2018 - Repozytorium publikacji - Politechnika Gdańska

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Decomposition of Acoustic and Entropy Modes in a Non-Isothermal Gas Affected by a Mass Force
- Anna Perelomova
- Sergey Leble
2018 Pełny tekst Archives of Acoustics
Diagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant mass force. The diagnostic relations link acoustic and entropy modes, and are independent of time. Hence, they provide an ability to decompose the total vector of perturbations into acoustic and non-acoustic (entropy) parts, and to establish the distribution of energy between the sound and entropy modes, uniquely at any instant. The total energy of a flow is hence determined in its parts which are connected with acoustic and entropy modes. The examples presented in this work consider the equilibrium temperature of a gas, which linearly depends on the vertical coordinate. Individual profiles of acoustic and entropy parts for some impulses are illustrated with plots.
Decreasing CO2 Emissions By Reducing Tire Rolling Resistance
- Jerzy Ejsmont
- Beata Świeczko-Żurek
2018 Pełny tekst
The first motor vehicle was built by Nicolas Cugnot almost 250 years ago and since then there has been a continuous process of motor vehicles’ improvements, as well as development of new road pavements. The fuel crisis of the 70s of the 20th century made it clear to vehicle builders that measures should be taken to reduce vehicle fuel consumption and it contributed to an increased interest in electric vehicles. Although significant progress has already been made in reducing fuel consumption by internal combustion vehicles, at the turn of the 20th and 21st centuries, a new challenge has arisen, namely the need to reduce CO2 emissions. To achieve this, both the need to build more ecological friendly sources of propulsion and to significantly reduce the vehicle's resistance, have to be addressed. This paper deals with one of the most important sources of vehicle resistance - the rolling resistance. Rolling resistance is a phenomenon that occurs at the tire's interface with the roadway and depends on the tire construction, pavement parameters, vehicle operating parameters and atmospheric conditions. The paper presents how big is the influence of rolling resistance on overall energy consumption of road vehicles and how to evaluate rolling resistance, especially in real road conditions. Rolling resistance is very difficult to measure, so it is common to use simplified methods, which do not always provide representative results. The paper presents an overview of rolling resistance research methods, their advantages and disadvantages and the impact of the most important parameters of tires, pavement and traffic conditions on tire rolling resistance. Special attention is given to the problem of implementing proper procedures during road measurements of rolling resistance as road measurements are not standardized yet, despite the fact that, if performed correctly, they may give the most representative and precise results leading to improvements of pavements and tires. The results of rolling resistance tests conducted on rubber modified asphalt and on porous surfaces are also presented.
Deep CNN based decision support system for detection and assessing the stage of diabetic retinopathy
- Arkadiusz Kwasigroch
- Bartlomiej Jarzembinski
- Michal Grochowski
2018
The diabetic retinopathy is a disease caused by long-standing diabetes. Lack of effective treatment can lead to vision impairment and even irreversible blindness. The disease can be diagnosed by examining digital color fundus photographs of retina. In this paper we propose deep learning approach to automated diabetic retinopathy screening. Deep convolutional neural networks (CNN) - the most popular kind of deep learning algorithms - enjoyed great success in the field of image analysis and recognition. Therefore, we leverage CNN networks to diagnose the diabetic retinopathy and its current stage, based on analysis of the photographs of retina. The utilized models were trained using dataset containing over 88000 retina photographs, labeled by specialist clinicians. To enhance the performance of the system, we proposed a special class coding technique that enabled to include the information about value of difference between predicted score and target score into the objective function being minimized during the neural networks training. To evaluate classification ability of employed models we used standard accuracy metrics and quadratic weighted Kappa score that is calculated between the predicted scores and scores provided in the dataset. The best tested model achieved an accuracy of about 82% in detecting the retinopathy and 51% in assessing its stage. Moreover, system obtained decent Kappa score equal 0.776. Achieved results showed that deep learning algorithms can be successfully employed to solve this very hard to analyze problem.
