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  • Earthquake-Induced Structural Pounding
    • Robert Jankowski
    • Sayed Mahmoud
    2015 GeoPlanet: Earth and Planetary Sciences

    Earthquake-induced structural pounding between insufficiently separated build-ings, or bridge segments, has been repeatedly observed during ground motions. The reports after earthquakes indicate that it may lead to some local damage in the case of moderate seismic events or may result in considerable destruction or even collapse of colliding structures during severe ground motions. Pounding in build-ings is usually caused by the differences in dynamic properties of structures which make them vibrate out-of-phase under seismic excitation. On the other hand, in the case of longer bridge structures, spatial seismic effects related to the propagation of seismic wave are more often responsible for collisions between superstructure segments during earthquakes. The aim of the book is to analyse different ap-proaches of modelling the earthquake-induced structural pounding as well as to the show the results of the studies on collisions between buildings and between bridge segments during ground motions. The aspects related to mitigation of pounding effects as well as the design of structures prone to pounding are also dis-cussed.

  • EASY ACCESS TOOL FOR SMALL INTERFERING RNA (siRNA) DATA
    • Monikaben Padariya
    • Umesh Kalathiya
    2015

    For many decades it was an accepted dogma of molecular genetics that the expression of genes is a “one-way-road” leading only in one direction from DNA to RNA to proteins. Recent discoveries in modern molecular genetics have challenged this dogma showing that specific RNA molecules play a central role in controlling the activity of genes by changing the structure of DNA sequences, targeting other RNAs for degradation or blocking the translation of messenger RNAs into proteins. Small interfering RNA (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded RNA molecules, 20-25 nucleotides in length, that play a variety of roles in biology. Most notably, siRNA is involved in the RNA interference (RNAi) pathway, where it interferes with the expression of a specific gene. In order to organize important data of siRNA, easy access tool is developed using WAMP server and PHP programming. In this tool, four different organism (mouse, rat, hepatitis B virus and hepatitis C virus) and their related siRNA data are stored which include information about gene and sequence of siRNA. All these details have cross-linked with other databases. This tool gives provision to researchers to submit newly discovered sequences with experimental references.

  • ECONOMIC GROWTH AND FEMALE LABOR FORCE PARTICIPATION – VERIFYING THE U-FEMINIZATION HYPOTHESIS. NEW EVIDENCE FOR 162 COUNTRIES OVER THE PERIOD 1990-2012.
    • Ewa Lechman
    • Harleen Kaur
    2015 Pełny tekst Economics & Sociology

    The paper contributes by providing new insights into relationship between female labor force and economic growth in 162 world countries over the period 1990-2012. It is anticipated uncovering U-shaped relationship between female labor force participation and economic growth. The analysis is run in two different perspectives – first the relationship is examined for sample encompassing 162 countries; and second – the evidence is disaggregated and the relationship is re-examined in four income-groups (low-income, lower-middle-income, upper-middle-income and high-income). To this aims data on female labor force participation and per capita income are extracted from the World Development Indicators 2013 database, and the relationship by deploying panel data analysis assuming non-linearity between variables is examined. The main findings support the hypothesis on U-shaped relationship between female labor force participation and economic growth, however high cross-country variability on the field is reported. Moreover, only in case of low-income countries, the U-shaped feminization hypothesis was not positively verified.

  • Economic situation perception and the growth plans of microenterprises, case of Poland
    • Julita Wasilczuk
    2015

