2017 - Repozytorium publikacji - Politechnika Gdańska

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The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.
- Karol Daszkiewicz
- Ghislain Maquer
- Philippe Zysset
2017 Biomechanics and Modeling in Mechanobiology
Boundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58 and 15.87mm) were cropped from μCT scans of femoral heads and vertebral bodies. They were converted into μFE models and their stiffness tensor was established via six uniaxial and shear load cases. PMUBCs- and KUBCs-based tensors were determined for each sample. “In situ” stiffness tensors were also evaluated for the embedded configuration, i.e. when the loads were transmitted to the samples via a layer of trabecular bone. The Zysset–Curnier model accounting for bone volume fraction and fabric anisotropy was fitted to those stiffness tensors, and model parameters ν0 (Poisson’s ratio) E0 and μ0 (elastic and shear moduli) were compared between sizes. BCs and sample size had little impact on ν0. However, KUBCs- and PMUBCs-based E0 and μ0, respectively, decreased and increased with growing size, though convergence was not reached even for our largest samples. Both BCs produced upper and lower bounds for the in situ values that were almost constant across samples dimensions, thus appearing as an approximation of the effective properties. PMUBCs seem also appropriate for mimicking the trabecular core, but they still underestimate its elastic properties (especially in shear) even for nearly orthotropic samples.
The effectivness of fault detection in common rail injectors examination methods
- Zbigniew Kneba
- Paweł Straszak
- Klaudia Jakubczyk
2017 Pełny tekst Combustion Engines
The article presents the effectiveness tests of fault detection in common rail injectors. 40 injectors with different wear levels were tested. Testing was made on two test benches of a completely different design. Research includes comparison of accuracy, reproducibility and testability to detect specific defects. A device was created for visualization of the fuel injector spraying steam.
The effects of bifunctional linker and reflux time on the surface properties and photocatalytic activity of CdTe quantum dots decorated KTaO3 composite photocatalysts
- Beata Bajorowicz
- Joanna Nadolna
- Wojciech Lisowski
- Tomasz Klimczuk
- Adriana Zaleska-Medynska
2017 APPLIED CATALYSIS B-ENVIRONMENTAL
Novel CdTe-KTaO3composite photocatalysts were successfully synthesized by using thioglycolic acid(TGA) or 3-mercaptopropionic acid (MPA) as linker molecules which facilitated attachment of CdTequantum dots to the surface of KTaO3nanocubes. The as-prepared photocatalysts were characterizedby UV–vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM) with energy dispersive X-ray analysis (EDX), Fouriertransform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) specific surface area, X-rayphotoelectron spectroscopy (XPS) and photoluminescence (PL) emission spectroscopy. The obtainedCdTe-decorated KTaO3composites showed greatly improved photocatalytic performance for degra-dation of toluene in the gas phase under LEDs light irradiation (max= 415 nm) over pristine KTaO3.TGA-functionalized CdTe-KTaO3composites exhibited higher photocatalytic activity as compared withMPA-capped CdTe-KTaO3hybrids which can be ascribed to the shorter chain length of TGA moleculeas compared with MPA linker and therefore faster electron transfer from TGA-CdTe nanodots toperovskite-type potassium tantalate. The significance of quantum size effect of CdTe QDs for enhancingphotocatalytic performance of CdTeQDs-decorated KTaO3was also discussed.
The effects of selected factors on pedestrian crossings in urban areas
- Lucyna Gumińska
2017 Pełny tekst MATEC Web of Conferences
Pedestrian crossings are designed to help pedestrians cross a road. There are at-grade pedestrian crossings with or without traffic lights and grade separated crossings such as subways and footbridges. Pedestrian crossings may be located next to a junction or on road sections between junctions. Where at-grade crossings are involved, pedestrians and motorists interact, which may lead to dangerous situations and road traffic conflicts. These mutual interactions between infrastructure users determine how pedestrian crossings operate. They also affect the operation of junctions, if located next to them. The article presents the most important factors that affect the operation of pedestrian crossings. Because of the multiplicity of factors, only one of the parameters of traffic factors is described in detail.