Deformation Analysis of a Composite Bridge during Proof Loading Using Point Cloud Processing
- Patryk Ziółkowski
- Jakub Szulwic
- Mikołaj Miśkiewicz
2018 Pełny tekst SENSORS
Remote sensing in structural diagnostics has recently been gaining attention. These techniques allow the creation of three-dimensional projections of the measured objects, and are relatively easy to use. One of the most popular branches of remote sensing is terrestrial laser scanning. Laser scanners are fast and efficient, gathering up to one million points per second. However, the weakness of terrestrial laser scanning is the troublesome processing of point clouds. Currently, many studies deal with the subject of point cloud processing in various areas, but it seems that there are not many clear procedures that we can use in practice, which indicates that point cloud processing is one of the biggest challenges of this issue. To tackle that challenge we propose a general framework for studying the structural deformations of bridges. We performed an advanced object shape analysis of a composite foot-bridge, which is subject to spatial deformations during the proof loading process. The added value of this work is the comprehensive procedure for bridge evaluation, and adaptation of the spheres translation method procedure for use in bridge engineering. The aforementioned method is accurate for the study of structural element deformation under monotonic load. The study also includes a comparative analysis between results from the spheres translation method, a total station, and a deflectometer. The results are characterized by a high degree of convergence and reveal the highly complex state of deformation more clearly than can be concluded from other measurement methods, proving that laser scanning is a good method for examining bridge structures with several competitive advantages over mainstream measurement methods.
Degradation kinetics and mechanism of pentoxifylline by ultraviolet activated peroxydisulfate
- Beata Kamińska
- Koleta Hemine
- Anna Skwierawska
- Katarzyna Kozłowska-Tylingo
2018 Pełny tekst RSC Advances
Degradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water. The treatment was more favorable over direct photolysis or peroxydisulfate oxidation alone. The effects of various parameters, including different dosage of oxidant agent, PTX concentration, initial solution pH levels, and the presence of inorganic ions like chloride, nitrate and carbonate have been evaluated. The rate of PTX decomposition depends on the oxidant agent dose. The highest degradation was determined at pH 10.5, which can be explained by the generation of additional hydroxyl radicals (HOc) in the reaction between sulfate radicals and hydroxide ions. The presence of inorganic ions, especially the carbonate ions quench valuable sulfate radicals and have successfully retarded the PTX decomposition. Six PTX oxidation products were identified using UPLC-QTOF-MS for trials in a basic environment. The main degradation product (3,7-dimethyl-6-(5- oxohexyloxy)-3,7-dihydro-2H-purin-2-one) was isolated by column chromatography and identified by 1HNMR and LC MS analyzes.
Degradation of protective coatings in steel chimneys of flue gas desulfurisation system
- Stefan Krakowiak
- Kazimierz Darowicki
2018 PROGRESS IN ORGANIC COATINGS
This paper presents problems associated with corrosion of steel stacks and changes in philosophy of corrosion protection when implemented into flue gas desulphurization systems. In-situ tests were taken by means of electrochemical impedance spectroscopy at the stack which discharges flue gas before wet lime/limestone desulphurization. A very quick electrolyte absorption by the spherical infill vinylester coating was found using the electrochemical impedance spectroscopy. An analysis of destruction shows a joint effect of mechanical and corrosion factors on the poor resistance of the coating. The poor resistance of the coating is also connected with the method of chimney construction and coating application.
Degradation of the Concrete Railway Track Bed Located in the Vicinity of the Loading Wharf
- Maciej Niedostatkiewicz
2018 Pełny tekst Polish Maritime Research
The following article describes the damages of the concrete railway track bed at the place of unloading petroleum products located in the immediate vicinity of the cargo berth. The concrete of the track bed has been a subject to degradation as a result of many years of exploitation resulting, inter alia, in its cyclical flooding of petroleum products during the unloading and loading of rail tankers. Repairs carried out in the previous period involving the reprofiling of the top part of the board proved to be ineffective. Methods of repairing existing damages have been proposed. Due to the need to limit the time of excluding the track from operation, the repair works were divided into two stages - ad hoc, intended for urgent implementation, and target, to be carried out as a major overhaul.