    Numerous scientific studies provide information on the impact of the environment on the launch, operation and growth of businesses. Reflections on the environment can result from two perspectives: the objective and the subjective one. The first relates to the economic analysis and/or sociological research, whereas the second relies on the perception of the environment by the interested parties themselves. While analysing companies from the SME sector, the author usually deals with businesses whose owners are not formally trained in management. Their abilities come primarily from experience and occasional courses. As a result, such entrepreneurs’ manner of environment evaluation — in particular related to the economic situation — is often based on intuition. However, the intuition is shaped to some extent by the opinions of others, either oral or written. In Poland those opinions depend to a large extent on the political option represented by the person uttering them, and are largely spread by different daily and weekly newspapers. Therefore the owners decide to take some actions or refrain from them, following their subjective perceptions of the environment. The concept of entrepreneurs' perception forms a part of broader entrepreneurship approach known as Entrepreneurial Cognition (EC) (Mitchell, et al., 2007). At first glance, it may seem that relying on intuition and subjective perception should not take place, as decisions taken in such a way could be disadvantageous for the entrepreneur. On the other hand, “positive ignorance” or misunderstanding negative environmental phenomena could, paradoxically, bring success. Entrepreneurial behaviour (flexibility, quick response, strong motivation) (Baker, Miner, & Eesley, 2003) can lead to overcoming real threats, previously unrecognized by the entrepreneur. The objective of this research is to find the relation between subjective perception of environment and the growth plans of small enterprises in a post-communist country during the slowing down of economy.

  • Economic Vitality of Polish Suburbs
    • Justyna Martyniuk-Pęczek
    • Olga Martyniuk
    • Grzegorz Pęczek
    2015

    For over 25 years, Poland has been undergoing major political, social and economic transformations. The country's system changed from a planned economy to a free-market, neo-liberal one. The effects of these changes are visible on several levels, including the field of urban planning, where they manifested themselves as the birth of the suburbanization process. In the field of economics, it could be noticed that since 1989, the SME sector has been awakening very dynamically. Correlation of the parallel development of these two phenomena has led the authors to pose a question about the emerging potential links between the occurring processes i.e. - the process of the urban sprawl and the development of the SME sector. In this context, a thesis was established about emergence of the so-called "entrepreneurship nests", made up of a dispersed urban tissue with residential functions intermixed and high intensification of economic entrepreneurship, in the Polish suburb areas. To identify the research problem, a two-pronged research in the fields of urban planning and economic research was adopted. The Gdansk Metropolitan Area (GMA) was the subject of research. Municipalities with the highest suburbanization rate were established on the basis of the migration balance. Subsequently, business entities in those areas were identified with their business activity measured by the location quotient (LQ). The results of the classification of the units within GMA (cities, town village communities, village communities) according to the migration rate and the construction activity index indicated 7 communities with the highest intensity of the suburbanization process. Our analysis of LQ in all units within GMA (cities, town village community, village communities) and its core cities allowed identification of the communities with the highest SME activity. Additionally, based on statistical data of selected suburban areas, 2 municipalities (Chwaszczyno, Straszyn) with the highest entrepreneur potential were found, which we refer to as the nests of entrepreneurship. Our study confirms that communes characterized by the highest intensity of the suburbanization processes present higher business activity than other communes. However, this is just preliminary study, which offers incomplete explanation of the suburbanization process in a metropolitan area in Poland and will be further developed, using the CATI method, in additional studies.

  • Edward Kajdański. Z Harbinu do Gdańska - śladami wybitnego absolwenta.
    • Adam Barylski
    2015 Pismo PG

    Przedstawiono niezwykłe życie i twórczość absolwenta Wydziału Mechanicznego z roku 1960, dyplomaty, pisarza i dziennikarza, wybitnego znawcy historii, kultury i medycyny Dalekiego Wschodu, wpisane w losy harbińskiej Polonii.

  • EFEKTYWNA TECHNIKA POSZUKIWANIA MIEJSC ZEROWYCH FUNKCJI ZESPOLONYCH WYSTĘPUJĄCYCH W ZAGADNIENIACH PROPAGACYJNYCH
    • Piotr Kowalczyk
    2015 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Artykuł dotyczy zastosowania nowatorskiego algorytmu poszukiwania miejsc zerowych (na płaszczyźnie zespolonej) do badania własności propagacyjnych prowadnic mikrofalowych. Problemy tego typu występują nie tylko przy analizie struktur stratnych, ale również w badaniu zjawisk związanych z wypromieniowaniem (rodzaje wycie-kające i zespolone). Proponowany algorytm jest prosty w implementacji, a jednocześnie „odporny” na osobliwości i cięcia płaszczyzny zespolonej, często występujące w tego typu zagadnieniach.

