2018 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2018

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Influence of Bitumen Type and Asphalt Mixture Composition on Low-Temperature Strength Properties According to Various Test Methods
- Marek Pszczoła
- Cezary Szydłowski
2018 Pełny tekst Materials
In regions with low-temperatures, action transverse cracks can appear in asphalt pavements as a result of thermal stresses that exceed the fracture strength of materials used in asphalt layers. To better understand thermal cracking phenomenon, strength properties of different asphalt mixtures were investigated. Four test methods were used to assess the influence of bitumen type and mixture composition on tensile strength properties of asphalt mixtures: tensile strength was measured using the thermal stress restrained specimen test (TSRST) and the uniaxial tension stress test (UTST), flexural strength was measured using the bending beam test (BBT), and fracture toughness was measured using the semi-circular bending test (SCB). The strength reserve behavior of tested asphalt mixtures was assessed as well. The influence of cooling rate on the strength reserve was investigated and correlations between results from different test methods were also analyzed and discussed. It was observed that the type of bitumen was a factor of crucial importance to low-temperature properties of the tested asphalt concretes. This conclusion was valid for all test methods that were used. It was also observed that the level of cooling rate influenced the strength reserve and, in consequence, resistance to low-temperature cracking. It was concluded that reasonably good correlations were observed between strength results for the UTST, BBT, and SCB test methods.
Influence of bitumen type on cracking resistance of asphalt mixtures used in pavement overlays
- Piotr Jaskuła
- Cezary Szydłowski
- Marcin Stienss
2018 Pełny tekst IOP Conference Series: Materials Science and Engineering
Cracking is one of the predominant distresses occurring in flexible pavements, especially in old pavements that were rehabilitated with an asphalt overlay. In such cases asphalt mixtures should be designed to ensure high resistance to reflective cracking because new asphalt layers are exposed to existing cracks of the old pavement. The nature of these cracks can be various (transverse, longitudinal as well as crazy cracking). One factor that minimizes this type of distress is the proper mix design process, which should involve selection of specific bitumen binder and mineral mix gradation. However, still there is no universally adopted laboratory test method that would allow to clearly assess resistance of asphalt mixtures to reflective cracking. This paper describes the usage of one of the devices developed to test asphalt mixtures in terms of such distress – Texas Overlay Tester. For this test, samples prepared in laboratory conditions (i.e. compacted with the use of Superpave Gyratory Compactor) as well as obtained in the field (by core drilling) can be used. The results are obtained not only quickly and easily, but also with sufficient repeatability. The described method characterizes both crack initiation and crack propagation properties of asphalt mixtures. In this work one type of mineral mixture was tested with 4 different types of bitumen (one neat bitumen, two ordinary polymer-modified and one polymer-modified with high polymer content). For selected cases extra additives (rubber and loose fibres) were also tested. In total, six asphalt mixtures were tested. A ranking of the used binders was created on the basis of the results in order to conclude which bitumen would ensure the best performance characteristics in terms of reflective cracking. The results have clearly shown that deliberate choice of the binder used in the asphalt mixture for the overlay will significantly improve its reflective cracking resistance or even fatigue resistance.
INFLUENCE OF DATA NORMALIZATION ON THE EFFECTIVENESS OF NEURAL NETWORKS APPLIED TO CLASSIFICATION OF PAVEMENT CONDITIONS – CASE STUDY
- Karolina Marciniuk
- Bożena Kostek
2018 Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne
In recent years automatic classification employing machine learning seems to be in high demand for tele-informatic-based solutions. An example of such solutions are intelligent transportation systems (ITS), in which various factors are taken into account. The subject of the study presented is the impact of data pre-processing and normalization on the accuracy and training effectiveness of artificial neural networks in the case of pavement condition classification. First, audio parametrization process is shortly described and then the most commonly used methods of data normalization are recalled. Examples of analyses are shown, along with conclusions on application of neural networks to pavement moisture condition classification. A neural network based on the Java Neuroph library was designed. Training time and the network evaluation efficiency of the data without and with normalization performed were shown and analyzed. As it turns out, the Z-score normalization is the most accurate, and also the fastest one for the dataset gathered.
