2017 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2017

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Some geomechanical properties of a biopolymer treated medium sand
- Mateusz Wiszniewski
- Zdzisław Skutnik
- Marcin Biliniak
- Ali Firat Cabalar
2017 Pełny tekst Annals of Warsaw University of Life Sciences-SGGW Land Reclamation
Some geomechanical properties of a biopolymer treated medium sand. This paper presents a laboratory assessment of geomechanical properties of sandy soil improved by biopolymer application. Additives (biosubstance) consist of polysaccharides and water. Biosubstance used in the project was xanthan gum, which comes from bacteria Xanthomonas campestris. Triaxial shear compression tests and unconfi ned compression tests were carried out for investigation purposes. Amount of the biopolymer used in the samples was 0.5, 1.0 and 1.5%, on dry weight basis. It is thought that such application, which is a relatively new technique, could be used as a ground improvement and water seepage barrier, required to strengthen and protect some geotechnical works including foundation, underground structures and waste disposals. The results indicate that behavior of the soil changes rapidly based on the amount of biosubstance. Shear strength parameters have shown a signifi cant increase, which gives a chance for further development and possible applications.
Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
- Karol Abratkiewicz
2017 Pełny tekst HYDROACOUSTICS
This paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in the function of chirp rate. The proposed method relies on chirp rate estimation of the received signal, and the calculation of the local threshold level depends on noise and reverberations which make detection of a particular type of signal possible.
Sorption properties of asphaltene stationary phases for gas chromatography separations
- Maksymilian Plata-Gryl
- Grzegorz Boczkaj
2017 Pełny tekst Camera Separatoria
W pracy przedstawiono wyniki badań nad możliwością wykorzystania faz stacjonarnych na bazie frakcji asfaltenowych do rozdzielania mieszanin związków chemicznych z wykorzystaniem chromatografii gazowej oraz porównano selektywność faz przygotowanych z frakcji asfaltenowych wyizolowanych z różnych surowców. Na podstawie uzyskanych wyników obliczono wartości liniowych indeksów retencji oraz stałych Rohrschneidera McReynoldsa, za pomocą których charakter badanych faz określono jako średniopolarny. Przeprowadzone badania wykazały, że przygotowane fazy stacjonarne pozwalają na rozdzielenie związków w ramach grup związków tj. węglowodory aromatyczne, ketony, alkohole, sulfidy. Ponadto zaobserwowano różnice w selektywności faz stacjonarnych w zależności od surowca z jakiego były wyizolowane
Sound intensity distribution around organ pipe
- Piotr Odya
- Józef Kotus
- Maciej Szczodrak
- Bożena Kostek
2017 Pełny tekst Archives of Acoustics
The aim of the paper was to compare acoustic field around the open and stopped organ pipes. The wooden organ pipe was located in the anechoic chamber and activated with a constant air flow, produced by an external air-compressor. Thus, long-term steady state response was possible to obtain. Multichannel acoustic vector sensor was used to measure the sound intensity distribution of radiated acoustic energy. Measurements have been carried out on a defined fixed grid of points. A specialized Cartesian robot allowed for a precise positioning of the acoustic probe. Afterwards, the data were processed in order to obtain and visualize the sound intensity distribution around the pipe. The fact of opening or stopping the pipe affects the frequency of the generated sound, the sound pressure level and direction of propagation of acoustic energy. For the open pipe, another sound source was present at the top of the pipe. In this case, the streamlines in front of the pipe are propagated horizontally and in a greater distance from the pipe are directed downwards. For the stopped pipe, the streamlines of the acoustic flow were directed upwards. The results for both pipe types were compared and discussed in the paper.
Sources and fate of microplastics in marine and beach sediments of the Southern Baltic Sea—a preliminary study
- Bożena Graca
- Karolina Szewc
- Danuta Zakrzewska
- Anna Dołęga
- Magdalena Szczerbowska-Boruchowska
2017 Pełny tekst ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Microplastics’ sources and fate in marine bottom and beach sediments of strongly polluted Baltic Sea have been investigated.Microplastics were extracted using sodium chloride. Their qualitative identification was conducted using micro-Fourier-transform infrared spectroscopy (μFT-IR).