  • EFEKTYWNOŚĆ STOSOWANIA ZDERZAKÓW STYROPIANOWYCH POMIĘDZY ZDERZAJĄCYMI SIĘ KONSTRUKCJAMI STALOWYMI
    • Barbara Sołtysik
    2015 Zeszyty Naukowe Politechniki Gdańskiej. Inżynieria Lądowa i Wodna

    Podczas wstrząsów sejsmicznych o różnym natężeniu, wielokrotnie obserwowano zjawisko zde-rzania się konstrukcji ze sobą sąsiadujących, co mogło prowadzić nawet do jej całkowitego zniszczenia. Na podstawie obserwacji, badań numeryczny i eksperymentalnych stwierdzono, że przyczyną kolizji jest niedostateczna przerwa pomiędzy konstrukcjami. Ponadto czynnikami, które również mogą doprowadzić do zderzeń są różnice w masach lub sztywnościach budynków, które wpływają na prze-sunięte w fazie drgania, doprowadzając do kolizji. Celem niniejszej pracy jest przedstawienie wyników badań eksperymentalnych trzech sąsiadują-cych ze sobą modeli konstrukcji stalowych o różnych charakterystykach dynamicznych, które na skutek obciążeń sejsmicznych zderzają się ze sobą. Ponadto przeanalizowano wpływ zastosowanych zderzaków styropianowych o grubości 10 mm, umieszczonych w przerwie dylatacyjnej, na odpowiedź poszczególnych konstrukcji. Przeprowadzono wielokrotne pomiary dla różnych wartości dylatacji oraz dwóch wariantów obciążenia modeli, jednak w pracy zostały przedstawione wyniki dla przerwy dylatacyjnej =30 mm oraz Wariantu 2 obciążenia wież. Wyniki badań eksperymentalnych wskazują na istotny wpływ zderzeń pomiędzy sąsiadującymi konstrukcjami na ich odpowiedź, prowadząc zarówno do jej zmniejszenia, jak i zwiększenia. Ponadto zastosowanie zderzaków styropianowych, doprowadziło do zmniejszenia przerwy dylatacyjnej, czego efektem była zmiana ekstremalnych wartości przyspieszeń poszczególnych wież.

  • Efektywność usuwania wybranych organicznych związków azotu w komunalnych oczyszczalniach ścieków
    • Krzysztof Czerwionka
    2015 Pełny tekst Inżynieria Morska i Geotechnika

    Celem badań było określenie przemian jakim podlegają wybrane związki organiczne zawarte w ściekach oczyszczanych biologiczne metodą osadu czynnego. Zbadano stężenia 21 wybranych aminokwasów, mocznika i EDTA w ściekach dopływających i odpływających z bioreaktorów. W analizie uwzględniono wpływ odcieków z odwadniania osadów. Stwierdzono bardzo wysokie efektywności usuwania mocznika (ponad 97%) oraz wysokie dla EDTA (80-90%) i aminokwasów (82-88%).

  • Effect of bulk solid on strength of cylindrical corrugated silos during filling.
    • Natalia Kuczyńska
    • Michał Wójcik
    • Andrzej Tejchman-Konarzewski
    2015 JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH

    W artykule przedstawiono wyniki MES dla metalowych silosów z blachy falistej o kształcie cylindrycznym. Obliczenia wykonano podczas stanu napełnienia silosów z uwzględnieniem materiału sypkiego. Materiały sypki został opisany hipoplastycznym modelem konstytutywnym. W obliczeniach wzięto pod uwagę wstępne imperfekcje geometryczne. Wyniki porównano dla silosów pustych. Zaobserwowano pozytywny efekt obecności materiału sypkiego.