Influence of different cultivation systems on bioactivity of asparagus
- Yang-Gyu Ku
- Dong Kang
- Choung Lee
- Si Lee
- Chan Ryu
- Dong Kim
- Martin Polovka
- Jacek Namieśnik
- Shela Gorinstein
2018 FOOD CHEMISTRY
Evaluation of functional and bioactive compounds of Asparagus officinalis L. growing in conventional and organic greenhouse and conventional open –field farming was the aim of this research. Polyphenols in cladodes grown conventionally were higher than organic. Flavonoids and carotenoids were the highest in cladodes in open field. Organic spears were richer in total phenolics (+6.9% and +19.1%) and flavonoids (+4.7% and 16.8%) and showed higher in vitro averages of antioxidant activities by three radical scavenging assays (+12.5% and+ 22.2%) than conventional. Partial differentiation of organically and conventionally grown samples was proved by multivariate statistics. The binding properties of polyphenols to HSA were relatively high in comparison with other plants. A strong positive correlation of binding properties and bioactivity of asparagus was estimated. All new found aspects for the first time lead to recommendation of inclusion of all investigated asparagus plants into the human diet in a wider scale.
Influence of Diosmin Treatment on the Level of Oxidative Stress Markers in Patients with Chronic Venous Insufficiency
- Marcin Feldo
- Michał Woźniak
- Magdalena Wójciak-Kosior
- Ireneusz Sowa
- Agata Kot-Wasik
- Justyna Aszyk
- Jacek Bogucki
- Tomasz Zubilewicz
- Anna Bogucka-Kocka
2018 Pełny tekst Oxidative Medicine and Cellular Longevity
Oxidative stress plays an important role in the pathophysiology of many human disorders, while antioxidants prevent the development of various adverse symptoms. Diosmin is a natural flavonoid applied in vascular system disorders, especially in chronic venous insufficiency (CVI), and it plays a significant part in the alleviation of CVI symptoms. Due to antioxidant activity, it also has the ability to scavenge the oxygen free radicals and hence decreases the level of oxidative stress biomarkers, such as prostaglandins and their precursors—isoprostanes. In the study, the influence of diosmin treatment on the level of isoprostanes in plasma samples of patients suffering from CVI was examined. The qualitative analysis was performed using high-performance liquid chromatography with spectrometry detection (LC-MS). The statistically significant decrease of isoprostane content after 3 months of treatment was observed within the studied group; however, the most significant changes were observed in patients who smoke.
Influence of dopants on structure of polycrystalline bismuth niobate
- Dionizy Czekaj
- Agata Lisińska-Czekaj
2018 Pełny tekst Advances in Materials Science
Bismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. BiNbO4 ceramics was fabricated by mixed oxide method and sintered at temperature T<1000˚C. As the sintering aids a small amount of CuO oxide was used. The crystalline structure of the ceramic samples was examined by X-ray diffraction method at room temperature. The Rietveld refinement method was used for analysis of diffraction data. As a result an influence of dopants on crystal structure of bismuth niobate (BiNbO4) ceramics was revealed. It was found that fabricated BiNbO4 ceramics adopted the orthorhombic symmetry (αBiNbO4 phase, Pnna (52) space group). Small differences in elementary cell parameters were found.
Influence of ESPAR antenna radiation patterns shape on PPCC-based DoA estimation accuracy
- Mateusz Rzymowski
- Łukasz Kulas
2018
In the article, we show the influence of three different electronically steerable parasitic array radiator (ESPAR) antenna radiation patterns on the overall direction of arrival (DoA) estimation accuracy when power-pattern cross-correlation (PPCC) algorithm, relying on received signal strength (RSS) values, is used for the estimation. The ESPAR antenna designs were obtained for three optimization goals, which resulted in different radiation patterns. To check the applicability of every ESPAR antenna to wireless sensor network (WSN) applications, we have verified their achievable DoA estimation accuracy in numerical tests. The results indicate, that it is possible to provide an ESPAR antenna design for WSN applications, which have narrow radiation pattern and also provide acceptable DoA estimation accuracy.
