2016 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2016

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Analysis of wave propagation in a bolted steel joint
- Rafał Kędra
- Magdalena Rucka
2016
The paper presents results of numerical and experimental investigations of elastic wave propagation in a bolted single-lap joint. The research was carried out for both symmetric and antisymmetric Lamb wave modes. In experimental studies the PZT transducers were used to excite and register wave propagation signals. The controlled value of the torque during measurements was ensured by the use of high precision torque wrenches. Numerical model of the joint was developed by the finite element method using commercial software Abaqus. The analysis took into account varying contact conditions between the connected parts of the joint depending on the value of the bolt torque. Both experimental and numerical results showed the influence of the value of the pretension force on the amplitude and phase shifts of registered signals.
Analysis the Parameters of the Adaptive Controller for Quality Control of Dissolved Oxygen Concentration
- Robert Piotrowski
- Karol Błaszkiewicz
- Kazimierz Duzinkiewicz
2016 Information Technology and Control
The wastewater treatment plant can be considered a dynamic large scale complex system, in which the most important control parameter is the dissolved oxygen concentration in the aerobic zone. The air is supplied to this zone by the aeration system. In the paper, both the sequencing batch reactor and the aeration system are modelled and used as plant of control performed by the cascade nonlinear adaptive control system extended by the anti-windup filter. The effect of certain parameters of the adaptive controller on the quality of control is analysed. Simulation results based on real data recorded in the case study plant are included.
Analytical design method of reverse curves
- Władysław Koc
2016 Full text Przegląd Komunikacyjny
The paper deals with a new approach relating to the design of the region of railway track direction alteration adapted to Mobile Satellite Measurements technique. The method may be particularly useful in situations when both the straights of the route directions cannot be connected in an elementary way using a circular arc with transition curves; this also refers to the application of a compound curve. Thus the only solution becomes the application of two circular arcs of opposite curvature signs to the geometric system, i.e. the use of an inverse curve. The solution of the design problem takes advantage of a mathematical notation and concentrates on the determination of universal equations describing the entire geometric system. This is a sequential operation involving successive parts of the system. The presented method has been illustrated by appropriate calculation examples.
Analytical model with non-adiabatic effects for pressure drop and heat transfer during boiling and condensation flows in conventional channels and minichannels
- Dariusz Mikielewicz
- Rafał Andrzejczyk
- Blanka Jakubowska
- Jarosław Mikielewicz
2016 Full text HEAT TRANSFER ENGINEERING
In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for boiling flow and condensation flow with account of non- adiabatic effects for some recent data collected from literature. The first effect, the modification of interface shear stresses in annular flow pattern is considered through incorporation of the so called "blowing parameter". The mechanism of modification of shear stresses at the vapor-liquid interface for such case has been presented in detail in the paper. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also another influence of the wall heat flux, where it is influencing the bubble nucleation in the case of the bubbly flow pattern. As a result a modified general form of the two-phase flow multiplier, applicable both to boiling flow and condensation flow, is obtained, in which the non-adiabatic effects are clearly pronounced. Obtained model of two-phase multiplier, incorporating the non-adiabatic effects is additionally used in predictions of heat transfer coefficient.
Analytical modeling of electric drives for vehicle traction control systems
- Artur Opaliński
- Leszek Jarzębowicz
2016
Wheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five various transfer-function models including issues of digital control events timing. The aim of the paper is to compare the accuracy of the models in representing dynamics of a Permanent Magnet Synchronous Motor (PMSM) drive. Bode characteristics of the analytical models are compared to these of a reference model. The comparison is made for three commonly used cases of PMSM current sampling. Applicability of presented models has been discussed and frameworks to use specific models have been indicated.
Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
- Maciej Tankiewicz
- Jacek Namieśnik
- Wiesław Sawicki
2016 Full text TRAC-TRENDS IN ANALYTICAL CHEMISTRY
Residual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies for the determination of residual solvents in different pharmaceutical samples are reviewed to demonstrate their limitations, which form the basis of discussion about new methods. Several interesting new alternatives for sample preparation and gas chromatography (GC) separation are presented using examples from recent studies. The techniques described are direct injection, headspace analysis with different modifications and variations, liquid extraction, single-drop microextraction, and solid-phase microextraction. Various GC separation techniques are compared and new solutions to improve sensitivity and efficiency are presented.