Dekalog internacjonalizacji szkolnictwa wyższego w Polsce
- Karolina Wysocka
- Krzysztof Leja
2018 Pełny tekst e-mentor
Rozwój internacjonalizacji, obok doskonalenia zarządzania i dywersyfikacji misji, jest jednym z najważniejszych zadań stojących przed współczesnymi polskimi szkołami wyższymi. Dostrzeżono to w projekcie ustawy Prawo o szkolnictwie wyższym i nauce. W literaturze światowej można znaleźć liczne opracowania naukowe dotyczące internacjonalizacji kształcenia i badań naukowych. Brakuje natomiast publikacji, podejmujących tematykę implementacji szeroko pojętej internacjonalizacji w obszarze uczelnianej administracji. Autorzy podjęli próbę wypełnienia tej luki poznawczej, wskazując dziesięć głównych obszarów decydujących o jakości obsługi administracyjnej procesu internacjonalizacji, nazywając je dekalogiem internacjonalizacji ze względu na ich istotność. W artykule pokrótce omówiono każdy z tych obszarów. W podsumowaniu stwierdzono, że internacjonalizacja w różnym stopniu dotyczy wszystkich obszarów funkcjonowania uczelni, ale także, że jako zjawisko kulturowe jest nierozerwalnie związana z tradycją akademicką.
DELIMITACJA OBSZARU REWITALIZACJI NA PRZYKŁADZIE LOKALNEGO PROGRAMU REWITALIZACJI MIASTA WEJHEROWA
- Piotr Lorens
- Sławomir Ledwoń
2018 Pełny tekst Studia Komitetu Przestrzennego Zagospodarowania Kraju PAN
W ramach artykułu przedstawiono sposób pracy oraz zakres delimitacji obszaru zdegradowanego i obszaru rewitalizacji dla Miasta Wejherowa. Materiał ten służyć może jako punkt odniesienia do innych tego typu opracowań oraz do porównań o charakterze teoretycznym
Delivery of Ancillary Services in Distribution Power Systems
- Paweł Bućko
- Marcin Jaskólski
- Zbigniew Lubośny
- Jacek Klucznik
- Krzysztof Dobrzyński
2018
One of the technical and organizational challenges the power system faces in deregulated market conditions is to organize an ancillary services market. The growing share of distributed generation of variable (intermittent) energy sources and a change in the market position of consumers, causes the demand for distributed delivery of ancillary services. For this purpose, it is sought to use the ability of the regulatory measures: dispersed generators, consumers, prosumers, and energy storage systems. The most important attempts discussed in the paper were: organizational solutions, i.e. creating balancing groups or virtual power plants; the use of response actions of customers, e.g. in the context of Demand Side Management or Demand Side Response and the search for effective energy storage technologies. Additionally, the role of the Distribution System Operator as the coordinator of ancillary services in a local network was discussed.
DenCity – a Pan-European Future
- Izabela Mironowicz
2018 disP
The paper considers interrelations between density and quality of life in European cities.