Influence of excitons interaction with charge carriers on photovoltaic parameters in organic solar cells
- Damian Głowienka
- Jędrzej Szmytkowski
2018 Pełny tekst CHEMICAL PHYSICS
We report on theoretical analysis of excitons annihilation on charge carriers in organic solar cells. Numerical calculations based on transient one-dimensional drift-diffusion model have been carried out. An impact of three quantities (an annihilation rate constant, an exciton mobility and a recombination reduction factor) on current density and concentrations of charge carriers and excitons is investigated. Finally, we discuss the influence of excitons interaction with electrons and holes on four photovoltaic parameters (a short-circuit current, an open-circuit voltage, a fill factor and a power conversion efficiency). The conclusion is that the annihilation process visibly decreases the efficiency of organic photocells, if the annihilation rate constant is greater than 10E-15 m3s-1.
Influence of fasteners and connections flexibility on deflections of steel building including the stressed skin effect
- Natalia Korcz-Konkol
- Elżbieta Urbańska-Galewska
2018 Pełny tekst Technical Sciences / University of Warmia and Mazury in Olsztyn
The paper presents the analysis of the influence of fasteners and connections flexibility on displacements of symmetrical single-bay pitched-roof steel building, including trapezoidal cladding acting as a diaphragm. The purpose of the article was to compare numerical models with and without taking into consideration fasteners and connections flexibility in order to observe the differences in transverse stiffness of the building during modifying model from the simple one to more complex and precise. The analyses were carried out for the 3D structure. Fasteners and connections were substituted by equivalent beam finite elements. Corrugated sheets were replaced by three types of equivalent orthotropic shell models and the influence of the choice of the model on the stiffness of the building was observed. The results showed that in the analysed structure the flexibility of fasteners and connections has negligible effect on transverse displacements of the building in the case of four sides fastening of the sheeting, however in the case of two sides fastening the influence significantly increases.
Influence of geotechnical conditions on damage states of Gdansk Bay Coast cliff formations
- Eligiusz Mieloszyk
- Mariusz Wyroślak
2018 Pełny tekst Polish Maritime Research
A geotechnical aspect of destruction processes of seashores was identified based on the case of erosion of Gdansk Bay Coast cliff formations. Causative factors of landslide were described in the context of natural phenomena, land development and its anthropogenic transformations. Possible directions of theoretical analysis of changes in groundwater relations were indicated.
Influence of lubricating oil improvers on performance of crankshaft seals
- Piotr Bzura
2018 Pełny tekst Polish Maritime Research
This paper presents an original method for checking influence of lubricating oil improvers on performance of crankshaft seals of combustion piston engine. Crankshaft seals were tested with the use of a modified friction node of T-02 four- ball apparatus in laboratory conditions. The tests were conducted according to a worked-out algorithm. Their results confirmed usefulness of the method for determining „harmful” performance of sealing systems, which makes it possible to assess operational usability of lubricating oil improvers. On the basis of an analysis of the results a scientific hypothesis saying that lubricating oil quality affects correctness of performance of crankshaft seals of combustion piston engine, was formulated. The hypothesis was verified by means of induction inference and statistical method with taking into account Fisher statistics.
Influence of Natural Conditions on the Imaging of the Bottom of the Gdańsk Bay by Means of the Side Scan Sonar
- Dominika Witos-Okrasińska
- Grażyna Grelowska
- Eugeniusz Kozaczka
2018 Pełny tekst Polish Maritime Research
The interest in underwater resources is the reason for the development of modern hydroacoustic systems, including side sonars, which find numerous applications such as: research of seabed morphology and sediment characteristics, preparation of sea sediment maps, and even in special cases of biocenoses such as sea grass meadows, detection of specific targets at the bottom such as shipwrecks, mines, identification of suitable sites for maritime infrastructure. Such applications require precise information about the position of the objects to be observed. Errors affecting the depiction of the bottom using hydroacoustic systems can be divided into errors associated with improper operation of measuring and support devices, systematic errors and random errors. Systematic errors result from the changing conditions prevailing in the analyzed environment affecting the measurement system. The errors affecting the correct operation of hydroacoustic systems can include: changing angle of inclination of the beam caused by the vessel’s movement on the wave or refraction connected to changes in the sound speed as the depth function.