  • Effect of geometric imperfections on aluminium silo capacities
    • Jarosław Górski
    • Tomasz Mikulski
    • Magdalena Oziębło
    • Karol Winkelmann
    2015 STAHLBAU

    An aluminum silo with initial imperfections is analysed. Two types of imperfections are considered. The first one takes the form of local indentations in the shell; their size and range are adopted on the basis of the standard guidelines. The second type is a global imperfection described through the use of its eigenforms and by means of two-dimensional random fields. The calculations are limited to two cases of loading: negative pressure and wind. The choice of the loading has been suggested in Eurocodes. In the case of wind load, the probability distribution of its direction is taken into account.

  • Effect of ground tire rubber on structural, mechanical and thermal properties of flexible polyurethane foams
    • Łukasz Piszczyk
    • Aleksander Hejna
    • Krzysztof Formela
    • Magdalena Danowska
    • Michał Strankowski
    2015 Pełny tekst IRANIAN POLYMER JOURNAL

    Flexible polyurethane foams were modified with two kinds of ground tire rubber, untreated and thermo-mechanically reclaimed. A reclamation process was performed in auto-thermal conditions, which reduced the cost of the process and decreased the environmental impact of devulcanization (e.g., emission of gases). The reclamation process was carried out in a continuous manner using a co-rotating twin screw extruder. The foams were prepared by a single step method for the ratio of isocyanate groups to hydroxyl groups equals to one. The ground tire rubber particles were added to a polyol mixture. The impact of the rubber treatment on the properties of resulting polyurethane composites was determined by the analysis of static and dynamic mechanical properties and thermal properties. The incorporation of rubber particles into the polymer matrix caused significant changes in the cellular structure of polyurethane foam, which was confirmed by SEM images. Moreover, a higher content of ground tire rubber in the polyurethane/ground tire rubber foamed composites enhanced their cross-link density estimated from the swelling measurements. It was also confirmed by an increase of glass transition temperature measured by dynamic mechanical analysis and differential scanning calorimetry. Addition of ground tire rubber to polyurethane foams had very positive influence on their thermal stability measured by the temperature corresponding to the 2 % mass loss during degradation of material. Modification increased initial degradation temperature even by 14 °C compared to a reference sample.

  • Effect of kenaf fibre modification on morphology and mechanical properties of thermoplastic polyurethane materials
    • Janusz Datta
    • Patrycja Jutrzenka Trzebiatowska
    2015 Pełny tekst INDUSTRIAL CROPS AND PRODUCTS

    The presented study examined the morphology and mechanical properties of biocomposites obtained from kenaf natural fibre and thermoplastic polyurethane. Kenaf was modified using various methods, namely: acetylation, blocked isocyanate, maleic anhydride and permanganate treatment. Those methods and ways of carrying out of surface modifications were not studied before on kenaf/thermoplastic polyurethane composites. Different fibre loadings: 10% and 30% (by weight) were applied. The chemical treatments of fibres was confirmed by FTIR. The fibres surface and adhesion of the fibres to matrix was investigated using a scanning electron microscope (SEM). The modulus, tensile strength, elongation at break, hardness, resilience and water absorption were also determined; all results were compared with a untreated kenaf fibre composite. SEM investigations of fibres showed the differences of fibre surface after the chemical treatment. A good adhesion between the polymer matrix and fibres was observed for PU/PMn-KF 30 sample. DMA results indicated that the greatest values exhibited samples with fibre treated by acetylation and permanganate treatment. Increasing the amount of fillers in the polymer matrix leads to higher hardness values and water uptake. Tensile strength and resilience of composites decreased when a higher proportion of kenaf fibre was added. It was observed that the treated fibre composites showed improvement in tensile properties, hardness, resilience and lower water uptake for composites with 10% fibre loading.

