2018 - Repozytorium publikacji - Politechnika Gdańska

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Safety Integrity Verification Issues of the Control Systems for Industrial Process Plants
- Kazimierz Kosmowski
2018
The aim of this article is to identify and discuss some issues that can be encountered in designing the industrial automation and control systems (IACS) for implementing safety functions. In a functional safety standard IEC 61511 for the process industry such systems are named the basic process control systems (BPCS) and the safety instrumented systems (SIS). In a generic functional safety standard IEC 61508 they are depicted as the electric / electronic / programmable electronic systems (E/E/PES). The role of these systems is to implement safety functions for effective reducing and controlling the individual risk and/or societal risk in life cycle in relation to tolerable risk levels defined for given hazardous plant. Some aspects of potential influence of danger failures of the E/E/PES or SIS on the plant safety are considered. The influence of common cause failures (CCF) in verifying the safety integrity levels (SIL) achieved by safety functions is evaluated and discussed.
Salt melt synthesis of curved nitrogen-doped carbon nanostructures: ORR kinetics boost
- Maria Rybarczyk
- Emilia Gontarek
- Marek Lieder
- Maria-Magdalena Titirici
2018 APPLIED SURFACE SCIENCE
Implementing metal-free electrocatalysts for the oxygen reduction reaction (ORR) and revealing crucial chemical or topographical parameters driving their activity are vital for the development of power cells. The carbon-based catalysts are very often synthesized through carbonization of biopolymers, in particular, those one containing nitrogen groups such as chitosan. Unfortunately, the resulting carbonaceous materials usually lack specific porosity and exhibit low catalytic activity. Here, we demonstrate that pyrolysis of chitosan in a ZnCl2 melt assisted by the presence of LiCl results not only in a highly porous activated carbon material with a specific surface area of 1317.97 m2/g and the total nitrogen content of 6.5%, but also induces unexpected curvature in the grown graphitic layers. This is the first work that shows curved graphene layers obtained from a biopolymer precursor by its pyrolytic decomposition in the melted salt media. On the other hand, a carbonaceous material obtained from chitosan but without the salts has very low specific surface area of 7.8 m2/g, possesses no specific structural features, and contains 4.7% of nitrogen. The electrochemical studies show, that the former material is highly active towards four-electron pathway of the ORR in terms of an onset potential (0.89 V vs RHE) and the turnover frequency (TOFmax = 0.095 e site−1 s−1). We attribute this high catalytic performance to the presence of the pyridinic and pyrrolic sites in the structure. The ORR kinetics is probably further promoted by curvature in the graphitic layers.
SAMOCHÓD SPORTOWY DUOMOTO NAPĘDZANY DWOMA SILNIKAMI SPALINOWYMI
- Stanisław Taryma
- Grzegorz Ronowski
- Krzysztof Brzozowski
- Łukasz Lichota
- Marcin Miotk
- Paweł Miodoński
2018 Pełny tekst Autobusy. Technika, Eksploatacja, Systemy Transportowe
Przedstawiono zaprojektowany i zbudowany przez zespół czterech dyplomantów Wydziału Mechanicznego Politechniki Gdańskiej samochód sportowy napędzany dwoma silnikami. Jeden z nich umieszczono z przodu pojazdu. Przekazuje on moment obrotowy na koła osi przedniej poprzez zespolony układ napędowy. Drugi silnik, usytuowany ztyłu pojazdu, w identyczny sposób przekazuje moment napędowy na koła osi tylnej. Samochód nazwany Duomoto powstał na bazie dwóch Volkswagenów Golfów GT. Poddano go badaniom drogo-wym. Wyniki badań oraz wnioski zamieszczono w niniejszym artykule.
Sample preparation and recent trends in volatolomics for diagnosing gastrointestinal diseases
- Tomasz Majchrzak
- Wojciech Wojnowski
- Grażyna Piotrowicz
- Jacek Gębicki
- Jacek Namieśnik
2018 TRAC-TRENDS IN ANALYTICAL CHEMISTRY
The analysis of the human volatilome can be successfully used for rapid and non-invasive diagnostics of gastrointestinal diseases. However, the introduction of techniques based on detection of volatiles is limited, among other factors, by difficulties which arise during the sampling stage and instrumental analysis. The aim of this article was to review and discuss medical and analytical literature on the analysis of volatiles in diagnostics of gastrointestinal disorders and to elaborate on technical aspects of sampling and analysis of volatile organic compounds in this context. The easily overlooked technical aspects of the sampling and analysis of volatiles can have a significant impact on the outcome of the classification. In order to introduce headspace analysis into clinical practise, it is necessary to standardise upon the best available techniques and to introduce external validation of the results.