The Efficiency of Post‐Communist Countries’ Health Systems
- Justyna Kujawska
2017
Health‐care costs are a major financial burden for the transition economies, which have experienced rapidly increasing demand for health‐care services. The former communist countries of the Central and Eastern Europe and Central Asia needed to reform the financing of their health‐care systems and make efforts to strengthen the role of primary care while limiting the role of hospital care. The growing health needs and, consequently, costs resulted in the increased attention paid to the performance of health systems. The aim of this chapter is to determine the efficiency of health systems in post‐communist countries. The data envelopment analysis method was used. The effective health systems were identified and recommendations for the inefficient countries were formulated.
The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
- Łukasz Breńkacz
- Grzegorz Żywica
- Marta Drosińska-Komor
2017 Pełny tekst Polish Maritime Research
Hydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm. An impact hammer was used to excite vibration of the shaft. The approximation by means of the least squares method was applied to determine bearing dynamic coefficients. Based on the performed research, the four (i.e. two main and two cross- coupled) coefficients of stiffness, damping and mass for each bearing were obtained. The mass coefficients add up to the complex shaft weight. These values are not required for modeling dynamics of the machine because the rotor mass is usually known, however, they may serve as a good indicator to validate the correctness of the stiffness and damping coefficients determined. Additionally, the experimental research procedure was described. The signals of displacements in the bearings and the excitation forces used for determination of the bearing dynamic coefficients were shown. The study discussed in this article is about a rotor supported by two hydrodynamic bearings operating in a nonlinear manner. On the basis of computations, the results of bearing dynamic coefficients were presented for a selected speed
The experimental research on the axially compressed CFFT columns
- Piotr Korzeniowski
- Tomasz Ulenberg
2017
The research objectives is to test the behaviour of the axially compressed glass fiber reinforced polymer tubes CFFT (concrete-filled FRP tube) withe the R-C core.
The forecasted values of cutting power for sawing on band sawing machines for Polish Scots pine wood (Pinus sylvestris L.) in a function of its provenance.
- Daniel Chuchała
- Kazimierz Orłowski
- Tomasz Ochrymiuk
2017 Pełny tekst Annals of WULS, Forestry and Wood Technology
In this paper the predicted values of cutting power for band sawing machine (EB 1800, f. EWD), which is used in the Polish sawmills, were showed. The values of cutting power were forecasted for Scots pine (Pinus sylvestris L.) wood of five provenances from Poland. These values were determined using an innovative method of predicting the cutting power, which takes into account of elements of fracture mechanics. The resulting predictions compared with the values of cutting power derived from predictions using the classical method, which is based on the specific cutting resistance.
The forecasts-based instrument rule and decision making. How closely interlinked? The case of Sweden
- Karolina Tura-Gawron
2017 Pełny tekst EQUILIBRIUM Quarterly Journal of Economics and Economic Policy
Research background: The Central Bank of Sweden declared in years 1999–2006 the implementation of the Svensson’s concept of inflation forecast targeting (IFT). It means that the repo rate decision-making process depends on the inflation forecasts. The concept evolved from the strict IFT with the decision-making algorithm called ‘the rule of thumb’ to the flexible IFT. Purpose of the article: The aim of the article is to: (1) analyze the influence of the inflation rate and GDP growth rate on the repo rate decisions, (2) analyze the influence of the infla- tion rate and GDP growth rate forecasts (in two year horizon) on the repo rate decisions in Sweden in years 1999–2006. Methods: The analysis encompasses the repo rates decisions, CPI inflation rate, GDP growth rate, central paths of CPI inflation forecasts and central paths of GDP growth rate forecasts (the mode values) in the two years horizon published by The Central Bank of Sweden in years 1999–2006. The studies are based on the Taylor-type instrument rule and forecast-based Taylor-type instrument rule. The methodology used is multiple linear regres- sion models. Findings & Value added: The Central Bank of Sweden in years 1999–2006 implemented direct inflation forecast targeting (DIFT) rule. The decision-making algorithm was based on the CPI inflation forecasts and the rule of the thumb algorithm. The exact rule of the thumb was as follow: if the inflation forecast, in the tw o year forecast’s horizon exceeded the inflation target by 1 p.p., then the central bank raised the repo rate by 0.4 p.p; if it was below it, then the central bank reduced the repo rate by 0.4 p.p. If the inflation forecast was equal to the inflation target, then the repo rate remained unchanged. The historical repo rates differ from the theoretical estimated rule of the thumb’s repo rates by +/-0.28 p.p.
