2017 - Repozytorium publikacji - Politechnika Gdańska

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Ships - inspiring objects in architecture
- Elżbieta Marczak
2017 Pełny tekst IOP Conference Series: Materials Science and Engineering
Sea-going vessels have for centuries fascinated people, not only those who happen to work at sea, but first and foremost, those who have never set foot aboard a ship. The environment in which ships operate is reminiscent of freedom and countless adventures, but also of hard and interesting maritime working life. The famous words of Pompey: “Navigare necesseest, vivere non estnecesse” (sailing is necessary, living – is not necessary), which he pronounced on a stormy sea voyage, arouse curiosity and excitement, inviting one to test the truth of this saying personally. It is often the case, however, that sea-faring remains within the realm of dreams, while the fascination with ships demonstrates itself through a transposition of naval features onto land constructions. In such cases, ship-inspired motifs bring alive dreams and yearnings as well as reflect tastes. Tourism is one of the indicators of people’s standard of living and a measure of a society’s civilisation. Maritime tourism has been developing rapidly in recent decades. A sea cruise offers an insight into life at sea. Still, most people derive their knowledge of passenger vessels and their furnishings from the mass media. Passenger vessels, also known as “floating cities,” are described as majestic and grand, while their on-board facilities as luxurious, comfortable, exclusive and inaccessible to common people on land. Freight vessels, on the other hand, are described as enormous objects which dwarf the human being into insignificance. This article presents the results of research intended to answer the following questions: what makes ships a source of inspiration for land architecture? To what extent and by what means do architects draw on ships in their design work? In what places can we find structures inspired by ships? What ships inspire architects? This article presents examples of buildings, whose design was inspired by the architecture and structural details of sea vessels. An analysis of these examples formed the basis for an evaluation of the impact of this inspiration on the shaping of public spaces and the aesthetic aspect of architectural structures.
Shooting Gas Cylinders to Prevent Their Explosion in Fire
- Jerzy Ejsmont
- Beata Świeczko-Żurek
- Grzegorz Ronowski
2017 Pełny tekst
Gas cylinders in general, and particularly cylinders containing acetylene, constitute a great potential danger to fire and rescue services involved in salvage operations. Experiments show that gas cylinders with acetylene, oxygen, hydrogen, CNG, LPG or CO2 may blow after short exposition to heat with very destructive effect as fragments of blown cylinder may fly even several hundred meters. In the case of acetylene the explosion may occur also several hours after the cylinder is cooled down. One of the possible neutralization procedures that in many cases may be used to prevent explosions is shooting dangerous cylinders with rifle bullets. This technique is used to neutralize acetylene cylinders in a few European countries with great success. In Poland research project "BLOW" was launched in 2014 with the aim to investigate phenomena related to fire influence on industrial and home used cylinders and to evaluate usefulness of the shooting technique. All together over 100 gas cylinders with different gases were experimentally tested at the military blasting grounds and in shelters. During the experiments cylinder temperature and pressure were recorded. In the case of acetylene that is subjected to thermal decomposition also concentration of hydrogen was monitored. Some of the cylinders were allowed to blow and others were shot by snipers. It was observed that shooting hot cylinders has never created more dangerous situations than letting the cylinders to explode spontaneously. In a great majority of cases cylinders that were punctured with bullets released gas in a more or less violent but relatively safe way. The paper presents detailed information about experiments and presents particularities of behavior of cylinders containing different gases. Extensive research was also done in order to select bullets that may be safely and efficiently used to puncture different cylinders. The paper shows also results of those experiments as well as gives practical information related to techniques that should be used during shooting.
SiC-based T-type modules for multi-pulse inverter with coupled inductors
- Jacek Rabkowski
- Tomasz Sak
- Ryszard Strzelecki
- Maciej Grabarek
2017
The paper presents SiC-based three-level T-type modules designed for a high-performance 30kVA DC/AC inverter operating at high frequency 85 kHz with low THD of the output voltage. This inverter system consists of two integrated parts. The first part is active and contains three parallelconnected three-phase T-type modules built with fast-switching SiC power transistors. The second, passive part of the system is a set of inductors magnetically coupled in the system 18-pulse. Such a system is able to generate near sinusoidal output voltage without PWM operation – transistors operate at switching frequency close to output frequency. The paper discusses design issues of the module with SiC transistors including design of the gate drivers. Moreover, experiments with single phase leg operating at nominal conditions are also presented.