Dependence between Ionic Liquid Structure and Mechanism of Visible-Light-Induced Activity of TiO2 Obtained by Ionic-Liquid-Assisted Solvothermal Synthesis
- Marta Paszkiewicz-Gawron
- Marta Długokęcka
- Wojciech Lisowski
- Maria Paganini
- Elio Giamello
- Tomasz Klimczuk
- Monika Paszkiewicz
- Ewelina Grabowska
- Adriana Zaleska-Medynska
- Justyna Łuczak
2018 ACS Sustainable Chemistry & Engineering
Because of the tremendous structural diversityof ionic liquids (ILs), simple transfer of observations performed for one IL used for IL-TiO2 preparation on different samples is not possible. Therefore, four ionic liquids, all containing distinct nitrogen-bearing organic cations (pyridinium, pyrrolidinium, ammonium, imidazolium), were used for the first time for the preparation of IL-TiO2 composites. The role of the individual IL cation in the synthesis of TiO2 microspheres, as well as the effect of the IL structure on the mechanism of the visible-light (Vis)-induced photoactivity of IL-TiO2 was presented and discussed in regard to structure, morphology, absorption properties, elemental composition, and reactive species involved in the photocatalytic reaction of phenol degradation. The successful modification of the TiO2 with organic IL species including possible interactions between IL and TiO2 surface, as well as the TiO2 matrix (doping with N), were confirmed. The sample that exhibited the highest photoactivity under Vis irradiation (58%) was TiO2 prepared in a presence of 1-butylpyridinium chloride with a IL:precursor molar ratio of 1:3. For this sample, the highest partial decomposition of cationic species of IL was observed resulting in interaction of N atoms with deeper sites of TiO2 (Ti-Nx) as well as the highest surface defects in a form of Ti3+. The superoxide radical species O2• − were found to be main active species responsible for high efficiency of degradation under Vis irradiation.
Depth Determination Accuracy of the Modified Prony Method in a Swath Mapping Application
- Piotr Grall
- Jacek Marszal
2018
This article presents the performance of the modified Prony method in a swath mapping application. Depth determination accuracy is assessed by processing raw signal acquired by an EdgeTech 6205 swath bathymetry system over flat seafloor. An updated version of the method, proposed previously by the authors, is used to determine the number of signal echoes. The number of signal echoes is essential for performing the low-rank approximation of the data matrix in the modified Prony method. The achieved accuracy results are also compared to the results of other methods applied to the same signal and International Hydrographic Organization standards.
Derywatyzacja in situ w połączeniu z techniką DLLME-oznaczanie amin biogennych w winach owocowych
- Justyna Płotka-Wasylka
- Ewa Kłodzińska
- Jacek Namieśnik
2018 Pełny tekst Analityka: Nauka i Praktyka
W literaturze można znaleźć potwierdzenie dla tezy, że miniaturyzacja oraz automatyzacja to kluczowe elementy, które powinny być brane pod uwagę przy optymalizacji tych procedur analitycznych, w których występuje etap derywatyzacji analitów, jeśli mają być one zaliczone do grupy tzw. zielonych metodyk analitycznych. Rezultatem zastosowania takiego podejścia jest zmniejszenie ilości zużytych odczynników i tym samym, zmniejszenie ilości wytworzonych odpadów. Jedną z technik mikroekstrakcji, która spełnia powyższe wymogi jest dyspersyjna mikroekstrakcja w układzie ciecz-ciecz, która w połączeniu z techniką GC-MS stanowi dobre rozwiązanie do oznaczania amin biogennych w próbkach o skomplikowanym składzie matrycy, np. winie.
Design and investigations of the ethanol microturbine
- Krzysztof Kosowski
- Marian Piwowarski
- Robert Stępień
- Wojciech Włodarski
2018 Pełny tekst Archives of Thermodynamics
The paper presents the results of the design analysis and experimental investigations of the microturbine set consisting of the microturbine with partial admission and permanent magnet generator. The microturbine was designed for operation with the vapour of ethanol as a working fluid. Microturbine unit was tested for different parameters of the working fluid and varying the electrical load. The examples and the comparison between experiment results and numerical simulations are shown and discussed in the paper.
