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  • Festiwal Sztuki Efemerycznej "Konteksty" Sokołowsko 2017
    • Patryk Różycki
    2017

  • Fiasko projektu inwestycyjnego spowodowane błędami rozpoznania stanu technicznego obiektu i wykonanej dokumentacji projektowej
    • Dariusz Kowalski
    2017 Materiały Budowlane

    Realizacja przedsięwzięć inwestycyjnych w istniejących obiektach budowlanych związana jest z koniecznością wykonania rzetelnej weryfikacji ich aktualnego stanu technicznego, użytych materiałów, wprowadzonych zmian oraz uszkodzeń powstałych w czasie eksploatacji. Pozyskane informacje są podstawą do podejmowania decyzji zarówno technicznych, jak i ekonomicznych związanych z planami inwestycyjnymi. Błędy popełnione przez inżynierów przyczyniły się do podjęcia niewłaściwych decyzji, które skutkowały problemami już przy pierwszych pracach budowlanych w obiekcie. Po ujawnieniu jego rzeczywistego stanu technicznego proces inwestycyjny został wstrzymany, a istniejąca substancja techniczna obiektu nie przedstawiała w odkrytym stanie żadnej wartości materialnej, którą warto byłoby ratować.

  • Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete
    • Józef Judycki
    • Mariusz Jaczewski
    • Dawid Ryś
    • Marek Pszczoła
    • Piotr Jaskuła
    • Adam Glinicki
    2017 Pełny tekst IOP Conference Series: Materials Science and Engineering

    High Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article presents the comparison of performance of pavements constructed in typical contract conditions with the road bases made of HMAC and conventional asphalt concrete (AC). The field investigation was focused on the number of low-temperature cracks, bearing capacity (based on FWD test) of road sections localized in coldest region of Poland. Also load transfer efficiency of selected low-temperature cracks was assessed. FWD test confirmed lower deflections of pavements with HMAC and two times higher stiffness modulus of asphalt courses in comparison to pavements constructed with conventional AC mixtures. Relation of stiffness of asphalt layers and amount of low-temperature cracks showed that the higher stiffness modulus of asphalt layers could lead to increase of the number of low-temperature cracks. FWD test results showed that the load transfer efficiency of low-temperature cracks on pavements with HMAC presents very low values, very close to lack of load transfer. It was surprising as section with HMAC road base were aged from 2 to 5 years and presented very good bearing capacity.

  • Field tests on hydrodynamic and hybrid operation of a bi-directional thrust bearing of a pump-turbine
    • Leszek Dąbrowski
    • Michał Wasilczuk
    • Michał Wodtke
    2017

    In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Because of bi-directional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand availability of experimental field data on bearing operation is limited for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have done in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data.

  • Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine
    • Michał Wasilczuk
    • Michał Wodtke
    • Leszek Dąbrowski
    2017 Pełny tekst Lubricants

    In vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The research into fluid film thrust bearings has been quite extensive over the years, comprising theoretical studies of bearing properties with the use of more and more sophisticated calculation codes. On the other hand, the availability of experimental field data on bearing operation is limited, for obvious reasons. In this paper the authors present part of the results of extensive field tests of a large bearing of a pump-turbine they have conducted in a pumped storage power plant. Hopefully this data will be of interest to other researchers to compare theoretical predictions to measurement data.

  • Filtracja danych TDOA w filtrze UKF w systemie multilateracyjnym
    • Paweł Tomasz Kosz
    • Jarosław Sadowski
    • Jacek Stefański
    2017 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono implementację metody filtracji danych pomiarowych w systemie MLAT(Multilateration), która ma na celu zwiększenie dokładności estymacji położenia poruszającego się statku powietrznego poprzez kompensację błędów pomiarowych. Opisano sposób implementacji algorytmu bezśladowego filtru Kalmana dla danych pomiarowych TDOA (Time Difference of Arrival), a następnie na podstawie zarejestrowanych rzeczywistych tras lotu statku powietrznego dokonano weryfikacji przydatności stosowania tego typu algorytmu.

