2014 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2014

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The Impact of urban Localizations on the Growth Possibilities for Small Firms
- Julita Wasilczuk
- Krzysztof Zięba
2014
The purpose of this study was to identify the differences in the profiles of firms and their owners in urban and non-urban locations and also to asses the impact of those differences on the possibilities of growth for firms from both types of locations. Findings: urban entrepreneurs are better educated, more experienced and more positively motivated. Their firms are more innovative, with more qualified employeesadn better access to entrepreneurial infra-structure. However, they are not growing better than non -urban ones. This is a powerful suggestions, meaning that all possible benefits coming from the urban environment may be balanced out by the accompanying disadvantages. Research limitations/implications: The research sample was limited only to the Pomeranian Region. Some non-urban firms were located in small towns, which makes them somewhat similar to urban firms. The research should be continued using a more polarised sample, in which differences between urban and non-urban firms could be more significant. Originality/value: The research sheds some light on the influence of urban and non-urban location on growth possibilities for SMEs, which remains an underresearched topic, especially in Poland.
The Implementation of the Taxonomic Spatial Measure of Development in the Analysis of Convergence in the Standard of Living
- Marta Kuc-Czarnecka
2014 Pełny tekst Acta Universitatis Lodziensis Folia Oeconomica
The main goal of this paper is to analyse the existence of the social convergence in the European Union between 19952012. The social convergence refers to a reduction in the dispersion of the standard of living across countries. A taxonomic spatial measure of development was used as the standard of living approximation. The use of the new approach proposed by E. Antczak allowed for an explanation of the disparities in the analysed phenomenon by taking into account the immeasurable spatial factor. A variety of techniques were used to test for convergence. The existence of sigma, beta and gamma convergence was tested for the global aggregated measure of the standard of living and, furthermore, for 10 groups of factors affecting this phenomenon.
The importance of a place in a small or medium - Sized Town.- Vol. 2
- Monika Trojanowska
2014
Public space is a matter of concern for international humanitarian organisations. The paper describes the initiative of UNHabitat organisation for the creation of Charter of Public Space and the draft of this document. Next the definition of “place” is provided and the definitions of social capital and the bond between social capital and place attachment are presented. The actions proposed nowadays to create places are described. The two approaches – first: lighter, quicker, cheaper proposed by PPS - Project for Public Spaces organisation and the second one: costly investments undertaken by many municipalities. The need for plants in public space is underlined. Final conclusions for small and middle towns are proposed at the end.
The influence of accumulation area and the length of pedestrian route on functioning of roundabouts with traffic signals
- Lucyna Gumińska
- Wojciech Kustra
2014 Transportation Research Procedia
traffic volumes. This kind of intersection is commonly used in the centres of Polish cities on multilane roads and fairly common in the case of tram lines running through a central island. The increase of traffic flow volumes on left turn and U-turn has made this type of roundabout difficult to operate. Small storage areas around central islands are critical places that significantly influence the capacity of this kind of intersection. The use of multiphase traffic signals causes major lengthening of crossing time for pedestrians which results in pedestrian delays at this kind of intersection. During the conducted analyses, microscopic models carried out in Transyt program, were used. They enabled the reconstruction of the traffic conditions and a few other important issues while assessing their capacity.
The influence of applying supplementary web plates on structural joint moment resistance and rotational stiffness
- Elżbieta Urbańska-Galewska
- Patryk Deniziak
2014 Pełny tekst Structure and Environment
Continual trend to simplify structural elements and find less time-consuming solutions on construction site as well as inevitable increase in labour costs determine for instance elimination of those technological steps that are difficult to automation. Welding additional reinforcements and web stiffeners is a great example of such a step. The method presented in EN 1993-1-8 [8] is a result of long-term studies focused on calculating the moment resistance and stiffness of joints without transverse web stiffeners. Design calculations shown in this paper are based on resistance and stiffness growth analysis applying supplementary web plates. Authors consider validity of this solution due to construction effort and building durability remembering about minimization of the costs.
The influence of core material on strength properties of hybrid sandwich panels
- Janusz Kozak
- Karol Niklas
2014
Along with high prices of fuels and more restrictive safety and environmental regulations (including environment protection) increased interest in sandwich structures is being observed. One of the solution having growing application potential is steel sandwich panel. The construction consist of very thin steel plates (about 2mm) and stiffeners between them. The main advantage of using such solution is very high strength to weight ratio. Additionally strength properties can be modified by using filling material inside the panel. As for now only panels filled with balsa and PVC have been tested. In spite of positive results of the tests and significantly better properties of panels with filling commercial usage of those composite panels is restricted due to high price. One of the most suitable material for a core of steel sandwich panel construction can be lightweight concrete. Special type of concrete was designed and used in this application being a compromise between strength properties and costs. The article focuses on experimental testing of hybrid (steel-concrete) panel construction. Strength tests were performed on the real scale construction with and without filling material. The influence of core material on strength properties of hybrid steel sandwich panels are being presented.