Sample preparation procedure using extraction and derivatization of carboxylic acids from aqueous samples by means of deep eutectic solvents for gas chromatographic-mass spectrometric analysis
- Patrycja Makoś
- Andre Fernandes
- Andrzej Przyjazny
- Grzegorz Boczkaj
2018 Pełny tekst JOURNAL OF CHROMATOGRAPHY A
The paper presents a new procedure for the determination of organic acids in a complex aqueous matrixusing ultrasound-assisted dispersive liquid–liquid microextraction followed by injection port derivati-zation and GC–MS analysis. A deep eutectic solvent (choline chloride: 4-methylphenol in a 1:2 mol ratio)was used both as an extracting solvent and as a derivatizing agent to yield ion pairs which were next con-verted to methyl esters of organic acids in a hot GC injection port. The procedure was optimized in termsof selection of a deep eutectic solvent, disperser solvent, and the ratio of their volumes, pH, salting outeffect, extraction time, injection port temperature and time of opening the split valve. The developed pro-cedure is characterized by low LOD (1.7–8.3 ␮g/L) and LOQ (5.1–25 ␮g/L) values, good repeatability (RSDranging from 4.0 to 6.7%), good recoveries for most of the studied analyte (81,5–106%) and a wide linearrange. The procedure was used for the determination of carboxylic acids in real efﬂuents from the pro-duction of petroleum bitumens. A total of ten analytes at concentrations ranging from 0.33 to 43.3 ␮g/mLwere identiﬁed and determined in the efﬂuents before and after chemical treatment. The study revealedthat in efﬂuents treated by hydrodynamic cavitation an increase in concentration of benzoic acid andrelated compounds was observed.
Sample Rate Conversion Based on Frequency Response Masking Filter
- Marek Blok
2018 Pełny tekst
The sample rate conversion with high resampling ratios requires low-pass digital filters with very narrow transition band which results in high computational complexity and makes filter design problematic. Therefore in this work we propose to use the FRM method, which breaks the filter with a narrow transition band into a group of filters with reduced design requirements. These decreases the number of non-zero coefficients and as a result the use of the FRM filter reduces the computational complexity of the resampler.
Sankcje w prawie upadłościowym w działaniu
- Sylwia Morawska
- Błażej Prusak
- Przemysław Banasik
2018
W rozdziale zaprezentowano rodzaje sankcji stosowanych przez sądy w przypadku nieprzestrzegania przez niewypłacalnych przedsiębiorców regulacji zawartych w prawie upadłościowym. Przeprowadzono analizę związku pomiędzy liczbą oddalonych wniosków o ogłoszenie upadłości z powodu "ubóstwa" masy upadłościowej i stosowanych przez sądy sankcji.
Scenarios in regional planning – theory and practice in Poland
- Jacek Sołtys
2018 Pełny tekst European Spatial Research and Policy
Abstract. It is important to recognise future conditions in planning because it primes future actions. Scenarios are useful prognostic tools, especially when the social and institutional behaviour plays a crucial role. The aims of the paper are: (1) to indicate the roles and the place of scenarios in the strategic plan building process; (2) to analyse and evaluate the application of scenarios in regional planning in Poland; (3) to transpose the research results on scenarios in local planning for their application in regional planning. There are a few documents in which scenarios are applied: three strategies for regional development and two spatial development plans for regions. The author analysed the scenarios in all of those documents and offered some recommendations transposing the effects of previous research from local to regional planning.
Scheduling of unit-length jobs with cubic incompatibility graphs on three uniform machines
- Hanna Furmańczyk
- Marek Kubale
2018 Pełny tekst DISCRETE APPLIED MATHEMATICS
We consider the problem of scheduling n identical jobs on 3 uniform machines with speeds s1, s2, and s3 to minimize the schedule length. We assume that jobs are subject to some kind of mutual exclusion constraints, modeled by a cubic incompatibility graph. We how that if the graph is 2-chromatic then the problem can be solved in O(n^2) time. If the graph is 3-chromatic, the problem becomes NP-hard even if s1>s2=s3.