  • FINANCIAL COMPARISON OF WESTERN BALKAN AND BALTIC SEA STATES USING THE CAMEL APPROACH
    • Katarzyna Kubiszewska
    2017 Pełny tekst International Business and Global Economy

    • The aim - This article aims to compare the situation in the banking sectors of two regions, which due to their political and economic history have much in common. These are the Western Balkan States of Serbia, Croatia and Macedonia, and the Baltic Sea States of Lithuania, Estonia, and Latvia. • Methods - It presents three approaches to defining banking stability that can be found in the literature and carries out an initial analysis of the financial performance of the chosen banking sectors using the CAMEL approach. • Outcomes: Although in 2010, the banking sectors from the Baltic Sea States were in a relatively worse shape than the Western Balkan States, it was proved that the banking sectors in countries where economic transformation is recognized as completed could achieve a faster recovery from the crisis in comparison to states which are still undergoing this process • Conclusions – The transformation process is essential for further building a market economy and the quicker is completed the quicker the banking sector can develop and the easier it is to recover from a possible crisis or external shocks.

  • Financial markets diffusion patterns. The case of Mexican investment funds
    • Adam Marszk
    • Ewa Lechman
    • Harleen Kaur
    2017 Pełny tekst EQUILIBRIUM Quarterly Journal of Economics and Economic Policy

    Exchange traded funds (ETFs) are one of the most influential financial innovations, reshaping the investment funds market in many countries, including Mexico. Due to their similar investment objectives, ETFs are considered substitutes for mutual funds. The aim of the article is to provide an in-depth insight into the issues associated with the development of financial markets in Mexico over the period 2002-2012, putting special emphasis on the development patterns of ETFs. First we use descriptive statistics to unveil basic changes and trends in the Mexican investment funds (ETFs and mutual funds). Then we use a category of the innovation diffusion models, i.e. logistic growth models, in order to explore the key development patterns. Data sources and methodological framework are presented in the second section of the article, with a detailed description of the innovation diffusion models applied in the research (based on 3-parametric logistic curve). The sum of assets under management of ETFs and mutual funds is considered as the size of the total investment funds market. Empirical findings indicate a significant development of the ETF market, both in terms of assets under management and market share. According to the presented estimations, Mexican ETF market development can be described with the logistic growth models, and three characteristic phases of the logistic curve were clearly observable. The predicted ETF market development patterns point towards a further increase of the market share of ETFs over the next 3-5 years, yet the probability of exceeding the level of ca. 20-30% seems low.

  • First Outcomes of an Investigation about Daylighting Knowledge and Education in Europe
    • Giuliani Federica
    • Natalia Sokół
    • Viula Raquel
    • Valerio R.M. Lo Verso
    • Helena Coch Roura
    • Federica Caffaro
    2017 Pełny tekst

    DAYKE (Daylighting Knowledge in Europe) is a project to investigate the daylighting knowledge and skills of Architecture students and practitioners from different countries within the European Union. This paper introduces the first stage of the research and provides results from a direct survey taken by 161 students from seven schools of Architecture: two in Italy, one in The Netherlands, two in Poland and two in Spain. The results indicate significant national differences in preference and perception of daylit spaces. They also show a lack of knowledge about daylighting metrics and regulations among the respondents. Although the research is undergoing, the preliminary data analysis indicates that there is a need for enhancing the daylight knowledge among future architects.

  • Fish gelatin-nanoclay films. Part I: Effect of a kind of nanoclays and glycerol concentration on mechanical and water barrier properties of nanocomposites
    • Hanna Staroszczyk
    • Edyta Malinowska-Pańczyk
    • Karolina Gottfried
    • Ilona Kołodziejska
    2017 JOURNAL OF FOOD PROCESSING AND PRESERVATION

    The aim of work was the improvement of the mechanical and water barrier properties of nanocomposites prepared from fish gelatin and nanoclays (5–15%), plasticized with glycerol at different concentrations. The effect of hydrophilic Cloisite Na1 and Nanomer®PGV was compared with that exerted by organically modified more hydrophobic Nanofil®2 and NanoBent ZR-1. Antimicrobial activity of nanocomposites containing hydrophobic nanoclays was also investigated. In a nanocomposite with 5% Cloisite Na1 and 15% glycerol, the Tensile strength (TS) was by 20% higher than that for plasticized films without nanoclay. The improvement of TS was also evidenced for plasticized nanocomposites containing 5% of hydrophobic NanoBent ZR-1 and Nanofil®2. Nanocomposites containing 5% of Cloisite Na1 with 15% glycerol, and these containing 5% Nanofil ®2 or NanoBent ZR-1 with 20% glycerol, showed 23% and about 15%, respectively, lower water vapor permeability than gelatin films. Gelatin-NanoBent ZR-1 nanocomposite caused complete inactivation of gram-positive bacteria S. aureus and L. innocua.

