Publications Repository - Gdańsk University of Technology

Page settings

polski
Publications Repository
Gdańsk University of Technology

Show publications from the year

Publications from the year 2018

Show all
  • Prace rozwojowe nad pierwszą polską ładowarką teleskopową
    • Paweł Załuski
    • Piotr Patrosz
    • Marta Zaleska
    2018 Full text Napędy i Sterowanie

    W artykule dokonano przeglądu prac wykonanych przez członków Zespołu Hydrauliki i Pneumatyki Wydziału Mechanicznego Politechniki Gdańskiej w ramach programu „Bon na innowacje” dla firmy „Hydro-Metal Adam Gordziejczyk”. Obiektem prac była ładowarka teleskopowa z napędem hydraulicznym o udźwigu 1,5 T. Pierwsza część prac polegała na obliczeniach MES i poprawie sztywności konstrukcji ramy i wysięg­nika. Druga część prac polegała na zaprojektowaniu dwóch wersji układu hydraulicznego – ekonomicznej i zaawansowanej. Prace nad układem hydraulicznym podzielono na prace nad układem zasilania narzędzi, układem skrętu, układem chłodzenia i układem jazdy.

  • Praktyczne efekty analizy konstrukcji żelbetowych i sprężonych z uwzględnieniem zarysowania betonu
    • Krzysztof Żółtowski
    2018

    W artykule zawarto wybrane przykłady problemów strukturalnych związanych z modelowaniem zarysowania betonu zbrojonego. Zaprezentowano przykłady i studia przypadku. Model zarysowanego betonu pozwala przewidzieć naprężenia charakterystyczne w zbrojeniu i betonie. Pozwala również ocenić wielkość zarysowania oraz wpływ na redystrybucję sił wewnętrznych w zarysowanej konstrukcji. Taki rodzaj analizy jest dostępny w wysokiej jakości oprogramowaniu, ale jego wykorzystanie wymaga posiadania przynajmniej podstawowej wiedzy o prawie konstytutywnym modelu zarysowanego betonu.

  • Praseodymium substituted lanthanum orthoniobate: Electrical and structural properties
    • Kacper Dzierzgowski
    • Sebastian Lech Wachowski
    • Weronika Gojtowska
    • Iga Lewandowska
    • Piotr Jasiński
    • Maria Gazda
    • Aleksandra Dorota Mielewczyk-Gryń
    2018 Full text CERAMICS INTERNATIONAL

    The results of ionic transport and structural measurements for the lanthanum orthoniobate doped by praseodymium are presented and discussed. The influence of calcium co-doping on these properties has also been analyzed. The results suggest the predominant protonic conductivity for the investigated system in the whole range of investigated temperatures. The influence of calcium co-doping on phase purity is analyzed.

  • Prawne i zarządcze uwarunkowania skutecznej restrukturyzacji jako instytucji zapobiegającej upadłości przedsiębiorstw - perspektywa krajowa i benchmarki zagraniczne
    • Przemysław Banasik
    • Sylwia Morawska
    • Błażej Prusak
    • Paweł Antonowicz
    • Małgorzata Chruściak
    2018 Zarządzanie i Finanse

    Artykuł omawia podstawowe ścieżki restrukturyzacji w sądzie przedsiębiorcy niewypłacalnego i zagrożonego niewypłacalnością.

  • Preconditioners with Low Memory Requirements for Higher-Order Finite-Element Method Applied to Solving Maxwell’s Equations on Multicore CPUs and GPUs
    • Adam Dziekoński
    • Grzegorz Fotyga
    • Michał Mrozowski
    2018 Full text IEEE Access

    This paper discusses two fast implementations of the conjugate gradient iterative method using a hierarchical multilevel preconditioner to solve the complex-valued, sparse systems obtained using the higher order finite-element method applied to the solution of the time-harmonic Maxwell equations. In the first implementation, denoted PCG-V, a classical V-cycle is applied and the system of equations on the lowest level is solved exactly. The second variant involves an approximate solution to the system of equations on the lowest level. To this end, auxiliary space preconditioning (ASP) is used instead of a direct solution. In this approach, denoted PCG-V-ASP, the time needed to solve the sparse system of equations is longer, but the memory requirements are smaller. To accelerate the computations, a graphics processing unit (GPU, Pascal P100) was used for both variants of the multilevel preconditioner. As a result, significant speedups were achieved over the reference parallel implementation using a multicore central processing unit (CPU, Intel Xeon E5-2680 v3, twelve cores). The results indicate that the auxiliary space preconditioning does in fact reduce the memory requirements, as compared with the reference PCG-V method, and at the same time performs each iteration faster. However, if symmetry is taken into account and the memoryefficient supernodal LDLT factorization is employed, the savings are less spectacular than anticipated based on previously published results using LU factorization and the multifrontal technique. PCG-V also requires a fewer iterations, so it’s time to solution is ultimately shorter. The difference is more pronounced if both preconditioners are run on a CPU. The use of a GPU as an accelerator for the computations considerably improves the performance of PCG-V-ASP over that of PCG-V.