The influence of drying parameters on wood properties
- Jacek Barański
- Maciej Wierzbowski
2014
Results of influence of gas-steam mixture drying process on wood mechanical properties are presented. Wood species, namely pine (Pinus sylvestris L.) and beech (Fagus silvatica L.) from the northern part of Pomerania region in Poland, were subject of steam kiln-drying process in a laboratory kiln specially arranged for that reason.
The influence of drying parameters on wood properties
- Jacek Barański
- Daniel Chuchała
- Kazimierz Orłowski
- Tomasz Muziński
2014 Annals of WULS, Forestry and Wood Technology
The influence of drying conditions on wood properties is presented. The classical approach was used to determine energetic effects (cutting forces and cutting power) of wood sawing process on the basis of the wood specific cutting resistance, material constant. Before mashining wood material (soft and hard) was dryied at various conditions using air at 25oC, air-steam meaxture at 80oC and steam at 110oC.
THE INFLUENCE OF POLYMER STRIPS IN REDUCTION OF A STEEL GRANDSTAND VIBRATIONS
- Natalia Lasowicz
- Robert Jankowski
2014
Grandstands are types of structures commonly used during sport events or music concerts. Dynamic loads generated by crowd movement may have significant influence on human perception as well as may lead to the destruction of a structure. Lighter and more slender structural steel members are more easily excitable by spectators. If the synchronized movement is tuned with the natural frequency of the affected part of the structure, resonance might occur. A large number of accidents involving the collapse of temporary grandstands, during different types of events, has been observed in the past. More than 100 people were injured after a seating section gave way during a car race in Brazil in 2010. The collapse of a grandstand in Corsica in 1992 hurt thousands of people and resulted in several fatalities. Dynamic loads are often found to be the most important ones at the design stage of civil engineering structures. Safety and serviceability of these structures may need to be checked. In this paper, an idea of using polymer dampers, in order to reduce steel grandstand vibrations under dynamic loads, is proposed. The polymer mass is a specially designed flexible two-component grout, which is based on polyurethane resin. It has been proven that this kind of material has also additional damping properties [6]. A numerical analysis of a temporary steel grandstand has been conducted and dynamic parameters have been estimated. Four different models have been considered. Two of them describe a standard steel temporary structure (empty and occupied). In the second two models, polymer dampers (in the form of strips) have been added as a proposed method of reduction of structural vibrations. Numerical analysis has been conducted for all cases and behaviour of a steel grandstand under dynamic crowd load has been determined.
The influence of pre- and postharvest treatments on selected biological and epigenetic activities of Brassica sprouts
- Dominik Kołodziejski
- Joanna Cyprys
- Milena Groszewska
- Anna Piekarska
- Agnieszka Bartoszek-Pączkowska
2014 EUROPEAN JOURNAL OF CANCER
Introduction The Brassica vegetables are rich in glucosinolates (GLs), which are enzymatically hydrolysed to bioactive isothiocynates (ITC) and indoles, regarded as the most promising chemopreventing agents. However, in the majority of brassica sprouts the GL conversion into these beneficial derivatives occurs at the level of about 1 %, while in cabbage leaves exceeds 70%. Since sprouts represent plant material, which is frequently used for production of dietary supplements and functional foods, it is important to recognize their biological activity in the context of chemical composition. Materials and Method Sprouts were grown in the phytotrone without and with selenium addition (preharvest treatment). After harvest, a portion of sprouts was exposed on physico-chemical treatment (postharvest treatment). Biological evaluation was carried out with the aid of HT29 cell line for water extracts from lyophilized sprouts. For concentration causing less then 50% cytotoxicity, the ability to induce cytoprotective enzymes, i.e. glutathione-S-transferases (GST) and NAD(P)H:quinone oxidoreductase (NQO1), was examined. Furthermore, the influence of extracts on HDAC (class I and II) and sirtuin activity, which are a part of epigenetic regulatory mechanisms, was determined by plate-format tests offered by Promega company.
THE INFLUENCE OF QUESTION SET ON STUDENT QUIZ RESULTS
- Artur Opaliński
2014 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
The advent of e-Learning tools allowing for automated online test grading will probably increase the frequency of using tests in technical education. The same tools may provide for measures of test question quality. By purposely crafting question sets, test grading may serve different goals. The paper contains examples and test study with score histograms.