Influence of nonlinearities on the efficiency and accuracy of FEM calculations on the example of a steel build-up thin-walled column
- Patryk Deniziak
- Karol Winkelmann
2018 Pełny tekst MATEC Web of Conferences
Due to the increase of computing capabilities of standard processing units, it is possible to perform complex analyses, considering a number of nonlinearities, such as geometric, material and boundary (contact) even on personal computers. In the paper, the authors have analysed the efficiency and accuracy of standard PC’s FEM calculations performed in Abaqus CAE 2017 software on the example of a critical load assessment of a thin-walled steel column element with selected nonlinearities. A cross-section shape of a built-up column used by an international steel structures manufacturer was adopted. The analysis serves to check the behavior of their product. Several types of FEM analysis, strictly based on the EN standard regulations were performed. In turn, the relation of computational time to the adopted analysis type was obtained. Moreover, the produced load values in different types of independent calculation were compared and analysed. A possible future development in the field, based mainly on full-scale experimental tests, was also highlighted.
Influence of parameters of deep grinding on nanohardness and surface roughness of C45 steel
- Mariusz Deja
- Alicja Stanisławska
- Marek Szkodo
- Karolina Wszelak
2018 Pełny tekst Mechanik
Przedstawiono wyniki badań wpływu głębokości współbieżnego szlifowania powierzchni płaskich na chropowatość i nanotwardość warstwy wierzchniej stali C45 o strukturze ferrytyczno-perlitycznej i średniej wielkości ziarna 20 μm. Dla wszystkich wartości głębokości szlifowania uzyskano znaczny wzrost twardości warstwy wierzchniej przedmiotu obrabianego.
Influence of passive house technology on time and cost of construction investment
- Magdalena Apollo
- Emilia Miszewska
2018 Pełny tekst
Due to the changes in the energy standards for housing in Poland there are many concerns. Is the standard required by the regulation achievable and if it is, then at what cost? There are many solutions to construct a building in line with the requirements of passive house technology. They are differentiated by price and time required for implementation. This study is based on the solution proposed by one of Polish companies, offering technologically integrated products allowing, according to the producer, to build passive houses faster and easier. The goal of this study was to confront producer’s claim with reality by comparing time and cost of the same investment using conventional and passive house technology. The basis for time and cost analysis was a basic detached house design, partially modified with regards to materials and technology used. Conclusions of the study are based on the comparison of the two Gantt charts defined in Ms Project. Construction schedule was used to analyse the duration of both projects and the resources assignment was used in cost analysis.
Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering.
- Vitezslav Stranak
- Zdenek Hubicka
- Martin Cada
- Robert Bogdanowicz
- Harm Wulff
- Christine Helm
- Rainer Hippler
2018 Pełny tekst JOURNAL OF PHYSICS D-APPLIED PHYSICS
Iron oxide films were deposited using high power impulse magnetron sputtering (HiPIMS) of an iron cathode in an argon/oxygen gas mixture at different gas pressures (0.5~Pa, 1.5~Pa, and 5.0~Pa). The HiPIMS system was operated at a repetition frequency $f = 100$~Hz with a duty cycle of 1~\%. A main goal is a comparison of film growth during conventional and electron cyclotron wave resonance-assisted HiPIMS. The deposition plasma was investigated by means of optical emission spectroscopy and energy-resolved mass spectrometry. Active oxygen species were detected and their kinetic energy was found to depend on the gas pressure. Deposited films were characterized by means of spectroscopic ellipsometry and grazing incidence x-ray diffraction. Optical properties and crystallinity of as-deposited films were found to depend on the deposition conditions. Deposition of hematite iron oxide films with the HiPIMS-ECWR discharge is attributed to the enhanced production of reactive oxygen species.
Influence of selected additives and admixtures on underwater concrete and the environment
- Aleksandra Kuryłowicz-Cudowska
- Lucyna Grabarczyk
- Barbara Wojtasik
- Małgorzata Zbawicka
2018 Pełny tekst MATEC Web of Conferences
The intensive civilization development has an influence on searching for new possibilities connected with extension of city agglomerations, both the areas of flat building and the industrial areas. One of the most interesting solution is to use water reservoirs, rivers and sea areas. The extension of buildings has an influence on building materials, especially hydrotechnical, which means development of production of hydrotechnical concrete. Water structures are usually the objects of huge dimensions exposed to extreme conditions. In most cases those buildings are very specific and complicated. They require an individual approach to concrete mix design and should be monitored by measurement technologies supported by automated numerical examinations. Nowadays health monitoring systems are applied to large variety of engineering structures including underwater concrete objects. In order to get the needed quality of hydrotechnical concrete mixtures, special additives and admixtures need to be used. The material properties of underwater concrete can also be improved by using polymer and steel fibers in different content and different length. Majority of areas are built of concrete, that is why we need to be aware of admixture influence on the environment and living organisms. The attempt to evaluate the description of different kinds of hydrotechnical concrete as potential habitation of water organisms, was indicated in this paper.