  • Predicting the impact of traffic–induced vibrations on buildings using artificial neural networks
    • Anna Jakubczyk-Gałczyńska
    2018 Full text MATEC Web of Conferences

    Traffic–induced vibrations may constitute a considerable load to a building, cause cracking of plaster, cracks in load–bearing elements or even a global structural collapse of the whole structure [1-4]. Vibrations measurements of real structures are costly and laborious, not justified in all cases. The aim of the paper is to create an original algorithm, to predict the negative dynamic impact on the examined residential building with a high probability. The model to forecast the impact of vibrations on buildings is based on artificial neural networks [5]. The author’s own field studies carried out according to the Polish standard [6] and literature examples [7- 10] have been used to create the algorithms. The results of the conducted analysis show that an artificial neural network can be considered a good tool to predict the impact of traffic–induced vibrations on residential buildings, with a sufficiently high reliability.

  • Prefabrykacja żelbetowych segmentów duńskiego mostu w Szczecinie – wymagania i realizacja
    • Konrad Kisielewski
    • Marzena Kurpińska
    • Michał Witek
    2018 Full text Magazyn Autostrady

    W artykule opisano produkty wybrane do realizacji budowy drogi dwupasmowej oraz przeprawy mostowej przez Roskilde Fjord w Danii. Omówiono również wyzwania, z jakimi musieli zmierzyć się dostawcy podczas realizacji zamówienia.

  • Preferences and Transport Behavior of Gdansk Residents in the Light of the Result of Complex Traffic Survey
    • Krzysztof Grzelec
    • Katarzyna Hebel
    2018

    Preferences and transport behavior of the population are a fundamental aspect of research in public transport. Identifying the basic postulates of transport, the factors determining the specific behavior of transport and modal split allow to analyze the differences between the groups singled passengers and to prepare better offer of an urban transport. In Poland, still in many cities urban transport research is conducted ad hoc, in a situation when you need to carry out specific investment projects. Meanwhile, transportation demand and preferences and behavior of the inhabitants should be carried out regularly every 2 years, not less than 5 years. In Gdansk, transportation preferences and travel behavior of residents of Gdansk is carried out every 5 years as part of the Complex Traffic Survey (CTS). The objective of this article is to present and compare the results of CTS conducted in 2009 and 2016. The basic of the analysis is the thesis that the preferences and transport behavior of Gdansk residents have changed.

  • Preferences Towards Working in Culturally Diverse Teams at Different Stages of the Entrepreneurial Process
    • Katarzyna Stankiewicz
    • Paweł Ziemiański
    2018 Full text Problemy Zarządzania

    As entrepreneurial teams become prevalent, it is important to study factors related to their creation and effectiveness. The goal of the current research was to analyze preferences towards working in a multicultural team (MCT) versus a single culture team (SCT) at different stages of the entrepreneurial process. The study involved students originating from various cultures with previous experience in both SCTs and MCTs as participants. The preference towards working in a multicultural team was found to be stronger during preliminary stages of an entrepreneurial process. On the other hand, realization and assessment was in turn more strongly related with the preference towards working in a single culture team. The relationship between these preferences and the declared level of previous experience obtained in an MSC, and an SCT was also investigated. Obtained results are used to indicate possible directions for future research. Keywords: Entrepreneurial Team, Team Diversity, Multicultural Teams, Entrepreneurial process

  • Preliminary estimation of groundwater recharge on Brda river outwash plain
    • Anna Gumuła-Kawęcka
    • Adam Szymkiewicz
    • Beata Jaworska-Szulc
    • Małgorzata Pruszkowska-Caceres
    • Wioletta Gorczewska-Langner
    2018 Full text E3S Web of Conferences

    Estimation of groundwater recharge is one of the most challenging subjects in hydrogeology. It is a critical factor influencing the pollution migration, assessment of aquifer vulnerability to contamination, small-scale groundwater budget calculation, modeling of nutrient cycling and detailed flow path calculations. In Poland an infiltration rate method is widely used, which depends on a system of rate coefficients referring to the type of soil in the vadose zone and shows which part of the precipitation actually reaches the water table. The paper presents results of numerical simulations of vertical flow in unsaturated zone of an experimental site located on Brda outwash plain. Two simulations for varying vegetative cover (pine forest and grass) were performed. The results were compared with five infiltration rates classifications.