The influence of screw configuration and screw speed of co-rotating twin screw extruder on the properties of products obtained by thermomechanical reclaiming of ground tire rubber
- Krzysztof Formela
- Magdalena Formela
- Józef Haponiuk
2014 Pełny tekst Polimery
The results of our investigations on the process of continuous thermomechanical reclaiming of ground tire rubber (GTR) carried out using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear forces. The influence of screw configuration and screw speed on breaking of chemical crosslink bonds contained in ground tire rubber are characterized by extrusion parameters, the acetone extract content, the content of the soluble fraction, the degree of reclaiming and the crosslink density of the obtained products. The effect of a secondary curing on the mechanical properties (tensile strength, elongation at break, hardness, resilience and abrasion resistance) of the obtained materialswas also determined. It has been established that the thermomechanical reclaiming process depends on shear forces acting on the rubber particles, while the degree of reclaiming increase with the increasing screw speed. Achange in screw configuration significantly affects the processing of ground tire rubber during reclaiming process. For example, preliminary pulverization of the fine rubber particles in the first zone of barrel facilitates further processing in the twin screw extruder, which is beneficial in order to decrease the screw torque and the energy consumption in the production of reclaimed rubber. Thermogravimetry analysis
The influence of selenium addition during germination of Brassica seeds on health-promoting potential of sprouts
- Anna Piekarska
- Dominik Kołodziejski
- Tadeusz Pilipczuk
- Małgorzata Bodnar
- Piotr Konieczka
- Barbara Kusznierewicz
- F.s. Hanschen
- M. Schreiner
- Joanna Cyprys
- Milena Groszewska
- Jacek Namieśnik
- Agnieszka Bartoszek-Pączkowska
2014 Pełny tekst INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION
The correlation among selenium uptake, the content of bioactive compounds in sprouts, and biological activities triggered in cultured human cells by sprout extracts was investigated. Seeds of Brassica crops and rye were treated with SeO2 water solution. The selenium levels in sprouts increased from 1.0-4.1 to 53.3-382 μg/g dw with no influence on plant physiology according to the indices used. Neither the composition of glucosinolates (GL) in Brassica sprouts nor the myrosinase activity nor the composition of GL breakdown lipophilic products were significantly affected. In all Brassica sprouts, conversion to health-promoting isothiocyanates (ITC) and indoles corresponded to only 1% of total GLs. Low ITC concentration may explain observed lack of induction of glutathione S-transferases (GST) and quinone oxidoreductase (NQO) detoxifying enzymes in HT29 cells exposed to sprout extracts. The insignificant impact on cell growth and genome function suggests that Brassica sprouts may be safe vehicle of selenium to combat its dietary deficiency.
The inhibition effect of mad Honey on corrosion of 2007-type aluminium alloy in 3.5% NaCl solution
- Husnu Gerengi
- Haydar Goksu
- Paweł Ślepski
2014 Materials Research-Ibero-american Journal of Materials
The inhibition effect of mad honey on corrosion of 2007-type aluminium alloy in 3.5% NaCl solution was investigated by Tafel extrapolarisation (TP), electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS). All the studied parameters exhibited good anti-corrosive properties against corrosion of 2007-type aluminium alloy in the test solution; the corrosion rates decreased with the increase of the mad honey concentration. The surface morphology of the alloy was examined under scanning electron microscopy (SEM) in the absence and presence of the inhibitor. The inhibitory adsorption processes of mad honey on the 2007-type aluminium alloy surfaces conformed to the Langmuir adsorption isotherm.
The initial selection of parameters for dynamic brake for car engine test dynamometer
- Zbigniew Kneba
- Jacek Kropiwnicki
2014 Key Engineering Materials
The article presents an analysis of the car engine loads. The aim of the analysis was to determine the parameters of the brake / electric motor on an engine test bad. Analysis of loads on the driving tests concerned on chassis dynamo to simulate them on an engine dynamometer. To check the range of dynamometer shaft angular acceleration inertial mass of a car was reduced on the crankshaft axis. The calculations of maximum shaft acceleration were performed. Also the whole car acceleration when pulling away from the place was calculated. Calculations were verified by experiment on road. They both gave a good agreement.