Design and optimization of a novel miniaturized low-profile circularly polarized wide-slot antenna
- Ubaid Ullah
- Sławomir Kozieł
2018 JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS
This paper presents a novel structure of a compact circularly polarized (CP) antenna. CP is obtained using a parasitic quasi-rectangular strip placed coplanar to the feedline. A ground plane perturbation combined with the asymmetric geometry of the coplanar waveguide ground planes is utilized to excite additional CP modes. All antenna dimensions are rigorously optimized to achieve the best possible performance in terms of the impedance and axial ratio bandwidth (ARBW). The size of the proposed antenna is only 24.7 × 25 mm2. The antenna performance is validated experimentally. A close agreement between simulation and experimental results is observed. A wide impedance bandwidth of 42.6% (3.93–6.06 GHz) and ARBW of 42% (3.96–6.03 GHz) is with 98.5% bandwidth overlap between |S11| and AR is achieved. The average realized gain of the antenna throughout the operating frequency is 3.4 dBic. Left-hand circular polarization radiation is achieved in the +z-direction.
Design of a continuous intra-oral distraction device for mandibular bone
- Karolina Wszelak
- Mateusz Łabul
2018 Pełny tekst International Journal of New Technology and Research
In this paper we present example of a specific device used for distraction osteogenesis. Distraction osteogenesis (also called callus distraction, collotasis or osteodistraction) is a surgical process for reconstructing bone deformities or lengthening bones.
Design of a Multidomain IMS/NGN Service Stratum
- Sylwester Kaczmarek
- Maciej Sac
2018
The paper continues our research concerning the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). A design algorithm for a multidomain IMS/NGN service stratum is proposed, which calculates the necessary CSCF servers CPU message processing times and link bandwidths with respect to the given maximum values of mean call set-up delays E(CSD) and mean call disengagement delays E(CDD) for all types of successful call scenarios. These delays are standardized call processing performance parameters, which are very important for satisfaction of users and overall success of the IMS/NGN concept. In the paper a block diagram of the algorithm and details regarding its operation are described. Using the implemented algorithm several multidomain IMS/NGN service stratum designs are performed for different data sets and their results are discussed.
Design optimization of novel compact circular polarization antenna
- Sławomir Kozieł
- Adrian Bekasiewicz
2018 Pełny tekst
The paper describes a structure and a design optimization procedure of a miniaturized circular polarization antenna with elliptical ground plane slots and feed line with stepped-impedance stubs. Constrained optimization of all antenna parameters is executed in order to explicitly reduce the antenna size while maintaining required impedance axial ratio bandwidth of 5 GHz to 7 GHz at the same time. The size of the optimized antenna is only 16.2 mm × 16.7 mm (footprint of 271 mm2). At the same time, the electrical and field properties of the structure are competitive for state-of-the-art designs as indicated by the comparison provided in the paper.
Design, Synthesis, and Enzymatic Evaluation of Novel ZnO Quantum Dot-Based Assay for Detection of Proteinase 3 Activity
- Jadwiga Popow-Stellmaszyk
- Beata Bajorowicz
- Anna Malankowska
- Magdalena Wysocka
- Tomasz Klimczuk
- Adriana Zaleska-Medynska
- Adam Lesner
2018 BIOCONJUGATE CHEMISTRY
Herein, the synthesis and application of functionalized quantum dot-based protease probes is described. Such probes are composed of nontoxic ZnO nanocrystals decorated by amino groups followed by linker and labeled peptide attachment. Spherical NH2-terminated ZnO quantum dots (QDs) with the average size ranging from 4 to 8 nm and strong emission centered at 530 nm were prepared using the sol−gel method. The fluorescence of ZnO QDs was quenched by the BHQ1 moiety present on the N-terminal amino group of the peptide. The enzymatic cleavage of the peptide mediated by the proteinase 3 (PR3) bond resulted in an increase in the QD probe fluorescence. This observation was verified using both model and biological systems; and the picomolar detection limit was found to be more than 30 times lower than that of the previously reported internally quenched peptide (a decrease in detection limit from 43 to 1.3 pmol was observed).