Schronienie – poszukiwanie formuły dla domu wpisanego w relacje środowiskowe
- Agnieszka Kurkowska
2018 Pełny tekst
Konieczność schronienia i potrzeba zamieszkiwania wymagają przestrzeni, które współcześnie zazwyczaj zabezpieczają obiekty architektoniczne. Jednak często zauważamy niedobory wartości w przestrzeni zamieszkiwania. Pomysłem zaradczym w tej sytuacji jest powrót do punktu wyjścia. Do zapewnienia schronienia. Jeśli będzie ono wpisane w relacje środowiskowe i ukształtowane w zgodzie z potrzebą zachowania ciągłości kulturowej, ma szansę stać się początkiem prawdziwego Domu, punktem wyjścia dla jego kreacji w złożonym procesie zamieszkiwania. Sytuację komplikuje podjęcie próby zmiany istniejących obiektów mieszkalnych wielorodzinnych, tworzących popularne w Polsce „blokowiskach”, w prawdziwe Domy. Autorskim zamysłem jest posłużenie się ideowymi rzeźbami architektonicznymi jako narzędziami przekazu określonych treści i intencji wspomagających wzmocnienie poczucia tożsamości z zamieszkiwanym regionem poprzez przywołanie rzeczywistych, ale często zapomnianych konotacji. Refleksje i doświadczenia związane z odbiorem obiektów współtworzących cykl pt. „Schronienia”, zaprezentowany na gdańskiej Zaspie w ramach Festiwalu Artystycznego w 2016 roku, miały w zamyśle kierunkować możliwe i konieczne zarazem działania zaradcze w istniejącej niepełnowartościowej przestrzeni. Ukazanie potencjału wprowadzenia harmonijnych relacji pomiędzy formą kulturową i elementami przyrodniczymi, stanowi wskazówkę dla poszukiwania lub wzmocnienia relacji istniejących budynków ze środowiskiem, w którym żyją ich mieszkańcy. Przedstawione szkice, fotografie i rzeźby unaoczniają siłę wartości, które pochodzą z poszukiwanego porozumienia pomiędzy architekturą a przyrodą. Obrazy i obiekty przeniesione z nieodległych Kaszub w realia osiedla mieszkaniowego przypominają o potencjalnym źródle poszukiwanych wartości.
Sczepność warstw asfaltowych w wielowarstwowych układach nawierzchni drogowych
- Piotr Jaskuła
2018
Sczepność warstw asfaltowych w konstrukcji nawierzchni drogowej ma kluczowe znaczenie dla zachowania się nawierzchni pod obciążeniem od pojazdów samochodowych. W tym celu przeprowadzono badania sczepności międzywarstwowej w schemacie Leutnera przy obciążeniu monotonicznym dla określenia maksymalnej siły ścinającej, przemieszczenia ścinającego, wytrzymałości ścinania, sztywności ścinania, energii ścinania. Dla wybranych przypadków przeprowadzono również badania pod obciążeniem cyklicznym w celu określenia charakterystyk zmęczeniowych połączeń międzywarstwowych w stanie kontrolowanego naprężenia. Stwierdzono, że siła połączenia międzywarstwowego jest zależna od wielu czynników, spośród których istotnie decydujące są: rodzaj i ilość emulsji asfaltowej zastosowanej do skropienia międzywarstwowego, rodzaj asfaltu, z jakiego wyprodukowano emulsję, różnica uziarnienia sąsiadujących warstw oraz skuteczność zagęszczenia warstw sąsiadujących. Na odcinku doświadczalnym wykonano w skali rzeczywistej symulację różnych poziomów sczepności międzywarstwowej oraz badano ich wpływ na zachowanie się konstrukcji nawierzchni za pomocą urządzenia FWD. Osiągnięty na niektórych sekcjach odcinka doświadczalnego brak powiązania międzywarstwowego przyczynił się do obniżenia nośności nawierzchni. W miejscach tych wystąpiły zwiększone ugięcia w stosunku do miejsc, gdzie występowała pełna sczepność międzywarstwowa. W monografii dokonano także oceny wyników badań sczepności międzywarstwowej, które uzyskano podczas realizacji 74 inwestycji drogowych na głównej sieci dróg krajowych (w tym autostrad i dróg ekspresowych) w latach 2012–2013. Stwierdzono, że na drogach najwyższego standardu technicznego, jak również najwyższego poziomu kontroli jakości uzyskuje się bardzo dobrą sczepność pomiędzy warstwami asfaltowymi. W pracy przedstawiono też wyniki analiz obliczeniowych wykonanych przy zastosowaniu modelu wielowarstwowej półprzestrzeni sprężystej, które dotyczyły wpływu braku sczepności międzywarstwowej i ewentualnego jego umiejscowienia na ugięcia i trwałość nawierzchni. Za pomocą metody elementów skończonych przeprowadzono również symulacje zachowania się nawierzchni z użyciem różnych modeli opisujących kontakt między warstwami, w tym między innymi z uwzględnieniem tarcia i kohezji w styku warstw. Wskazano modele do dalszego wykorzystania i zweryfikowano modelowanie analityczne z pomiarami ugięć nawierzchni w terenie.