  • Preliminary study on icebreaking operation on the Middle and Lower Odra River
    • Tomasz Kolerski
    2018 Full text

    The Odra-Vistula Flood Management Project (OVFMP) is implemented with the assistance of international financial institutions, including the International Bank for Reconstruction and Development and the Council of Europe Development Bank, as well as with the support of funding from the Cohesion Fund and the state budget. Aside from others, the objective of the OVFMP is to increase flood protection for people living in selected areas of the Odra and Upper Vistula basins. The Odra-Vistula Flood Management Project consists of 5 components. In this paper the Component 1, Flood protection of the Middle and Lower Odra River will be discussed. This component aims to enhance protection against summer floods and winter floods to the cities and smaller towns located along the Odra River. The activities will include, among others, the (re)construction of dikes and other bank protective works, dredging of the Odra riverbed and its channels, river training works, and the reconstruction of spur dikes. All mentioned works will be carried out to ensure the safety of icebreaking operation which requires sufficient depth over the entire river course. Five bridges also need to be raised to facilitate safe passage of icebreakers. Within Lower and Middle Odra River the most significant flood risk is posed, in winter conditions, by ice jams created when flowing ice is stopped by existing obstacles such as shallow areas in the riverbed, narrowing of the riverbed and other obstacles caused by a result of sudden changes of the river current, backwater from sea waters and northern winds, which contribute to creation of ice jams (Lower Odra River runs a typically meridional course). This in turn causes damming of water and flooding of adjacent areas. The main aim of proposed tasks is to reduce possibility of creation of ice jams and to enable icebreaking which is the most efficient tool for minimizing risks of winter floods. These tasks will ensure safe passage of ice down the river and at the same time reduction of flood risk to adjacent areas.

  • Preparation and characterization of biodegradable and compostable PLA/TPS/ESO compositions
    • Agnieszka Haryńska
    • Maciej Sienkiewicz
    • Justyna Kucińska-Lipka
    • Helena Janik
    2018 Full text INDUSTRIAL CROPS AND PRODUCTS

    In this study, biodegradable and compostable compositions, derived from totally natural feedstock/raw materials, namely polylactide (PLA), potato thermoplastic starch (TPS) and plant glycerin have been made by melt extrusion with epoxydized soybean oil (ESO) as reactive modifier in order to improve PLAs ductility and reduce the products cost without compromising biodegradation. The obtained PLA/mTPS(0,5ESO)[75/25] and PLA/ mTPS(2ESO)[75/25] compositions provides satisfactory mechanical properties comparable to native PLA. Addition of 25% TPS and 0,5-2% ESO to PLA, improved impact strength from 13,70 kJ/m2 to 16,69 kJ/m2 compared to neat PLA and increase elongation at break from 2,6% to 8,8%. The addition of ESO into PLA/TPS composition enhanced water resistance and improved impact strength to over 16 kJ/m2 for PLA/TPS(2%ESO)[75/25] composition. The thermal, rheological and morphology of fractured surface were also studied. Finally, biodegradability and compostability of prepared samples was specified by stimulated composting process (according to PN-EN 14806:2010 standard). Possibility of replacing up to 25% of PLA by TPS and ESO, allows to reduces the costs of the product as well as maintain quite similar properties and ability to composting relative to native PLA.