Space vector modulation in multilevel inverters of the servo drives of the trajectory measurements telescopes
- Valentin Tomasov
- A Usoltsev
- Denis Vertegel
- Ryszard Strzelecki
2017 Pełny tekst Izvestiya vysshikh uchebnykh zavedeniy. Priborostroenie
Using the MatLab/Simulink mathematical model of a three-phase three-level voltage inverter, the influence of the space-vector modulation (SVM) algorithm on the pulsations of the current (torque) of an AC motor in the range of low rotation speeds is considered. It is shown that the SVM of the second kind does not provide a pulsations level comparable to the pulsations of a sinusoidal pulse-width modulation (SPWM), both in the static mode of the drive operation and in transient modes. In such case, the current pulsations cannot be reduced by changing the modulation algorithm, which almost excludes the possibility of using such transducers in high-quality adjustable instrumental AC electric drives. At the same time, SVM of the first kind can be considered as an alternative to SPWM, as it allows to reduce the current pulsations in the largest part of the control range to a comparable level, and in the last quarter of the control range to values significantly lower than with the SPWM. The asymmetry of the inverter characteristics with the SVM is noted for different directions of the modulation vector rotation.
Space-vector pulsewidth modulation for a seven-level cascaded H-bridge inverter with the control of DC-link voltages
- Arkadiusz Lewicki
- Marcin Morawiec
2017 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences
The control strategy of DC-link voltages for a seven-level Cascaded H-Bridge inverter is proposed in this paper. The DC-link voltage balancing is accomplished by appropriate selection of H-Bridges and control of their duty cycles in Space-Vector Modulation (SVM) algorithm. The proposed SVM method allows to maintain the same voltage level on all inverter capacitors. Regardless of the balancing function, the SVM strategy makes it possible to generate the output voltage vector properly also in the case where the DC-link voltages are not balanced. The results of simulation and experimental investigations are presented in the paper.
Spatial differences in sustainable development components in Nordic regions
- Marta Kuc-Czarnecka
2017 Pełny tekst
Geographical proximity, common historical roots and collaboration within the Nordic Council make the Nordic countries, often wrongly treated as monoliths. How ever, in reality, Nordic regions differ in terms of broadly defined socio - economic development. The aim of this study is to analyze the spatial differences in sustainable development components in Nordic NUTS - 3 regions in the period 2006 - 2014. Each sustain ability dimension is measured using Pietrzak’s spatial taxonomy measure of development. Analyzed problem seems to be important since Nordic countries are currently implementing the Fourth Nordic Strategies for Sustainable Development. The analysis showed t hat the achievement of sustainable development goals manage much better in the Swedish and Norwegian regions. The analysis showed as well that the Nordic countries are not as homogeneous as it might seem at first glance
Spatial pattern of ASG-EUPOS sites
- Beata Calka
- Elzbieta Bielecka
- Mariusz Figurski
2017 Pełny tekst Open Geosciences
The article presents the spatial pattern analysis of the ASG-EUPOS permanent GNSS stations in Poland. Using different methods and tools (nearest neighbour, Riplay’s K-function, morphology of Thiessen polygons) we proved that the station distribution model changes within scales. At short distances up to 65 km, which are typical lengths in the network, stations are irregularly dispersed. Increasing this distance to 130 km and over could result in a clustered pattern. The Thiessen polygon area in 72% depends on the level of urbanization, especially coverage of forested and built-up areas as well as the density of the transportation network. The smallest density of the ASG-EUPOS sites is one station over 10,000 sq. km, which is two times more than is stated in the national regulations. The mean distance from ASG-EUPOS location to the nearest station is about 41.5 km.
Spectral Clustering Wikipedia Keyword-Based search Results
- Julian Szymański
- Tomasz Dziubich
2017 Pełny tekst FRONTIERS IN ROBOTICS AND AI
The paper summarizes our research in the area of unsupervised categorization of Wikipedia articles. As a practical result of our research, we present an application of spectral clustering algorithm used for grouping Wikipedia search results. The main contribution of the paper is a representation method for Wikipedia articles that has been based on combination of words and links and used for categoriation of search results in this repository. We evaluate the proposed approach with Primary Component projections and show, on the test data, how usage of cosine transformation to create combined representations influence data variability. On sample test datasets, we also show how combined representation improves the data separation that increases overall results of data categorization. To implement the system, we review the main spectral clustering methods and we test their usability for text categorization. We give a brief description of the system architecture that groups online Wikipedia articles retrieved with user-specified keywords. Using the system, we show how clustering increases information retrieval effectiveness for Wikipedia data repository.