THE INTERNATIONAL COMPETITIVENESS OF EUROPEAN UNION COUNTRIES AND STRATEGIES FOR ITS ENHANCEMENT: A TAXONOMIC ANALYSIS
- Magdalena Olczyk
2014 Pełny tekst Metody Ilościowe w Badaniach Ekonomicznych
The aim of this article is to identify clusters of countries with similar levels of competitiveness among the EU-27 countries and to identify for each of the 27 EU countries the path to growth in competitiveness. The taxonomic cluster analysis conducted confirms the hypothesis that the European Union is an area with a high differentiation in terms of levels of competitiveness. The analysis shows that the strategy to increase competitiveness should be significantly different for each EU country. It is suggested that in order to increase its international competitiveness each EU country should follow the pattern of the country which stands above it in terms of competitiveness ranking, but at the same time is most similar
The investigation of polyester composites filled by modified bentonite
- Mariola Jastrzębska
- Helena Janik
- Dominik Paukszta
2014 Pełny tekst Polimery
Praca dotyczy zagospodarowania odpadów poliestrowo-szklanych przez wytworzenie kompozytów z ich użyciem oraz żywicy poliestrowej, mączki dolomitowej i nanonapełniacza. Wykazano, ze dodatek 2% nanonapełniacza do do kompozytów poliestrowych zawierających 15% masowych odpadów pozwala na uzyskanie materiału wykazującego korzystne właściwości wytrzymałościowe. Proponowany sposób modyfikacji kompozytów poliestrowych jest nowym rozwiązaniem i może przyczynić się do zagospodarowania części odpadów poliestrowo-szklanych.
The Large Customer Reactive Power Control Possibilities
- Robert Małkowski
- Zbigniew Szczerba
2014 Pełny tekst Acta Energetica
n this paper the authors wish to draw attention to the rationale for, and the possibility of, the use of local reactive power sources by the Transmission Node Master Controller (TNMC). Large Customers (LC) are one of the possible reactive power sources. The paper presents the issues related to the need for coordination between the control systems installed in the LC network, and coordination between control systems of the LC as well as master control systems in the network.
The low energy house using an air solar collector - a case study
- Jolanta Fieducik
- Jan Godlewski
2014 Pełny tekst Czasopismo Techniczne
Celem tego artykułu jest przedstawienie możliwości ogrzewania i chłodzenia domu jednorodzinnego przy wykorzystaniu słonecznych kolektorów powietrznych. W analizie uwzględniono dom energooszczędny, którego wskaźnik sezonowego zapotrzebowania na ciepło wynosi 40kWh/m2/a. Do obliczeń przyjęto kolektory powietrzne dostępne na rynku o powierzchni 60m2 i wydajności wynoszącej 70%. W analizowanym budynku występuje prawie pełne pokrycie potrzeb na energię grzewczą w ciągu roku z powietrznych kolektorów słonecznych, oprócz niewielkich braków w tym względzie występujących w grudniu i styczniu. Wspomniane w tym przypadku pewne braki ciepła w końcu i na początku roku można uzupełnić z innych alternatywnych źródeł ciepła.
The method of analysis of damage reinforced concrete beams using terrestial laser scanning
- Krystyna Nagrodzka-Godycka
- Jakub Szulwic
- Patryk Ziółkowski
2014
The authors present an analysis of the possibility to assess deformations and mechanisms of destructing bent reinforced concrete beams using the terrestrial laser scanning. As part of the experiments carried out at the Regional Laboratory of Construction of the Concrete Structures Division of the Civil and Environmental Engineering Faculty at Gdansk University of Technology, the reinforced concrete beams were subjected to destruction by bending and by shear. The process of press impact on the reinforced concrete beam was recorded using a terrestrial laser scanner within the frames of cooperation between the university and the manufacturer of the scanner. Development of scanning effects was performed using Leica Cyclone software and MeshLab (GNU General Public License). In order to verify the results, the independent recording of beam deflection was carried out with the use of extensometer and the recording with non-meter synchronous digital cameras was carried out and photos from these cameras were subjected to photogrammetric processing. However, the principal subject of this paper is to show the usefulness of laser scanning for the analysis of reinforced concrete beams damages and authors of this paper focused on this subject. The selection of reinforced concrete beam in this case was a conscious action, aimed at preparing the assessment of the suitability of laser scanning in reference to the element well described in the literature and known in the field of mathematical description of its destruction process. In the description of the experiment there are six stages of measurement mentioned for the reinforced concrete beam: from the zero condition (no force), through intermediate conditions up to the stage of destruction. Scanning was performed from one stable measurement station to avoid in processing the effect of correlation errors (matching and linking) of ScanWorld. Analysis of the materials from laser scanning allowed to assess the geometry of element subjected to destruction with an accuracy not worse than 1 mm. For this purpose, the method of spheres translation was developed and in its characteristic groups of points from scanning the spheres were described. Spheres centers grew to be geometrical element to be assessed on scans in subsequent measurement epochs.