THE FUNCTION OF GREENERY IN A SKYSCRAPER: THE PLACEMENT AND ITS INFLUENCE
- Alicja Stefańska
- Daniel Załuski
2017
The contrast between the high rise buildings; with their mostly geometric shapes, and the organic form of the greenery was visible even in the idea of a skyscraper. Yet the realizations and recent projects show emerging interest and the link between them. To better understand the developing function of the greenery in the context of a skyscraper, both literature and case studies are conducted. The aim is to relate the location and type of the green structures to the function that it performs. The study examines the multiple functions of green structures and their influence on a building’s interior and its surroundings. The investigation shows that the role of green spaces is now more appreciated, and as a result, greenery is being utilized to an increasing extent. Inquiries into futuristic, albeit often unrealized projects highlight that not every location nor every merit of green structures is used. The available evidence shows that the function of greenery in the context of the skyscraper has changed together with its meaning to the people. It can serve multiple functions in various locations, making the megastructure an improved place for its users. Although, only some of them are recognisably efficient in regards to the scale of the building itself.
The function of the sculpture in public space and its reception occupants of the city
- Anna Stasiak
2017 Pełny tekst Przestrzeń i Forma
Sculpture has been with people for thousands of years. Its destiny, subject and scale have changed over the centuries. Public art, along with sculpture, began to appear in a new form (not only to commemorate important figures and events) only in the 1960s. This paper aims to answer what functions are currently performed by the sculptures located in a public space and how they are perceived by the inhabitants of the city.
The Future of the University? Social Activism among Young Polish Scholars
- Krzysztof Leja
- Anna M. Kola
2017
The question “Quo vadis, Academia?” is posed by scholars, research administrators, journalists and is also ofound in public opinion in Poland in different contexts. Authors of the article do not call into question the necessity of changes of contemporary universities, but they think that the source of changes should be characterized by a bottom-up approach, especially by those who have already achieved extraordinary scientific success and understand the requirement for “creative destruction” of traditional forms of the university (seen as an organization). Changes in university should not be a result of administrators’ and university managers’ decisions (as a top-down approach), but rather should be initiatives caused by the academic community. These engaged initiatives might take different forms – associations, foundations and membership in academic committees as well as different kinds of new social movements. An example of such a social movement is Obywatele Nauki (the Citizens of Academia). Its members are young (usually postdoctorates), as well as more experienced scholars, who – despite the fact of achieving scientific and academic success – are working for the common good and the good of the university, which is seen as an important social institution. One of the goals of the movement is to defy the process of the “de-universitification” of universities. They are against the idea and practice of the neo-liberal university, led by the idea of profit, what is measured by the effectiveness of commercialization of achievements. Authors of the article present ethnographically inspired research among the representatives of the movement. The researches were conducted using ethnographic and anthropological methodologies in the field of higher education studies (also as an action research). Therefore, methods used in this study were the following: interviews (IDI) with leaders and members of the movement and participant observation. An important aspect of the research in the context of conclusions and possible applications, but also for the conceptualization and operationalization of the research, is engagement of both authors in the activities of the movement. Hence, it is necessary to use an auto-ethnography as a specific research perspective.
The guidelines and principles for planning and design of road restraint systems
- Marcin Budzyński
- Marcin Antoniuk
2017 Pełny tekst MATEC Web of Conferences
The project RID 3A Road Safety Equipment (RoSE) implemented by the Gdansk University of Technology within the RID programme, aims to conduct a comprehensive study and analyses of different vehicle containment systems (PN-EN 1317) and types of support structures (PN-EN 12767) and their performance. Within the project an analysis will be conducted of available research reports and domestic and foreign experiences looking at road restraint systems and support structures applications. The paper will present a comparison of the guidelines and principles for the design and application of road restraint systems. Similarities and differences in the approach to different solutions will also be discussed. The above a nalyses will form the basis for the development of tools for selecting and applying road restraint systems in Poland.