SPECTRAL-BASED MODAL PARAMETERS IDENTIFICATION WITH MULTIPLE PARTICLE SWARMS OPTIMIZATION
- Adrian Orzechowski
- Marek Galewski
2017
The paper presents usage of a Particle Swarm Optimization [1] based algorithm for spectral-based modal parameters identification. The main algorithm consists of two groups of swarms, namely, scouts and helpers. For the first group additional penalizing process is provided to force separation of scouting swarms in frequency space. The swarms have an ability to communicate with each other. At first stage, each swarm focuses on a different natural frequencies dominating in the signal. Next, helper swarms are associated, one by one, with scouting swarms focus on frequency spaces provided by scouting swarms in order to achieve the best representation of a given signal in the frequency domain. At this stage amplitudes and damping coefficients are identified as well. The results from all helpers are then combined to create final identification results.
Spectroscopic and cytotoxic characteristics of (p-cymene)Ru(II) complexes with bidentate coumarins and density functional theory comparison with selected Pd(II) complexes
- Anna Skoczynska
- Karin Lux
- Peter Mayer
- Ingo-Peter Lorenz
- Urszula Krajewska
- Marek Rozalski
- Anna Dołęga
- Elzbieta Budzisz
2017 INORGANICA CHIMICA ACTA
This paper presents the synthesis of two new (p-cymene)-ruthenium(II) complexes with the bidentate coumarin ligands. Both complexes were characterized by FTIR spectroscopy, 1H NMR, 13C NMR, MS, elemental analysis and DFT calculations. The X-ray structure of complex 3a was also solved. The cytotoxic properties of both complexes were examined on human leukemia NALM-6 and HL-60 cells and melanoma WM-115 cells. The complexes possess higher cytotoxic activity than the ligands, The results of DFT calculations performed at the BP86-D3/QZ4P level for Ru(II) complexes and Pd(II) complexes with the same ligands indicate that Pd(II) complexes are more lipophilic. Moreover the RP-TLC-Based Lipophilicity assessment was also performed.
Spectroscopic and magnetic studies of highly dispersible superparamagnetic silica coated magnetite nanoparticles
- Krzysztof Tadyszak
- Ahmet Kertmen
- Emerson Coy
- Ryszard Andruszkiewicz
- Sławomir Milewski
- Irakli Kardava
- Błażej Scheibe
- Stefan Jurga
- Katarzyna Chybczyńska
2017 JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
Superparamagnetic behavior in aqueously well dispersible magnetite core-shell Fe3O4@SiO2 nanoparticles is presented. The magnetic properties of core-shell nanoparticles were measured with use of the DC, AC magnetometry and EPR spectroscopy. Particles were characterized by HR-TEM and Raman spectroscopy, showing a crystalline magnetic core of 11.5 ± 0.12 nm and an amorphous silica shell of 22 ± 1.5 nm in thickness. The DC, AC magnetic measurements confirmed the superparamagnetic nature of nanoparticles, additionally the EPR studies performed at much higher frequency than DC, AC magnetometry (9 GHz) have confirmed the paramagnetic nature of the nanoparticles. Our results show the excellent magnetic behavior of the particles with a clear magnetite structure, which are desirable properties for environmental remediation and biomedical applications.
Specyfika pracy zespołowej
- Paweł Ziemiański
2017
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Specyfika relacji sądów z interesariuszami. W kierunku budowania zaufania do sądów
- Przemysław Banasik
- Sylwia Morawska
- Agata Austen
2017
Społeczna odpowiedzialność instytucji publicznych, w tym sądów, powinna być oparta na etycznych relacjach z interesariuszami. Na obecną chwilę wiedza w zakresie zarządzania relacjami z interesariuszami, w szczególności rozpoznanie motywów, jakie skłaniają decydentów do podejmowania konkretnych działań wobec różnych grup interesariuszy, jest wciąż bardzo słabo rozpoznanym obszarem. Z tego względu w artykule podjęto rozważania dotyczące specyfiki relacji sądów z interesariuszami jakie powinny cechować sąd, aby móc budować ich zaufanie. Przedstawiono wyniki badań ilościowych dotyczących oceny działań podejmowanych przez sąd w oczach sędziów, a także ilości przekazywanych obszarów informacji różnym interesariuszom.