Sieć sensorowa do rejestracji drgań górnej sieci trakcyjnej w celach diagnostyki eksploatacyjnej
- Krzysztof Karwowski
- Marek Kuciński
- Mirosław Mizan
- Andrzej Wilk
2017 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Wraz ze wzrostem prędkości kolejowych pojazdów elektrycznych zwiększają się wymagania utrzymania sieci trakcyjnej w odpowiednim stanie technicznym. Ciągły monitoring i diagnostyka pozwalają wykrywać pogarszającą się jakość odbioru prądu z sieci jezdnej. Jedną z metod jest umieszczenie czujników przyspieszenia na przewodzie jezdnym. Analiza przebiegu przyspieszenia pozwala określić jakość współpracy sieci jezdnej z pantografem. Symulacja dynamiki takiego układu ułatwia dobór parametrów akcelerometrów. Wykorzystanie bezprzewodowej sieci sensorowej redukuje konieczność izolacji elektrycznej czujników od sieci trakcyjnej. W artykule omówiono projekt i realizację sieci sensorowej do rejestracji przyspieszeń przewodów sieci jezdnej. Zaprezentowano wstępne wyniki pomiarów laboratoryjnych.
Siedmiokryterialny miernik oceny niepotokowych procesów produkcyjnych
- Alicja Kukułka
2017 Pełny tekst Zarządzanie Przedsiębiorstwem
Growing expectations of clients, who demand products adapted to their individual needs is inducing the development of batch processes. The author developed a model of batch processes rating based on the following criterions: • Economical criterion applies to evaluation of the productions’ cost levels connected with the process subjected to analysis and necessary investment funds. • Ecological criterion is about means of natural environment protection, utilization and segregation of wastes and usage of various media. This criterion is about social responsibility of companies. • Social criterion concerns working conditions (ergonomics on work centers), requirements on personnel qualifications and satisfaction from work - rated for example by measuring absence at work or with survey. • The market criterion is about evaluation if the product or additional services meet clients’ individual needs and if the prices and time between the product beening ordered and delivered to the client are elastic. It is about evaluation of product based on clients’ point of view. • Technological criterion, which concerns implementation of production process course, is based on machines’ work and production workers’ work evaluation. • General development criterion allows the evaluation of a companies’ state not only by measuring fulfilled production processes, but by its general condition as well. • Planning criterion is related to fulfilling general production schedules, which is one of the main targets of production control For each criterion the authors performed selection of indicators, which enable evaluation of the process. Developed conception allows performing complex and synthetic evaluation of batch processes.
Silver complexes stabilized by large silanethiolate ligands – crystal structures and luminescence properties
- Anna Ciborska
- Zbigniew Hnatejko
- Katarzyna Kazimierczuk
- Agnieszka Mielcarek
- Aleksandra Wiśniewska
- Anna Dołęga
2017 DALTON TRANSACTIONS
Bulky silanethiolate and disiladithiolate ligands were applied to synthesize one mononuclear and three trinuclear silver complexes including two cyclic “microclusters” and a linear tri-nuclear silanethiolate complex. All obtained compounds are characterized by X-ray diffraction and FT-IR. NMR and emission spectroscopies were used where possible. The first trinuclear anionic silver thiolate is structurally characterized. The influence of the different charge of cyclic silver complexes as well as the overall ligand environment on the structural properties is demonstrated. The impact of the different synthetic routes on the final structures of the obtained clusters – cyclic or linear – is discussed.
Similarities and Differences Between the Vertex Cover Number and the Weakly Connected Domination Number of a Graph
- Magdalena Lemańska
- Juan A. RODRíGUEZ-VELáZQUEZ
- Rolando Trujillo-Rasua
2017 FUNDAMENTA INFORMATICAE
A vertex cover of a graph G = (V, E) is a set X ⊂ V such that each edge of G is incident to at least one vertex of X. The ve cardinality of a vertex cover of G. A dominating set D ⊆ V is a weakly connected dominating set of G if the subgraph G[D]w = (N[D], Ew) weakly induced by D, is connected, where Ew is the set of all edges having at least one vertex in D. The weakly connected domination number γw(G) of G is the minimum cardinality among all weakly connected dominating sets of G. In this article we characterize the graphs where γw(G) = τ (G). In particular, we focus our attention on bipartite graphs, regular graphs, unicyclic graphs, block graphs and corona graphs.