Seafloor Characterisation Using Underwater Acoustic Devices
- Zbigniew Łubniewski
- Andrzej Stepnowski
2018 IEEE WIRELESS COMMUNICATIONS LETTERS
The problem of seafloor characterisation is important in the context of management as well as investigation and protection of the marine environment. In the first part of the paper, a review of underwater acoustic technology and methodology used in seafloor characterisation is presented. It consists of the techniques based on the use of singlebeam echosounders and seismic sources, along with those developed for the use of sidescan and multibeam sonar systems. In the second part, the review is followed by a description of the combined approach to seafloor characterisation developed by the authors. It is based on extraction of three types of information from multibeam sonar recordings, namely: 1) the sonar image of seabed surface, 2) the point cloud describing seabed surface shape, 3) the set of echo envelopes corresponding to particular sonar beams. Then the seafloor classification is performed using the set of parameters (descriptors) which are calculated on the basis of 3 types of sonar data mentioned above. The proposed approach has been tested using field sonar data recordings in the water region of the Southern Baltic Sea. In this region, four sites differing by seabed type were investigated.
Seasonal changes of mercury speciation in the coastal sediments
- Jacek Bełdowski
- Marta Szubska
- Magdalena Bełdowska
- Katarzyna Jankowska
- Ewa Kotlarska
- Bożena Graca
2018 Pełny tekst JOURNAL OF SOILS AND SEDIMENTS
Purpose Mercury speciation in sediments is linked to environmental conditions and processes. Domination of particular mercury species depends on its source, displays considerable seasonal behavior, and may be further modified due to oxygen levels, icing conditions, or the input of fresh organic matter. The purpose of this study was to examine the coastal area of the Gulf of Gdańsk in terms of mercury contamination and the influence of seasonal environmental changes on its speciation. Materials and methods In three highly dynamic coastal sites, mercury speciation in sediments was studied in relation to other environmental parameters (redox conditions, organic matter concentration, bacteria abundance, etc.). Sediment and water samples were collected monthly during a 3-year study. Sequential extraction of sediments was used for identification of four inorganic mercury species: dissolved, bound with fulvic and humic acids, mercury sulfide, and residual fraction. Cold vapor atomic fluorescence spectrometry (CV-AFS) was used for extracts and liquid sample analysis. Total mercury in sediments was measured with atomic absorption spectrometry (AAS). Changes in salinity were analyzed by measurements of chloride and sulfate ion concentrations using ion chromatography. Bacteria number and biomass were measured by direct counting using epifluorescence microscopy. Results and discussion Seasonal changes in mercury speciation were observed at all sites and attributed to different processes. Labile mercury fraction contribution varied from 0 to 80%. The speciation patterns varied locally as the stations selected for the study are diversified in terms of anthropogenic impact, water dynamics, and output from land. Mercury concentrations at all stations fluctuated during phytoplankton blooms, icing of marine waters, precipitation, or increased surface runoff from the land. In this local scale, the global climate changes are visible already as environmental conditions in studied area changed in comparison to elder research. Conclusions Obtained results suggest that although mercury emissions to the environment have decreased in recent years, local weather conditions, which may be intensified by climate change, seriously affect the bioavailability of past mercury deposits in coastal sediments.
Seawater intrusion due to pumping mitigated by natural freshwater flux: a case study in Władysławowo, northern Poland
- Małgorzata Pruszkowska-Caceres
- Adam Szymkiewicz
- Beata Jaworska-Szulc
- Maria Przewłócka
- Anna Gumuła-Kawęcka
- Dawid Potrykus
2018
The paper presents a case study of seawater intrusion into a coastal aquifer, caused by a groundwater intake located close to the seashore in Władysławowo, northern Poland. Evolution of the basic hydrogeochemical parameters for the 50-year period from 1964 to 2014 indicates progressing encroachment of saline seawater into the aquifer. However, the spatial pattern of salinity was influenced by the variability of hydraulic gradient in fresh water discharging from aquifer to the sea. As a consequence, significant changes in salinity occurred in the directions both perpendicular and parallel to the coastline.