Analytical solution of non-stationary heat conduction problem for two sliding layers with time-dependent friction conditions
- N. Belyakov
- Oleksii Nosko
2016 Full text INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
In this article we conduct an overview of various types of thermal contact conditions at the sliding interface. We formulate a problem of non-stationary heat conduction in two sliding layers with generalized thermal contact conditions allowing for dependence of the heat-generation coefficient and contact heat transfer coefficient on time. We then derive an analytical solution of the problem by constructing a special coordinate integral transform. In contrast to the commonly used transforms, e.g. Laplace or Fourier transforms, the one proposed is applicable to a product of two functions dependent on time. The solution is validated by a series of test problems with parameters corresponding to those of real tribosystems. Analysis shows an essential influence of both time-dependent heat-generation coefficient and contact heat transfer coefficient on the partition of the friction heat between the layers. The solution can be used for simulating temperature fields in sliding components with account of this influence.
Analytical studies of spectrum broadcast structures in quantum Brownian motion
- Jan Tuziemski
- Jarosław Korbicz
2016 Journal of Physics A-Mathematical and Theoretical
Spectrum broadcast structures are a new and fresh concept in the quantum-to-classical transition, introduced recently in the context of decoherence and the appearance of objective features in quantum mechanics. These are specific quantum state structures, responsible for the objectivization of the decohered state of a system. Recently, they have been demonstrated by means of the well-known quantum Brownian motion model of the recoilless limit (infinitely massive central system), as the principal interest lies in information transfer from the system to the environment. However, a final analysis relied on numerics. Here, after a presentation of the main concepts, we perform analytical studies of the model, showing the timescales and the efficiency of the spectrum broadcast structure formation. We consider a somewhat simplified environment, being random with a uniform distribution of frequencies.
Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction
- Oleksii Nosko
2016 TRIBOLOGY LETTERS
The instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction in the body. An analytical expression for the body motion is derived using the Laplace integral transform. It is shown that the sliding instability can manifest in the form of deviation of the body from the equilibrium position or in the form of oscillation. The instability conditions containing the friction–velocity and friction–temperature slope coefficients are obtained. Positive friction–temperature slope results in the deviation of the body from the equilibrium position. At negative friction–temperature slope, both types of the sliding instability can occur. The proposed instability conditions agree well with existing theoretical concepts and can be useful when designing tribosystems.
Analyzing the Geometry of the Turnouts and Their Adjustment Basing on the Tacheometer Measurements
- Strach Michał
- Karolina Makowska
2016
The article presents the results of tacheometric measurements of a station throat, as well as the method of data preparation and analysis. The calculations covered the verification of the geometry and the location of railway turnouts and crossings. The analyses were performed for the selected parameters of the turnout geometry, including their lengths and track gauge in main sections. In addition, the data were analyzed to confirm the location accuracy of individual turnouts in the station throat. In order to complete the geometrical characteristic, calculations were performed as to the location of the station throat components in relation to the geodetic railway network points. This element of the analyses enables to verify the spatial location of the analyzed structure.
Angle Tracking Observer for Filtering Rotor Position Estimates in Sensorless Electric Drives
- Leszek Jarzębowicz
- Maciej Cisek
- Artur Opaliński
2016 Full text Elektronika Ir Elektrotechnika
Sensorless electric drives use measurements of electrical quantities to estimate rotor position and speed. Measurement errors deteriorate the estimation accuracy, thus additional means are necessary to remove high-frequency components from estimated signals. This paper proposes to use an Angle Tracking Observer (ATO) for reducing noise in rotor position estimates, which is related to random errors in the measurements. A simplified, universal structure of ATO has been designed for this purpose. Based on simulations, the gains of ATO algorithm have been selected for optimal balance between error components related to the measurement noise and to the filtering lag. Additionally, implementation issues have been discussed and laboratory validation has been carried out in the paper. The designed ATO is applicable to any sensorless drive and enables drive controller to substantially improve rotor estimation accuracy using very low computing overhead.
