steel structures on structural response under earthquake excitation. The experimental tests as well as numerical analyses have been conducted in the study.

  • Problems of Connecting Wind Farms to the Power System with HV Cables
    • Jacek Klucznik
    2016 Full text Acta Energetica

    This paper presents problems caused by connecting wind farms to a power system with high voltage cables. The author highlights possible problems with reactive power compensation, depending on the arrangement of the shunt reactor connection and settings of control systems for reactive power and voltage of the wind farm. The paper also discusses issues of increasing active power losses caused by a shunt reactor installation.

  • PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
    • Roman Liberacki
    2016 Full text Journal of Polish CIMEEAC

    The article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate the results? Can we use a linear relationship between the weight loss of the test piece and the time? At the end of the article, the initial conception of the laboratory stand is proposed.

  • Problems of Selecting Protection for Shunt Reactors Working in Extra-High Voltage Grids
    • Zbigniew Lubośny
    • Jacek Klucznik
    • Krzysztof Dobrzyński
    2016 Full text Acta Energetica

    This paper presents difficulties encountered when designing protection devices for shunt reactors connected directly to extra-high voltage grids. Using the example of the 400 kV Ełk Bis substation, it has been demonstrated that protection of a shunt reactor based on equipment using measurements of electrical signals from voltage and current transformers has its limitations and, in some cases, may be insufficient.

  • Problemy ankietyzacji przeprowadzanej wśród studentów i ich wpływ na jakość kształcenia na Politechnice Gdańskiej
    • Barbara Wikieł
    2016 Dzień Jakości PG

    Badania ankietowe przeprowadzane wśród studentów, stanowiących najliczniejszą grupę beneficjentów systemu szkolnictwa wyższego, są istotnym elementem podnoszenia jakości kształcenia na każdej uczelni. Funkcjonujący na Politechnice Gdańskiej system badań ankietowych uwzględnia dwa rodzaje ankiet wypełnianych przez studentów: ankietę oceny nauczyciela akademickiego, ankietę oceny modułu/przedmiotu. Zebrane i opracowane wyniki prowadzonych badań ankietowych, będące zarazem - w przypadku pierwszej ankiety - jednym z elementów systemu oceny pracy nauczycieli akademickich uczelni, stanowią podstawę do wdrażania rozwiązań sprzyjających poprawie jakości kształcenia poprzez doskonalenie programów kształcenia. Niemniej jednak monitorowanie procesu dydaktycznego i jego ewaluacja w oparciu o wymienione wyżej badania ankietowe napotyka na szereg różnorodnych problemów. W publikacji omówione zostały wybrane spośród tych problemów.