  • Five-phase Induction Motor Drive Operation During Stator Phase Fault
    • Filip Wilczyński
    • Patrick Strankowski
    • Jarosław Guziński
    • Marcin Morawiec
    • Arkadiusz Lewicki
    • Grzegorz Andrzej Kostro
    2017 Automatyka Elektryka Zakłócenia

    The article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.

  • Flavones in cocoa defence against Phytophthora megakarya
    • Emile Minyaka
    • Claude Simo
    • Barbara Kusznierewicz
    • Banen Madina
    • Piau Mouen
    • Nicolas Niemenak
    • Ndoumou Omokolo
    2017 Pełny tekst Research & Reviews: Journal of Botanical Sciences

    Cross-pollination of suitable genotypes and earlier selection of elite offspring using adequate plants-associated defence markers in plantlets leaves are decisive for development of T. cacao genotypes tolerant to black pods disease (BPD). T. cacao plantlets from manual cross-pollination of ♀SNK64 × ♂UPA143 were analyzed for their susceptibility to BPD using leaf disc test. Subsequently, leaves (healthy, wounded and wound+infected) of selected E9 (tolerant), E13 (moderate susceptible) and E32 (most susceptible) young hybrid genotypes from ♀SNK64 × ♂UPA143 were used for flavones analysis using a HPLC/LC/MS system. Leaf disc test showed 62.5% of the progeny with disease score rates lower than the mean value of both parents. About 79.17% and 20.83% of the progeny were lesser susceptible than the most susceptible parent (UPA143) and the tolerant parent (SNK64) respectively. Total flavones contents were abiotic and biotic stresses dependant. Under infection, tolerant hybrid genotype (E9) displayed the highest flavones contents, which might control tolerance to BPD. Individual flavones analysis revealed differential patterns depending on flavones, treatment and hybrid genotype. Luteolin rutinoside isomer (tR=12.5), isoorientin (tR=12.0) and apigenin-pentosyl-hexoside (tR=10.9) appeared to be characteristic of tolerant hybrid genotype (E9) during infection. Reversely, high content of Apigenin-hexoside (tR=10.1) and apigenin-hexoside (tR=11.6) might be associated to the susceptible hybrid genotypes (E13) and(E32). Hence, ♀SNK64 × ♂UPA143 could be used to develop hybrid genotypes tolerant to BPD. Pools of above flavones, reported here for the first time in T. cacao defence, might be useful markers to develop T. cacao hybrid genotypes tolerant to BPD.

  • Flexible dye-sensitized solar cells based on Ti/TiO2 nanotubes photoanode and Pt-free and TCO-free counter electrode system
    • Maciej Klein
    • Mariusz Szkoda
    • Miroslaw Sawczak
    • Adam Cenian
    • Anna Lisowska-Oleksiak
    • Katarzyna Siuzdak
    2017 SOLID STATE IONICS

    Flexible dye-sensitized solar cells (DSSCs) are getting more attention compared to standard glass covered DSSCs due to their unique commercial applications (e.g. tents or sail surfaces) and the possibility of rolling up into a small, portable device. In this work, titania nanotubes (TiO2 NT) modified with titania nanoparticles (TiO2 NP) were photoelectrochemically characterized as an anode for flexible dye-sensitized solar cells. The morphology of the prepared electrode materials was inspected using scanning electron microscopy. Electrochemical activity of titania in contact with anaqueous electrolyte containing iodine species was investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA). The anode with deposited TiO2 NP exhibits enhanced efficiency of photocurrent generation in comparison to pure titania NT. The new type of comb-shaped Ti electrode with poly(3,4-ethylenedioxythiophene):poly(2-styrenesulphonate) (pEDOT:PSS) layer deposited onto the PET foil substrate was proposed as a counter electrode and compared with a conventional Pt catalytic layer as well as with a typical Pt/FTO counter electrode. Overall photoconversion efficiency of pEDOT-based counter-electrode DSSC reached 0.61% and was almost 40% higher than for counter electrode with Pt.