The High Quality Business School Academic Teacher of the 21st Century – Polish Students’ Perspective
- Małgorzata Wiśniewska
- Piotr Grudowski
2017 Journal of Economics and Management Research
The literature shows that the success and competence of future managers depend on the quality of their academic teachers. Moreover high quality study requires high quality lecturing/teaching that creates an environment in which deep learning outcomes are made possible for students. The aim was to identify the characteristics of the academic teacher working at business schools, according to the expectations of Polish students from a 21st century perspective. A qualitative survey design was used in the form of a letter questionnaire. 144 second-year bachelor students of Gdańsk University from the Faculty of Management were asked to list a maximum of five, most preferred characteristics, and to comment their answers. Finally, 109 students participated in the study, and 471 characteristics were proposed, analysed and put into five categories: tangibles (T), reliability (Rel), responsiveness (Res), assurance (A) and empathy (E). Content analysis and Pareto-Lorenzo analysis was used and the most preferable characteristics were identified. Conclusions, proposals and recommendations were presented. The academic teacher has to be well prepared and teach in an interesting, innovative way with a use of modern techniques and methods. Very important is to apply not only the lecture-style methods, but also on-the job teaching, project-based teaching, team work-based teaching, action teaching, experiential teaching, small groups teaching, case studies, simulations, e-teaching, and even volunteering teaching. Not without the significance are coaching and mentoring and the features referring to the style of teaching, like charisma, creativity, passion, and engagement, which characterise good managers and business leaders.
The Hopf type theorem for equivariant gradient local maps
- Piotr Bartłomiejczyk
- Piotr Nowak-Przygodzki
2017 Pełny tekst Journal of Fixed Point Theory and Applications
We construct a degree-type otopy invariant for equivariant gradient local maps in the case of a real finite-dimensional orthogonal representation of a compact Lie group. We prove that the invariant establishes a bijection between the set of equivariant gradient otopy classes and the direct sum of countably many copies of Z.
The Housing Pattern and Entrepreneurship in Polish Suburban Landscape
- Justyna Martyniuk-Pęczek
- Grzegorz Peczek
- Olga Martyniuk
2017 Pełny tekst IOP Conference Series: Materials Science and Engineering
Abstract. Housing stimulates the development of SMEs (small and medium enterprises) in the suburbs. The multidisciplinary research in fields of urban planning and economics, carried out by the Authors, confirms this trend. The purpose of this paper is to present the multidisciplinary results of the research on the determinants of SME localization in the suburban areas of Gdansk, Gdynia and Sopot (the Metropolitan Area Gdansk–Gdynia-Sopot – MAGGS). Many of researchers attach great significance to the term of urban sprawl. Most authors agree that this phenomenon is multidimensional. It also varies in the global perspective. The conducted research showed that urban sprawl in Poland had a positive impact on the development of entrepreneurship, leading to a situation when the SME location quotient (LQ) in some suburban areas is higher, in comparison to the core city itself. The communities characterized by an LQ significantly higher than in the core city have been identified by Authors as ‘entrepreneurship nests’. To identify the research problem, a two-pronged research in the fields of urban and architectural design as well as economics was adopted. The charter of suburban landscape was determined by site analysis and through a study of the architectural form. The results confirmed that more than 80% of the parcels, which encompass economic activity, also exhibit a residential function. Our study confirms that urban sprawl, with its characteristic housing patterns, stimulates business activity in the suburbs. According to our results, this phenomenon is not only determined by financial factors, but also results from social and spatial reasons.