  • Preparation and characterization of dummy-template molecularly imprinted polymers as potential sorbents for the recognition of selected polybrominated diphenyl ethers
    • Mariusz Marć
    • Aneta Panuszko
    • Jacek Namieśnik
    • Piotr Paweł Wieczorek
    2018 Full text ANALYTICA CHIMICA ACTA

    The main aim of this work was to conduct the preliminary/basic research concerning the preparation process of a new dummy molecularly imprinted polymer (DMIP) materials. Developed DMIPs were proposed as a sorption material in solid-phase extraction (SPE) technique for recognition of selected low mass polybrominated diphenyl ethers (PBDEs) e PBDE-47 and PBDE-99. Four new DMIPs were synthesized employing bulky polymerization technique by application of structural analogue of low mass PBDEs - 4,40-Dihydroxydiphenyl ether, as a dummy template. The DMIPs and corresponding nonimprinted polymers were prepared using different functional monomers: methacrylic acid; methyl methacrylate and different porogen agents: acetonitrile and tetrahydrofuran. The polymerization reaction was thermally initiated with 1,10-azobis (cyclohexanecarbonitryle). Ethylene glycol dimethacrylate was applied as a cross-linker. To optimize geometries and to calculate energies of the respective template-monomer complexes, the computational molecular modeling method was employed. The particles morphology and physicochemical characteristics of developed DMIPs and their equivalent NIPs were performed using nitrogen sorption porosimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy. The sorption capacities of prepared DMIPs and corresponding NIPs were studied using standard binding test. The adsorption capability studies give a possibility to assess the imprinting factor (IF) values, which were in the range from 1.1 to 4.0, depending on the DMIP type.

  • Preparation and characterization of natural rubber composites highly filled with brewers' spent grain/ground tire rubber hybrid reinforcement
    • Łukasz Zedler
    • Xavier Colom
    • Mohammad Saeb
    • Krzysztof Formela
    2018 COMPOSITES PART B-ENGINEERING

    Brewers' spent grain (BSG) and ground tire rubber (GTR) were applied as low-cost hybrid reinforcement natural rubber (NR). The impact of BSG/GTR ratio (in range: 100/0, 75/25, 50/50, 25/75 and 0/100 phr) on processing and performance properties of highly filled natural rubber composites was evaluated by oscillating disc rheometer, Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, swelling behavior, tensile tests and impedance tube measurements. It was found that increasing content of GTR in NR/BSG/GTR composites accelerate cross-linking reactions during their preparation, which resulted in decrease of scorch time and optimal cure time. Simultaneously, higher content of GTR filler in NR/BSG/GTR composites significantly improved their physico-mechanical, thermal, morphological and acoustical properties. This indicates better compatibility between natural rubber matrix and GTR than with BSG, which is related to correlation between two factors. First factor is obvious differences in particles size and polarity of GTR and BSG, which affected physical interactions into phase boundary between NR matrix and BSG/GTR hybrid reinforcement. Second factor is possible migration of unreacted curing additives and carbon black particles from GTR filler to NR matrix, which played a significant role on processing and final properties of NR/BSG/GTR composites.

  • Preparation of bicyclic β-lactam and bicyclic 1,3- oxazinone scaffolds using combined cycloaddition and metathesis processes
    • Anna Zakaszewska
    • Ewelina Najda-Mocarska
    • Sławomir Makowiec
    2018 Full text SYNTHETIC COMMUNICATIONS

    A simple, efficient two-step method for the preparation of heterobicyclic compounds was developed. Starting from 5-acyl or 5-carbamoyl-2,2- dimethyl-1,3-dioxa-4,5-dione bicyclic scaffolds of 1-azabicyclo[5.2.0]non- 3-en-9-one, 6,9,10,10a-tetrahydro-4H-[1,3]oxazino[3,2-a]azepin-4-one, and 6,9,10,10a-tetrahydro-2H-[1,3]oxazino[3,2-a]azepine-2,4(3H)-dione were prepared using cycloaddition of thermally generated ketenes to aldimines with unsaturated side chains, followed by metathesis. The method was applied to ring closing metathesis (RCM) of different heterocyclic substrates to demonstrate its versatility..

  • Pre-selection and assessment of green organic solvents by clustering chemometric tools
    • Marek Tobiszewski
    • Miroslava Nedyalkova
    • Sergio Madurga
    • Francisco Pena-Pereira
    • Jacek Namieśnik
    • Vasil Simeonov
    2018 ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

    The study presents the result of the application of chemometric tools for selection of physicochemical parameters of solvents for predicting missing variables – bioconcentration factors, water-octanol and octanol-air partitioning constants. EPI Suite software was successfully applied to predict missing values for solvents commonly considered as “green”. Values for logBCF, logKOW and logKOA were modelled for 43 rather nonpolar solvents and 69 polar ones. Application of multivariate statistics was also proved to be useful in the assessment of the obtained modelling results. The presented approach can be one of the first steps and support tools in the assessment of chemicals in terms of their greenness.