  • FLOOD MANAGEMENT IN URBAN BASINS OF THE CITY OF GDAŃSK
    • Tomasz Kolerski
    • Dominika Kalinowska
    2017

    Over the last years, the City of Gdańsk suffers twice from flash floods. Both events were caused by intense storms which produced significant surface runoff and caused inundation private and cities properties. The first case of July 2001 flood [3], [9] was the turning point for the city authorities, who decide to look close on the flood management in small urban catchments. The aim of research projects was to establish technical solutions and procedures to be applied in case of risk of flooding due to heavy rain on all Radunia Channel tributaries. The largest basin is the catchment of the Oruński Stream. This area was recently intensely developed and according to the spatial planning the urbanisation process will proceed. The project’s closure took form of decisions concerning technical solutions modifying operation mode of Gdansk Water Junction System in order to ensure an optimal distribution of flood water. After 2003, Gdansk Floodway System rebuilding propositions started to be regularly implemented. Thanks to actions initiated in the river basin of Radunia channel, no more emergency situations were observed during the flood in 2016. In the paper, the hydrologic model of the water system of Oruński Stream will be presented with particular effort paid to the new and renovated retention structures. Hydrological modelling system of HEC HMS was used to simulate the basin response on precipitation. The 16,4 km2 model domain was divided into 35 sub-basins according to storm water drainage system. Both, current and proposed land use of the basin was taken into consideration. The operation of six existing and two proposed flood detention reservoirs were included in the simulations. The results showed the importance of reservoirs and water diversion structures on flood surge routing.

  • Flow Analysis of a Kaplan Turbine
    • Marzena Banaszek
    • Zbigniew Krzemianowski
    2017

    This monograph is a guide to a method of experimental and numerical flow investigations for Kaplan - type turbines. The numerical calculations were compared with the test results of the model Kaplan turbine. The tests were carried out on the model test rig in the Gdańsk University of Technology. The turbine has been thoroughly experimentally investigated, resulting in the identification of optimum setting combination of the stator and rotor. This experimentally determined efficiency-optimal work point has been taken as the basis of numerical modeling. For the optimal operating point, the numerical analysis was conducted for a lot of different turbulence models. The methodology of Kaplan cam curve determination by CFD application has been presented with great respect to the local phenomena of the flow and global operating parameters of the turbine.

  • Fluctuation-enhanced and conductometric gas sensing with nanocrystalline NiO thin films: A comparison
    • Umut Cindemir
    • Maciej Trawka
    • Janusz Smulko
    • Claes-Göran Granqvist
    • Lars Österlund
    • Gunnar Niklasson
    2017 SENSORS AND ACTUATORS B-CHEMICAL

    Nanocrystalline thin films of NiO were prepared by advanced reactive gas deposition, and their responses to formaldehyde, ethanol and methane gases were studied via fluctuation-enhanced and conductometric methods Thin films with thicknesses in the 200–1700-nm range were investigated in as-deposited form and after annealing at 400 and 500 °C. Morphological and structural analyses showed porous deposits with NiO nanocrystals having face-centered cubic structure. Quantitative changes in frequency-dependent resistance fluctuations as well as in DC resistance were recorded upon exposure to formaldehyde, ethanol and methane at 200 °C. The response to formaldehyde was higher than that to ethanol while the response to methane was low, which indicates that the NiO films exhibit significant selectivity towards different gaseous species. These results can be reconciled with the fact that formaldehyde has a nucleophilic group, ethanol is an electron scavenger, and methane is hard to either reduce or oxidize. The gas-induced variations in DC resistance and resistance fluctuations were in most cases similar and consistent.