  • Effect of Maximal Apnoea Easy-Going and Struggle Phases on Subarachnoid Width and Pial Artery Pulsation in Elite Breath-Hold Divers
    • Pawel Winklewski
    • Otto Barak
    • Dennis Madden
    • Agnieszka Gruszecka
    • Marcin Gruszecki
    • Wojciech Gumiński
    • Jacek Kot
    • Andrzej F. Frydrychowski
    • Ivan Drvis
    • Zeljko Dujic
    2015 Pełny tekst PLOS ONE

    Purpose: The aim of the study was to assess changes in subarachnoid space width (sas-TQ), the marker of intracranial pressure (ICP), pial artery pulsation (cc-TQ) and cardiac contribution to blood pressure (BP), cerebral blood flow velocity (CBFV) and cc-TQ oscillations throughout the maximal breath hold in elite apnoea divers. Non-invasive assessment of sas-TQ and cc-TQ became possible due to recently developed method based on infrared radiation, called near-infrared transillumination/backscattering sounding (NIR-T/BSS). Methods: The experimental group consisted of seven breath-hold divers (six men). During testing, each participant performed a single maximal end-inspiratory breath hold. Apnoea consisted of the easy-going and struggle phases (characterised by involuntary breathing movements (IBMs)). Heart rate (HR) was determined using a standard ECG. BP was assessed using the photoplethysmography method. SaO2 was monitored continuously with pulse oximetry. A pneumatic chest belt was used to register thoracic and abdominal movements. Cerebral blood flow velocity (CBFV) was estimated by a 2-MHz transcranial Doppler ultrasonic probe. sas-TQ and cc-TQ were measured using NIR-T/BSS. Wavelet transform analysis was performed to assess cardiac contribution to BP, CBFV and cc-TQ oscillations. Results: Mean BP and CBFV increased compared to baseline at the end of the easy phase and were further augmented by IBMs. cc-TQ increased compared to baseline at the end of the easy phase and remained stable during the IBMs. HR did not change significantly throughout the apnoea, although a trend toward a decrease during the easy phase and recovery during the IBMs was visible. Amplitudes of BP, CBFV and cc-TQ were augmented. sas-TQ and SaO2 decreased at the easy phase of apnoea and further decreased during the IBMs. Conclusions: Apnoea increases intracranial pressure and pial artery pulsation. Pial artery pulsation seems to be stabilised by the IBMs. Cardiac contribution to BP, CBFV and cc-TQ oscillations does not change throughout the apnoea.

  • Effect of mean grain diameter on vortices, force chains and local volume changes in granular shear zones
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    • Jan Kozicki
    • Danuta Leśniewska
    2015

    W artykule pokazano rozwój różnych zjawisk mikrostrukturalnych na poziomie ziarna materiału granulowanego podczas parcia pasywnego piasku na sztywną ściankę przemieszczającą się poziomo. Obliczenia wykonano stosując metodę DEM. Wyniki na poziomie globalnym porównano z wynikami MES. Szczególna uwagę zwrócono na rozwój wirów i łańcuchów sił miedzy ziarnami.

  • Effect of presence of lifting pocket on the THD performance of a large tilting-pad thrust bearing
    • Michel Fillon
    • Michał Wodtke
    • Michał Wasilczuk
    2015 Pełny tekst Journal of Friction and Wear

    Hydrostatic assistance is a commonly used method to improve limited load carrying ability of tiltingpad thrust bearings during transient states of operation of vertical shaft hydro-generators. Despite of special hydraulic equipment (as pumps, valves, etc.), it also requires manufacturing of special recesses/pockets at pad sliding surfaces, into which oil is injected under high pressure. It allows to lift the rotor before start-up of the machine and form a hydrostatic film between pads and collar. There is a quite wide variety of geometry of recesses (shape, depth, and size) met in practical large bearing applications. The presence of a hydrostatic pocket (usually located in the sliding surface above the pivot area, where thin film, high oil pressure and temperature are observed) affects bearing performance under hydrodynamic operation. In theoretical researches, there is an almost common practice not to include hydrostatic recess in thermohydrodynamic (THD) or thermoelastohydrodynamic (TEHD) analysis. This is probably due to the problems with obtaining solution for oil film geometry with pocket, the order of magnitude of the pocket depths being larger than gap thickness. In this paper, an attempt was taken to study the effect of lifting pocket on THD performance of a large tilting-pad thrust bearing of Itaipu power plant. Bearing performance was evaluated including recess shape for several cases of its depth. The results show that hydrostatic recess changes calculated bearing properties quite significantly, especially in vicinity of the pocket.