Simple 2-D Direction-of-Arrival Estimation Using an ESPAR Antenna
- Łukasz Kulas
2017 Pełny tekst IEEE Antennas and Wireless Propagation Letters
In this letter, it has been shown how an electronically steerable parasitic array radiator (ESPAR) antenna can be used for 2-D direction-of-arrival (DoA) estimation employing received signal strength (RSS) values only. The proposed approach relies on changes in RSS values recorded at the antenna output port observed for different vertical and horizontal directions, while antenna’s main beam sweeps 360° area around the ESPAR antenna. Based on the observed diversity in RSS values, obtained for different ESPAR antenna radiation patterns and different directions of a signal impinging the antenna, a simple 2-D DoA estimator has been proposed. Measurements using the fabricated ESPAR antenna indicate that, by relying solely on RSS values and the proposed algorithm, it is possible to perform 2-D DoA estimation with the acceptable accuracy in realistic and inexpensive systems, where the phase of impinging signals cannot easily be measured.
Simple empirical formula to estimate the main geomechanical parameters of preplaced aggregate concrete and conventional concrete
- Ali M. Rajabi
- Farzam Omidi Moaf
2017 CONSTRUCTION AND BUILDING MATERIALS
Preplaced aggregate concrete (PAC) or two-stage concrete is a specific type of concrete successfully employed in many projects including underwater concrete structures, massive concrete structures, structures made of reinforced concrete, and improvement of concrete structures. PAC is significantly different than the conventional concrete. In this type of concrete, aggregates are initially poured into the mold, the voids between which are then filled with sand and cement mortar. Additionally, the concrete provides grain-to-grain contact for the aggregates. Since use of PAC in construction projects is growing, this paper is aimed to present experimental relations for estimation of geomechanical parameters of PAC and conventional concrete. To this end, 144 and 72 specimens made of PAC and conventional concrete, respectively, were prepared, on which uniaxial compression test, Brazilian tensile test, and point load test were conducted. Then, the resulting data from the experiments were classified into two categories, namely the regression and the test data. Moreover, experimental relations were obtained between the compressive strength, tensile strength, Young’s modulus, corrected point load index, and Poisson’s ratio for both conventional concrete and PAC, and their validity were then investigated. The results indicated that the obtained relations could be used to estimate the geomechanical properties of PAC and conventional concrete with acceptable accuracy.
Simplified AutoDock force field for hydrated binding sites
- Marek Wojciechowski
2017 Pełny tekst JOURNAL OF MOLECULAR GRAPHICS & MODELLING
has been extracted from the Protein Data Bank and used to test and recalibrate AutoDock force field. Since for some binding sites water molecules are crucial for bridging the receptor-ligand interactions, they have to be included in the analysis. To simplify the process of incorporating water molecules into the binding sites and make it less ambiguous, new simple water model was created. After recalibration of the force field on the new dataset much better correlation between the computed and experimentally determined binding affinities was achieved and the quality of pose prediction improved even more
Simplified numerical model for global stability of corrugated silos with vertical stiffeners
- Piotr Iwicki
- Karol Rejowski
- Andrzej Tejchman-Konarzewski
2017 JOURNAL OF CONSTRUCTIONAL STEEL RESEARCH
Artykuł omawia wyniki stateczności globalnej silosów z blachy falistej z pionowymi usztywnieniami. Zaproponowano uproszczony model numeryczny metody elementów skończonych do określenia stateczności. Wyniki numeryczne były bardziej dokładnie niż metody zaproponowane w Eurokodzie.
SIMPLY AND LOW COAST ELECTROMYOGRAPHY SIGNAL AMPLIFIER
- Robert Barański
- Anna Grzeczka
2017 Pełny tekst Diagnostyka
Recently, there has been a noticeable increase in interest in solu tions utilizing electrical signals accompanying muscle activity. Electromyography (EMG) is a technique for recording, analysis and evaluating the electrical activity produced by striated muscle. Its great popularity is due, among other, to the ability to measure with non-invasive electrodes (calle d as sEMG surface electromyography). However, the limitations of this method are the high costs of specia lized measuring equipment, and in particular the systems of bioelectric signal preamplifier circuits. The work presents the design of a low budget EMG signal amplifier. It has been designed and validated in accordance with ISEK (International Society of Electrophysiology and Kinesiology) and SENIAM (Surface ElectroMyGraphy for Non-Invasive Assessment of Muscles).