Influence of selected WMA additives on viscoelastic behaviour of asphalt mixes and pavements
- Marcin Stienss
- Łukasz Mejłun
- Józef Judycki
2018 International Journal of Pavement Engineering
Warm mix asphalt additives are effective in decreasing production, laying and compaction temperatures of asphalt mixes. However, there are still questions concerning influence of warm mix additives on properties of asphalt mixes and pavement performance. This paper presents results of the comprehensive research of viscoelastic behaviour of asphalt mixes and pavement structures with layers made with warm mix asphalt additives at high temperatures. Two additives of significantly different effects on mixes at higher temperatures were selected for analysis, namely aliphatic synthetic wax produced with the use of Fisher–Tropsch method and formulation of surfactant- based molecules (ionic and non-ionic). Viscoelastic properties of mixes with these two additives and, as a reference mix, with neat unmodified asphalt binder were determined in uniaxial compression with sinusoidal loading using Asphalt Mixture Performance Test. The viscoelastic analysis of pavement structures was performed with use of the VEROAD software and data from laboratory testing. Two different pavement structures were analysed, for light and heavy traffic. The temperature distribution in pavement structure during the hottest summer day in northern Poland in 2012 was taken into account. The model of pavement was loaded with moving wheel at different speeds. The analysis has shown that two tested warm mix additives had different effect on viscoelastic transient response at high temperatures. One of them (Fischer–Tropsch wax) evidently caused an increase in resistance of asphalt mix and pavement structure to loading at high temperature. The second additive (formulation of surfactant-based molecules) slightly reduced resistance of asphalt mix and pavement to loading at high temperatures as compared with the reference mix.
Influence of service ageing on polyester-reinforced polyvinyl chloride-coated fabrics reported through mathematical material models
- Krzysztof Żerdzicki
- Paweł Kłosowski
- Krzysztof Woznica
2018 TEXTILE RESEARCH JOURNAL
In this paper the coupled service (constructional tension) and environmental (sunlight, rainfalls, temperature variations) ageing influence on the polyester-reinforced polyvinyl chloride (PVC)-coated fabric VALMEX is studied. Two cases of the same fabric have been analyzed: one USED for 20 years on the real construction of the Forest Opera in Sopot (Poland), and one kept as a spare material (NOT USED). The following tests have been conducted: uniaxial tensile, biaxial tensile and long-term creep tests. The obtained results have been used for the parameter identification of the piecewise nonlinear, Burgers and Bodner–Partom models. Next, the analysis of the influence of environmental conditions on the parameters of these models has been made. It has been concluded that some parameters are more and the others are less sensitive to the exposure to environmental and mechanical conditions. The change of material parameters for fill threads (due to larger deformation) is higher. The obtained results may be useful in the durability evaluation of the textile membranes reinforced with polyester threads and PVC coated. All the constitutive models with the identified parameters may be used for the numerical analysis of structures made of fabrics at the service beginning and after long-term usage.
Influence of sheet/purlin fasteners spacing on shear flexibility of the diaphragm
- Natalia Korcz-Konkol
- Elżbieta Urbańska-Galewska
2018 Pełny tekst MATEC Web of Conferences
The paper presents the influence of sheet/purlin fasteners location (in reference to trapezoidal profile cross section) on shear flexibility of the cladding acting as a diaphragm. Analytical procedures were presented and their limitations were discussed. Next, selected schemes of fasteners location, known from engineering practice, but not included in European codes and recommendations, were analysed numerically in order to observe the differences in shear stiffness of the panel. The cantilevered diaphragm as a part of the roof of a single storey building was chosen for the analysis. The analysis was carried out for the valley-fixed trapezoidal sheeting with wide pans. Corrugated sheets were built by two types of models: full 3D shell model and equivalent orthotropic 2D shell model. Flexibility of fasteners and connections was included in the calculations using equivalent beam finite elements. The results were discussed from the stressed-skin design point of view.