  • Pressure drop related to flow maldistribution in a model minichannel plate heat exchanger
    • Michał Klugmann
    • Paweł Dąbrowski
    • Dariusz Mikielewicz
    2018 Full text Archives of Thermodynamics

    The paper describes the issues related to the pressure drop that accompanies the phenomenon of maldistribution of working fluid between the channels of a model minichannel plate heat exchanger. The research concerns a single exchanger's plate containing 51 (in every geometry) parallel rectangular minichannels of hydraulic diameters 461 µm, 571 µm, 750 µm and 823 µm. In addition, the more complex geometry has been investigated, equipped with additional diagonal channels (so called extended geometry). The moment of the liquid phase transition through the heat exchanger was recorded at the flow rates from 0.83 g/s to 13.33 g/s in the inlet manifold. The article discusses the total pressure drop as a function of the flow rate and the characteristic dimension of minichannels, as well as the pressure drop as a function of the time of the fluid passage through the main part of the measuring section in which measurements were done. The resulting profiles correlate with the images of the flow distribution between channels recorded using the fast shutter speed camera, that allows to draw a further conclusions about the specifics of the maldistribution process. The impact of the total pressure drop on the actual range of optimum operating conditions of the heat exchanger was analyzed.

  • Pre-swirl energy saving device in marine application
    • Przemysław Król
    • Krzysztof Tesch
    2018 Full text Journal of Physics : Conference Series

    This paper covers topics of energy saving device (ESD) with application to marine propulsors. The form of ESD, considered in this paper, consists of fixed lifting foils mounted in front of the screw propeller (the pre-swirl stator/guide vanes). An algorithm for designing propulsion systems, consisting of guide vanes and screw propeller, is presented. The proposed method relies on hybrid lifting line (guide vanes)-lifting surface (screw propeller) vortex model. Additionally, an analysis method for such systems is also presented. It utilises lifting surface model for guide vanes as well as for screw propeller blades. Accuracy of the proposed method is notably lower in comparison with CFD calculations, however, the former is substantially faster and at the same time capable of providing accuracy sufficient for practical application. Further, the entire process of design and analysis is presented on the example of Nawigator XXI ship. The designed propulsion system, consisting of propeller CP753 and pre-swirl stator ST002, was manufactured and tested in model scale. Model tests revealed increased efficiency by 4% in the design point in comparison with with the Nawigator’s original propeller CP469. Finaly, model scale experimental results, conducted in Ship Hydrodynamics Division of CTO Gdansk, are compared with numerical predictions.

  • Pretreatment of Lignocellulosic Materials as Substrates for Fermentation Processes
    • Karolina Kucharska
    • Piotr Rybarczyk
    • Iwona Hołowacz
    • Rafał Łukajtis
    • Marta Glinka
    • Marian Antoni Kamiński
    2018 Full text MOLECULES

    Lignocellulosic biomass is an abundant and renewable resource that potentially contains large amounts of energy. It is an interesting alternative for fossil fuels, allowing the production of biofuels and other organic compounds. In this paper, a review devoted to the processing of lignocellulosic materials as substrates for fermentation processes is presented. The review focuses on physical, chemical, physicochemical, enzymatic, and microbiologic methods of biomass pretreatment. In addition to the evaluation of the mentioned methods, the aim of the paper is to understand the possibilities of the biomass pretreatment and their influence on the efficiency of biofuels and organic compounds production. The effects of different pretreatment methods on the lignocellulosic biomass structure are described along with a discussion of the benefits and drawbacks of each method, including the potential generation of inhibitory compounds for enzymatic hydrolysis, the effect on cellulose digestibility, the generation of compounds that are toxic for the environment, and energy and economic demand. The results of the investigations imply that only the stepwise pretreatment procedure may ensure effective fermentation of the lignocellulosic biomass. Pretreatment step is still a challenge for obtaining cost-effective and competitive technology for large-scale conversion of lignocellulosic biomass into fermentable sugars with low inhibitory concentration.

  • Prevalence Problem in the Set of Quadratic Stochastic Operators Acting on L1
    • Krzysztof Bartoszek
    • Małgorzata Pułka
    2018 Bulletin of the Malaysian Mathematical Sciences Society

    This paper is devoted to the study of the problem of prevalence in the class of quadratic stochastic operators acting on the L1 space for the uniform topology. We obtain that the set of norm quasi-mixing quadratic stochastic operators is a dense and open set in the topology induced by a very natural metric. This shows the typical long-term behaviour of iterates of quadratic stochastic operators.