Specyfikacja zadań w procesie tworzenia Komputerowego Modelu Przepływu (KMP)
- Marian Kulbik
2017
W opracowaniu przedstawiono pięć faz i szesnaście zadań, które trzeba wykonać w procesie tworzenia KMP. W każdym zadaniu określono cel, zakres i metodykę jego realizacji. Szczególną uwagę zwrócono na specyfikę postępowania w przewymiarowanych układach wodociągowych.
Speed management on local government managed roads – research, recommendations and guidelines
- Marcin Budzyński
- Stanisław Gaca
- Mariusz Kieć
2017 Pełny tekst MATEC Web of Conferences
Commissioned by the National Road Safety Council Secretariat, the project “Guidelines for speed management on local government managed roads” studied car driver be haviour when subjected to selected speed management measures such a local speed restrictions, surveillance, traffic calming and restricted speed areas. In addition, analyses were conducted on the impact of selected me asures on the level of road safety. The behaviour was assessed by studying the changes in speed parameters (statistical characteristics) for the particular speed management measures or their absence. The road safety level was measured by comparing the level before and after the implementation of the particular speed management measure, taking trends in to account. The paper presents the results of the research, along with recommendations for speed management guidelines.
Speed Sensorless AC Drive with Inverter LC Filter and Fault Detection Using Load Torque Signal
- Jarosław Guziński
- Haitham Abu-Rub
- Patrick Strankowski
2017 Pełny tekst Przegląd Elektrotechniczny
The industrial development in recent years has seen a major increase in the use of induction motors, whereby the cost has to be as low as possible and the lifetime as long as possible. To follow up this desire, investigations in this area have become very intense. For that reason, this paper presents a solution for driving an induction motor and simultaneous fault detection with no need for additional sensors. In order to achieve this target, an observer system is implemented and a torque estimation procedure is used for torque detection. An LC filter was installed at the inverter output to provide better THD of the current. The validation of the drive operation was achieved through simulation and experiments. To investigate possible faults, an artificial unbalance was introduced to the test bench, whereby the experiment was validated by a comparison of physical vibrations and estimated torque.
SPFR - metoda ponownego wykorzystania pasma w systemach radiokomunikacyjnych nowej generacji
- Sławomir Gajewski
2017 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
W referacie zaproponowano nową metodę ponownego wykorzystania pasma częstotliwościowego SPFR (Soft-Partial Frequency Reuse) oraz przedstawiono wyniki badań symulacyjnych, które umożliwiają jej porównanie ze znanymi metodami SFR (Soft Frequency Reuse) i PFR (Partial Frequency Reuse). Metoda SPFR może być użyta do zwiększenia efektywności wykorzystania zasobów fizycznych w systemie LTE-A oraz systemach B4G. Zastosowanie metody SPFR umożliwia znaczące zwiększenie pojemności komórek w ich obszarach granicznych.
Spillover Effect Occurrence in Tricity
- Helena Anacka
- Xaquín Pérez-Sindín
- Hélder Fanha Martins
2017 American Journal of Ancient History
The key topic of this paper is a spillover effect from multinational companies to the local business environment in Tricity. The purpose of the research is to examine whether spillover effect is present in Tricity, to what extent, and, more importantly, what should be the reaction of the local authorities to the results. Based on qualitative interview-based research conducted with the multinational corporations’ employees, spillover effect is present in Tricity to a very limited extent. The reasons could be inappropriate domestic base and infrastructure, inability to absorb the flow of foreign technologies and knowledge from multinational corporations, as well as a lack of universality of skills to be transferred to other companies. The results of the research could be useful for local authorities, research on “spillover effect” scale in Tricity, workers’ mobility, and determining brain drain potential in the region.