  • Effect of shallow traps on admittance spectra of the system carrying SCLC and on values of charge carrier mobility extracted from susceptance
    • Piotr Budzisz
    • Ryszard Signerski
    • Grażyna Jarosz
    2015 CHEMICAL PHYSICS

    The work concerns small-signal spectra of space-charge-limited current below threshold frequency (ft) of shallow traps. It is shown that below ft the small-signal concentration of trapped charge carriers is proportional to and in phase with small-signal concentration of free charge carriers, so there is no room for “slow shallow traps”. Conductance can be reduced by the traps, however no change in the range of real capacitance can be noticed. Applying the susceptance method for extraction of charge carrier mobility we get effective mobility which should be treated as mobility averaged over all charge carriers.

  • Effect of some organic solvent - water mixtures composion on precipitated calcium carbonate in carbonation process
    • Donata Konopacka-Łyskawa
    • Barbara Kościelska
    • Jakub Karczewski
    2015 JOURNAL OF CRYSTAL GROWTH

    Precipitated calcium carbonate particles were obtained during carbonation of calcium hydroxide slurry with carbon dioxide. Aqueous solutions of isopropyl alcohol, n-butanol and glycerol were used as solvents. Concentration of organic additives in the reactive mixture was from 0 to 20 % (vol.). Precipitation process were performed in a stirred tank reactor equipped with gas distributor. Multimodal courses of particles size distribution were determined for produced CaCO3 particles. Calcium carbonate as calcite was precipitated in all experiments. The mean Sauter diameter of CaCO3 particles decreased when the concentration of all used organic additives increased. The amount of small particle fraction in the product increased with the increasing concentration of organic solvents. Similar physical properties of used liquid phase resulted in the similar characteristics of obtained particles.

  • Effect of Some Sulphur Additives on The Degradation of 9Cr-1Mo Steel After Its 10 Years Service in The CCR Platforming Unit
    • Jan Dampc
    • Marek Szkodo
    2015 Solid State Phenomena

    The work shows the results of the tests of 9Cr-1Mo steel, which was for 10 years operated in the CCR platforming unit in Group Lotos SA in Gdańsk, and then in the laboratory was sulphidised during 166 h at a temperature of 600 °C. Sulphidation was performed in a mixture of H2-H2S gases at the vapour pressure of sulphur 4.1·10-14 atm, so the order of magnitude of vapour pressure was less than that of the dissociation pressure of FeS. Although sulphidising took place in conditions which preclude any iron sulphide formation, research results have demonstrated that after 166 hour exposure in reaction mixture in 9Cr-1Mo steel produces iron and chromium sulfides. Sulphide precipitates form under a layer of fine carbides, located directly on the surface of steel. Formation of scale sulphide here is most likely caused by the penetration of hydrogen sulphide through the porous layer of carbides that increases the pressure of hydrogen sulphide. Thus the vapour of sulphur in apertures and narrow passages occurs between the layer of carbides and the rest of oversaturated carbon layer top, until its pressure value is reached allowing the formation of sulphide scaling.

  • Effect of starch fillers on the dynamic mechanical properties of rubber biocomposite materials
    • Janusz Datta
    2015 Pełny tekst POLYMERS & POLYMER COMPOSITES

    In the paper the results of dynamic mechanical study of the biocomposites containing one of two types of (potato or corn) strach used as fillers in different amount were discussed. The composites were obtained from rubbery mixture containing natural rubber (NR) as a main component. Thermomechanical analyses (by DMA) showed that the used quantity of strach fillers only slightly influence on the glass transition temperature of vulcanizates.