Simulating propagation of coherent light in random media using the Fredholm type integral equation
- Maciej Kraszewski
- Jerzy Pluciński
2017 Pełny tekst
Studying propagation of light in random scattering materials is important for both basic and applied research. Such studies often require usage of numerical method for simulating behavior of light beams in random media. However, if such simulations require consideration of coherence properties of light, they may become a complex numerical problems. There are well established methods for simulating multiple scattering of light (e.g. Radiative Transfer Theory and Monte Carlo methods) but they do not treat coherence properties of light directly. Some variations of these methods allows to predict behavior of coherent light but only for an averaged realization of the scattering medium. This limits their application in studying many physical phenomena connected to a specific distribution of scattering particles (e.g. laser speckle). In general, numerical simulation of coherent light propagation in a specific realization of random medium is a time- and memory-consuming problem. The goal of the presented research was to develop new efficient method for solving this problem. The method, presented in our earlier works, is based on solving the Fredholm type integral equation, which describes multiple light scattering process. This equation can be discretized and solved numerically using various algorithms e.g. by direct solving the corresponding linear equations system, as well as by using iterative or Monte Carlo solvers. Here we present recent development of this method including its comparison with well-known analytical results and a finite-difference type simulations. We also present extension of the method for problems of multiple scattering of a polarized light on large spherical particles that joins presented mathematical formalism with Mie theory.
Simulation of the remanence influence on the transient states in a single-phase multiwinding transformer
- Andrzej Wilk
- Michał Michna
2017 Pełny tekst Archives of Electrical Engineering
This paper presents the mathematical model of a single-phase multi-winding core type transformer taking into account magnetic hysteresis phenomenon based on the feedback Preisach model (FPM). The set of loop differential equations was developed for a K-th winding transformer model where the flux linkages of each winding includes flux Φ common to all windings as a function of magneto motive force Θ of all windings. The first purpose of this paper is to implement a hysteresis nonlinearity involved in the Φ(Θ) function which also accounts residual magnetic flux. The second purpose of this paper is experimental validation of the developed transformer model in a capacitor discharge test and several different values of residual magnetic flux.
Simulation studies into quayside transport and storage yard operations in container terminals
- Mariusz Deja
- Michał Dobrzyński
- Mieczysław Siemiątkowski
- Aleksandra Teresa Wiśniewska
2017 Pełny tekst Polish Maritime Research
The focus of the paper is on quayside transport and storage yard operations in the sea container terminals. Developed algorithms for solving the issues of load handling and storage space allocation have been applied in the frame of adopted simulation model. The criteria chosen for decision making involved the total makespan of vessel unloading and the utilisation levels of the transportation trucks. Recommendations for unloading in berth space and yard areas were analysed throughout three different case studies. Further on, results of the analyses were discussed, based on both deterministic modelling scheme and performed simulation runs.
Simultaneous determination of individual isothiocyanates in plant samples by HPLC-DAD-MS following SPE and derivatization with N-acetyl-l-cysteine
- Tadeusz Pilipczuk
- Barbara Kusznierewicz
- Tomasz Chmiel
- Witold Przychodzeń
- Agnieszka Bartoszek-Pączkowska
2017 Pełny tekst FOOD CHEMISTRY
The procedure for the isothiocyanates (ITCs) determination that involves derivatization with N-acetyl-l-cysteine (NAC) and separation by HPLC was developed. Prior to derivatization, plant ITCs were isolated and purified using solid-phase extraction (SPE). The optimum conditions of derivatization are: 500 μL of isopropanolic eluate obtained by SPE combined with 500 μL of derivatizing reagent (0.2 M NAC and 0.2 M NaHCO3 in water) and reaction time of 1 h at 50 °C. The formed dithiocarbamates are directly analyzed by HPLC coupled with diode array detector and mass spectrometer if required. The method was validated for nine common natural ITCs. Calibration curves were linear (R2 ⩾ 0.991) within a wide range of concentrations and limits of detection were below 4.9 nmol/mL. The recoveries were in the range of 83.3–103.7%, with relative standard deviations <5.4%. The developed method has been successfully applied to determine ITCs in broccoli, white cabbage, garden cress, radish, horseradish and papaya.