  • Footbridges. Dynamic Design – Selected Problems
    • Krzysztof Żółtowski
    • Mikołaj Binczyk
    • Przemysław Kalitowski
    2017

    Modern footbridges create challenge in esthetic and structural design. Breaking the proven canons is a recipe for architectural success. However esthetic form has to be also a functional pedestrian bridge. Therefore a good FEM modeling is a key element in engineering part of design. The paper presents selected problems related to the modeling of the dynamic construction of footbridges. Several basic dynamic problems concerning numerical methods in analysis and preliminary design of structure are discussed: • Numerical models of structure and discussion of their effectiveness. • Time-step Newmark method. Validation of parameters of method (time-step, damping). • Non linear geometric effects in dynamics. • Vertical and horizontal excitation - cause of vibrations. • Intelligent load. • Dynamic tuning of structure. On the base of presented set of actions several lively footbridges were analyzed, designed and constructed. Dynamic side test was often a final confirmation of the assumptions and methods predicted in designing process.

  • Forced vibrations in a dynamic system that is damped by a mechanism that trans-pass through its singular position
    • Krzysztof Lipiński
    2017

    In the paper, vibrations of a hybrid multibody-continuous system are investigated. For all the mechanical devices, effective damping methods are crucial in the design process. To obtain it, installation of viscous dampers or elasto-viscous elements is dominant. In the paper, an alternative method is investigated. It is based on modal disparity. To describe the method briefly, when structural damping is present in continuous systems, high frequency vibrations are better damped in general. To accelerate the low frequency damping, energy transfer between different modes can be helpful. Such transfer is impossible when linear systems are considered. It becomes possible, when nonlinear elements are present, e.g., when a mechanical system is introduced and it is set in its pose closed to its kinematical singular position. To test the hypothesis, a numerical model is proposed and tested. The mechanism is modelled as a multibody system composed of two rigid bodies. Joint displacements are considered as system generalized coordinates. The Newton/Euler’s equations are developed for free body diagrams, and then they are combined with the kinematics equations and projected on joint axes. To express dynamics of the continuous beam, finite elements are used. Deformations of a set of selected points (nodes) are considered as the coordinates. To joint the subsystems, constraint equations are introduced. Next, the Lagrange’s multipliers and the dependent coordinates are eliminated. Efficiency of free vibrations damping was verified in some earlier. Presently reaction of the system is tested for the forced vibrations, only. Unfortunately, in the presently considered case, the proposed system is less effective. Some reduction of the amplitude is observed for the forced vibrations. Range of the reduction is low. This damping method should not be recommended in case of forced vibrations. For the final recommendations, some additional investigations should be recommended to obtain better description of the phenomena present there.

  • Foreign Entry Modes of High-tech Firms in Poland
    • Nelly Daszkiewicz
    2017 Studia Universitatis Babes-Bolyai.Negotia

    The main objective of the article is to present the role and importance of foreign entry modes in internationalization process and their key determinants. Research methods: A quantitative research design was used. A survey was conducted on the sample of 263 firms operating in high‐tech industries in the territory of Poland. To verify the assumed hypotheses the statistical instruments were used including Chi‐Square test and Cramer's V contingency coefficient. Findings: The investigated high‐tech firms adopt a whole range of entry modes in their internationalization process. However, research results show that the choice of foreign entry modes is determined by the size of the company, pace of internationalization and internationalization intensity (measured by TNI index), namely bigger firms, born global and firms with high internationalization index are more likely to use more advanced and entry modes characterized by high‐control.

  • Formowanie wektorów napięcia wyjściowego w pięciofazowych falownikach napięcia
    • Arkadiusz Lewicki
    • Patrick Strankowski
    • Marcin Morawiec
    • Jarosław Guziński
    2017 Automatyka Elektryka Zakłócenia

    W falownikach pięciofazowych, załączenie wektorów aktywnych powoduje jednoczesne formowane dwóch, zależnych od siebie wektorów napięcia wyjściowego. Sterowanie pięciofazowymi silnikami indukcyjnymi wymaga, aby wektory te miały ściśle określone długości i położenia. Niezależne formowanie dwóch wektorów napięcia o parametrach określonych w układzie sterowania silnikiem wymaga zastosowania odpowiedniej strategii Modulacji Szerokości Impulsów MSI. W pracy zaprezentowano dwie metody formowania napięć wyjściowych w falownikach pięciofazowych. Oba rozwiązania umożliwiają niezależne formowanie dwóch wektorów napięcia przy zachowaniu wyższego priorytetu generowania napięcia pierwszej harmonicznej.