The ILs-assisted electrochemical synthesis of TiO2 nanotubes: The effect of ionic liquids on morphology and photoactivity
- Paweł Mazierski
- Justyna Łuczak
- Wojciech Lisowski
- Michał Jerzy Winiarski
- Tomasz Klimczuk
- A. Zaleska-Medynska
2017 Pełny tekst APPLIED CATALYSIS B-ENVIRONMENTAL
Facile and environmentally benign one-step titanium anodization method for TiO2 nanotubes (NTs) formation in a presence of ionic liquids (ILs) was proposed. Influence of the IL structure and its content in ethylene glycol electrolyte on morphology, surface properties and photoactivity of the TiO2 NTs was investigated. Possible interactions between IL and TiO2 NTs as well as the mechanism of NTs formation during anodic oxidation process were proposed. The outer diameter, wall thickness, and length of the IL-NTs were found to be proportionally related with increasing length of the hydrocarbon chain in the imidazolium cation of the IL (from 2 to 8), IL content, anodization potential and water content up to 10 vol.%. Moreover, for the first time, the effect of the IL’s structure on the UV–vis and Vis light-induced photoactivity of the IL-TiO2 NTs was presented, and the active species (•OH and O2 •− radicals) involved in the photocatalytic reaction of phenol degradation were determined. The sample that exhibited the highest photoactivity under Vis irradiation (0.63 mol dm−3 min−1) and greatest amounts of generated •OH was TiO2 NTs prepared at anodization potential 90V in the electrolyte containing 0.1 mol of 1- octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4] (represented by F− content) and 10 vol.% of water. Phenol degradation rate remained at level about 1.50 and 0.42 mol dm−3 min−1 after 60 min of UV–vis and Vis irradiation after four cycles in the presence of [OMIM][BF4] and thus obtained IL-NTs exhibited photostability. The reaction proceeds under mild reaction conditions, is step economical and provides one-dimensional nanostructures that meet the specifications for use in diverse photocatalytic applications.
The imidazoacridinone C-1311 induces p53-dependent senescence or p53-independent apoptosis and sensitizes cancer cells to radiation
- Anna Skwarska
- Shaliny Ramachandran
- Grzegorz Dobrynin
- Katarzyna B. Leszczynska
- Ester M. Hammond
2017 Pełny tekst Oncotarget
C-1311 is a small molecule, which has shown promise in a number of preclinical and clinical studies. However, the biological response to C-1311 exposure is complicated and has been reported to involve a number of cell fates. Here, we investigated the molecular signaling which determines the response to C-1311 in both cancer and non-cancer cell lines. For the first time we demonstrate that the tumor suppressor, p53 plays a key role in cell fate determination after C-1311 treatment. In the presence of wild-type p53, cells exposed to C-1311 entered senescence. In contrast, cells lines without functional p53 underwent mitotic catastrophe and apoptosis. C-1311 also induced autophagy in a non-p53-dependent manner. Cells in hypoxic conditions also responded to C-1311 in a p53-dependent manner, suggesting that our observations are physiologically relevant. Most importantly, we show that C-1311 can be effectively combined with radiation to improve the radiosensitivity of a panel of cancer cell lines. Together, our data suggest that C-1311 warrants further clinical testing in combination with radiotherapy for the treatment of solid tumors.
The Impact of ICTs on Women’s Economic Empowerment
- Dagmara Nikulin
2017
It is widely argued that ICTs enable the inclusion of low-skilled and traditionally marginalized groups, such as women, people with disabilities, and workers at the base of the pyramid (BoP), in the labor market. In this paper, we investigate the determinants of female participation in the labor market in developing countries with a focus on the impact of the use of ICTs on female labor force participation. We conduct a panel study analysis for 60 developing countries in the time period 2000–2014. Our results confirm that there is rather a positive impact from the use of ICTs on female labor force participation in developing countries. Moreover, we show that gross national income (GNI) per capita, fertility rates, and income inequalities influence to some extent the level of women’s engagement in the labor market. Our results are robust against different control variables, as well as different ICT proxies.
The impact of the distribution network reconfiguration on active power losses: Selected issues of UPGRID project realization
- Radosław Rekowski
- Krzysztof Dobrzyński
- Zbigniew Lubośny
2017
The dynamic development of smart grids allows the use of remote controllable switches to change the configuration of the distribution network. The paper discusses the impact of the distribution system reconfiguration on active power losses, taking into account the typical daily load profiles. Based on modified IEEE 33-bus test distribution system the article presents the method of selection the appropriate sensitivity factor and the configuration of the MV network. The objective function is to minimize active power losses. The studies were performed using DIgSILENT Powerfactory software for two variants of the daily load curve and for different values of the sensitivity coefficient. The calculation results indicate, that adequate (optimal) configuration of MV distribution network, ensures reduction of active power losses.