Second-order Stark effect and polarizability of a relativistic two-dimensional hydrogenlike atom in the ground state
- Radosław Szmytkowski
2018 Pełny tekst PHYSICAL REVIEW A
The second-order Stark effect for a planar Dirac one-electron atom in the ground state is analyzed within the framework of the Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian series expansion of the generalized Dirac-Coulomb Green's function. A closed-form analytical expression for the static dipole polarizability of that system is found. The formula involves the generalized hypergeometric function ${}_{3}F_{2}$ with the unit argument. Numerical values of the polarizabilities for relativistic planar hydrogenic atoms with atomic numbers $1\leq Z\leq 68$ are provided in a tabular form. A simple formula for the polarizability of a nonrelativistic two-dimensional hydrogenic atom, reported previously by several other authors, is recovered from our result in the nonrelativistic limit.
Security of export transactions in the offer of leading banks on the Polish market
- Robert Sterniński
2018
The following article presents the so-called conditioned payment methods, i.e. instruments for securing export transactions, such as letter of credit, documentary collection, bank guarantees, factoring and forfaiting. The characteristics of each particular method are presented as well as the transactions using them are described. In the following paper, the author included also the leading Polish banks, which offer the above- mentioned payments and security instruments. The next section of the article includes the amount of fees for the exporter for the use of the bank's transaction security together with the comparison of particular offers. The amount of fees in individual banks varies, but these discrepancies, when compared to the value of a given transaction, do not appear to be of key importance for the operations of enterprises. Therefore, in order to eliminate the risk related to the lack of payment for the delivered goods, the author of this article recommends to all exporters the use of transaction security, and when choosing a bank in the first place, check its reputation and experience in this type of activity.
SELECTED COMBINED POWER SYSTEMS CONSISTED OF SELFIGNITION ENGINE AND STEAM TURBINE
- Wojciech Olszewski
- Marek Dzida
2018 Pełny tekst Polish Maritime Research
This paper presents optimization of selected combined diesel engine-steam turbine systems. Two systems: the system combined with waste heat one-pressure boiler only and its version containing additionally low-pressure boiler proper feeding degasifier and the system of two-pressure cycle, were taken into considerations. Their surplus values of power output and efficiency associated with utilization of waste heat contained in piston engine exhaust gas were compared to each other. For the considerations two high-power low-speed engines were taken into account. The main engines of comparable power of about 54 MW produced by Wartsila and MAN Diesel & Turbo firms, were selected.
Selected Methods for the Chemical Phosphorylation and Thiophosphorylation of Phenols
- Witold Kozak
- Janusz Rachoń
- Mateusz Daśko
- Sebastian Demkowicz
2018 Asian Journal of Organic Chemistry
This Focus Review gathers together a selection of methods for the chemical phosphorylation of phenols that employ three‐ and four‐coordinate phosphorus compounds. Phosphorylated scaffolds can exhibit enhanced properties compared to their non‐phosphorylated analogues, such as increased biological activity and increased/decreased solubility; as such, phosphorus compounds have gained more and more interest in organic and medicinal chemistry. Phosphate esters are valuable intermediates in drug synthesis and, from this point of view, a knowledge of effective and selective methods for chemical phosphorylation is essential. Furthermore, phosphates form the basis of a large number of herbicides, insecticides, and nerve agents and they can act as flame retardants and plasticizers to protect or enhance the properties of various materials, such as textiles, furniture, or plastics.
Selected problems of sensitivity and reliability of a jack-up platform
- Bogdan Rozmarynowski
- Tomasz Mikulski
2018 Pełny tekst Polish Maritime Research
The paper deals with sensitivity and reliability applications to numerical studies of an off-shore platform model. Structural parameters and sea conditions are referred to the Baltic jack-up drilling platform. The study aims at the influence of particular basic variables on static and dynamic response as well as the probability of failure due to water waves and wind loads. The paper presents the sensitivity approach to a generalized eigenvalue problem and evaluation of the performance functions. The first order time-invariant problems of structural reliability analysis are under concern.
Selection of AHI + SC Hybrid Storage Based on Mathematical Models and Load Variation Characteristics
- Monika Liedke
- Łowiec Eugeniusz
- Wojciech Matelski
- Leszek Wolski
- Ryszard Strzelecki
2018 Pełny tekst Przegląd Elektrotechniczny
The article deals with the design of a hybrid storage consisting of Aqueous Hybrid Ion battery (AHI) and supercapacitor (SC) modules. The selection of components is based on the knowledge of the load profile of the storage and the AHI battery and supercapacitor models. The paper presents the method of selecting components of the storage made of AHI batteries and supercapacitor modules The article includes an example of the hybrid storage design intended for the supply of household electric appliances.