Simultaneous determination of Na+, K+, Ca2+, Mg2+ and Cl- in unstimulated and stimulated human saliva using all solid state multisensor platform
- Marcin Urbanowicz
- Artur Jasiński
- Małgorzata Jasińska
- Kamil Drucis
- Arkadiusz Szarmach
- Rafał Suchodolski
- Radosław Pomećko
- Maria Bocheńska
- Marcin Ekman
2017 ELECTROANALYSIS
Human saliva is one of the body fluids which collection method is relatively simple and non-invasive. The article is dedicated to assess concentration (activity) of Na+, K+, Ca2+, Mg2+ and Cl- in fresh, unstimulated or stimulated human saliva samples using single solid contact ion-selective electrodes with conventional reference electrode and self-made multisensor platform (MP) equipped with ion-selective membranes for Na+, K+, Ca2+, Mg2+ and Cl- and reference electrode made in solid state technology, based on dispersed KCl in the polymer. Both kind of electrodes, single ISE and miniaturized electrodes in multisensor platform (ISE-MP) were made of glassy carbon. The electrode surfaces have been modified by conductive polymer (PEDOT) layer deposition; with the exception of Cl- electrode, in which conducting polymer was not applied. Potentiometric measurements were used to compare the changes of the ionic composition in various samples of saliva.
Sinusoidal Alternating-Current Voltammetry and Metrological Properties of a Flat Voltammetric Electrode in the Time Domain
- Krzysztof Suchocki
2017 ELECTROCHIMICA ACTA
In this paper there were analyzed metrological properties of a flat electrode used to mark ions with the method of sinusoidal alternating-current voltammetry in the situation where on its surface an electrochemical reversible reaction of oxidizing / reduction takes place. The result of the analysis conducted is that such a voltammetric electrode functions like a converter type I. Metrological properties of such an electrode in the time domain are defined by the sensitivity and time constant. Values of these parameters are defined by the dimensions which characterize a voltammetric electrode, polarizing voltage and marked ions. Numeric simulations were conducted in order to determine the influence of particular dimensions on the values of the parameters defining the metrological properties. Their results show that the value of the sinusoidal voltage and its frequency have the greatest influence on the values of the parameters.
Sizes of iron hydroxide particles formed during ferric coagulation processes
- Rafał Bray
- Karolina Fitobór
2017 Desalination and Water Treatment
The aim of the study was to apply laser granulometer for measuring sizes of particles formed in iron-based coagulation process in water, which did not contain significant amounts of organic compounds. The research was conducted using tap water, obtained from underground sources. Iron sulfate in doses of 2.0–10.0 mgFe L–1 was added to water. During initial stage of flocculation, iron hydroxide particles reached dimensions between 0.03 and 0.5 μm (at coagulant dose of 2.0 mg Fe L–1) and between 0.1 and 0.5 μm (for higher doses). Maximum dimensions of flocks amounted to 130–500 μm and at doses greater/equal to 4.0 mgFe L–1did not depend on coagulant doses. Merely, for a dose of 2.0 mgFe L–1and after 40 min of flocculation, the flocks reached dimensions of 85–320 μm and continued to enlarge. With increasing dose of coagulant, flocks faster enlarged their dimensions and faster reached maximum sizes. Initially, the smallest particles with dimensions smaller than 0.1 μm still remained in the solution. Persistence of the smallest particles ranged up to 7 min.
Skład chemiczny wód podziemnych piętra czwartorzędowego wybranych obszarów zasilania i drenażu w gdańskim systemie wodonośnym
- Beata Jaworska-Szulc
- Małgorzata Pruszkowska-Caceres
- Maria Przewłócka
2017 Hydrogeologia
Obszar badań należy do gdańskiego systemu wodonośnego. Wzgórza szymbarskie stanowią najwyżej wyniesiony obszar strefy zasilania, o bardzo urozmaiconej morfologii. W utworach czwartorzędu występują trzy poziomy wodonośne o zasięgu regionalnym. Taras nadmorski należy do strefy drenażu; stanowi płaską równinę położoną między krawędzią wysoczyzny i brzegiem morza. W utworach czwartorzędu występuje jeden główny poziom wodonośny plejstoceńsko – holoceński. Badania wykazały różnice w składzie chemicznym wód piętra czwartorzędowego obu analizowanych obszarów, co wynika zarówno ze zróżnicowanych warunków występowania jak i różnego poziomu antropopresji Na wzgórzach szymbarskich chemizm wód kształtowany jest głównie przez czynniki naturalne i jest typowy dla obszarów młodoglacjalnych. Na tarasie nadmorskim skład chemiczny wód kształtowany jest zarówno przez czynniki naturalne jak i antropogeniczne.