Anioły biznesu jako niekonwencjonalne źródło finansowania przedsiębiorczości
- Gabriela Golawska-Witkowska
- Ewa Mazurek-Krasodomska
- Anna Rzeczycka
2016 Pieniądze i Więź
Podmioty gospodarcze, będąc elementem każdego modelu gospodarki, są bardzo istotne z punktu widzenia funkcjonowania wszystkich systemów ekonomicznych na świecie. Stan gospodarki jest bowiem silnie zależny od dynamicznego rozwoju sektora przedsiębiorczości. Zależność ta zachodzi na wszystkich etapach rozwoju gospodarczego, może ona jednak przybierać różne nasilenie i charakter. W Polsce, podobnie jak na całym świecie, powstaje wiele nowych przedsiębiorstw. Główną barierą ich rozwoju jest niewątpliwie brak kapitału. Wdro- żenie i realizacja obiecujących pomysłów są bardzo często niemożliwe z powodu braku funduszy. Dlatego też celem niniejszego artykułu jest ocena roli aniołów biznesu w finansowaniu przedsię- biorczości. Aniołowie biznesu pełnią bardzo ważną rolę na rynku kapitału ryzyka. Aktywnie oddziałują na zmniejszenie luki kapitałowej występującej w potrzebach przedsiębiorstw, a także zapewniają nowym, innowacyjnym firmom dostęp do kapitału, bez którego nie mogłyby one funkcjonować i rozwijać się. Stanowią więc kluczowy element rozwoju przedsiębiorstw we wczesnym stadium ich życia, stymulując rozwój sektora małych i średnich przedsiębiorstw. Dlatego należy tworzyć zachęty fiskalne dla potencjalnych inwestorów i zwiększyć poziom wiedzy z zakresu finansów i przedsiębiorczości. Przełoży się to na wzrost realizowanych przez anioły biznesu inwestycji i znaczny wzrost innowacyjności polskiej gospodarki.
Anion–water interactions of weakly hydrated anions: molecular dynamics simulations of aqueous NaBF4 and NaPF6
- Maciej Śmiechowski
2016 MOLECULAR PHYSICS
In aqueous ionic solutions, both the structure and the dynamics of water are altered dramatically with respect to the pure solvent. The emergence of novel experimental techniques makes these changes accessible to detailed investigations. At the same time, computational studies deliver unique possibilities for the interpretation of the experimental data at the molecular level. Here, using molecular dynamics simulations, we demonstrate how competing mechanisms can explain the seemingly contradictory statements about the structure and dynamics of ion-coordinated solvent in aqueous solutions of two interesting and technologically important electrolytes, NaBF4 and NaPF6. While the static structural data (i.e. radial, radial-angular and spatial distribution functions, as well as hydrogen bonding statistics) unequivocally point at very weak anion–water hydrogen bonding in both salts, dynamic analyses (in particular, orientational anisotropy decay and solvent residence times) reveal quite significant retardation of water rotation and mobility due to solute coordination. Additionally, rotational immobilisation of coordinated solvent molecules is clearly unrelated to the hydrogen bond strength between them, as demonstrated by the interatomic oxygen–oxygen distance distributions for coordinated and bulk water.
Annealing of indium tin oxide (ITO) coated optical fibers for optical and electrochemical sensing purposes
- Magdalena Dominik
- Katarzyna Siuzdak
- Paweł Niedziałkowski
- Vitezslav Stranak
- Petr Sezemsky
- Michał Sobaszek
- Robert Bogdanowicz
- Tadeusz Ossowski
- Mateusz Śmietana
2016
Glass and fiber structures with Indium Tin Oxide (ITO) coating were subjected to annealing in order to identify impact of the thermal treatment on their optical and electrochemical properties. It is shown that the annealing process significantly modifies optical properties and thickness of the films, which are crucial for performance of optical fiber sensors. Moreover, it visibly improves electrochemical activity of ITO on glass slides and thicker (∅=400 μm) ITO-coated fibers, whereas in the case of thinner fibers (∅=125 μm) it could lead to a loss of their electrochemical activity. Depending on the applied substrate and the annealing process, the investigated structures with ITO coating can be further used as fiber-based sensors with integrated opto-electrochemical readout.
Antimicrobal and ostheointegration activity of bone cement contains nanometals
- Beata Świeczko-Żurek
2016 Journal of Achievements in Materials and Manufacturing Engineering
Purpose: One of the major problems in bone surgery are infections – especially thoseoccurring in the course of the operating on the patients with lowered immunity system,because they carry the danger of complications. In the Mechanical Department of TechnicalUniversity of Gdansk, there has been carried the research with the use of bone cement andmetal nanoparticles.Design/methodology/approach: The bone cement was used without supplement orwith one or two drugs. These experiments are the latest, because include pure bone cement(without drugs) with nanometals. The titanium specimens was covering with such composecoating. The implant was inserted into rat`s thigh for six weeks. Afterwards the implantwas removed from the body and examined by means of scanning electron microscope.Simultanously biological research was carried out. Bonless samples were placed intobacterial liquid, generated by the researcher (the Patent number P 409082 ) containing fivemost frequently occurring bacteria in human body.Findings: Result of the SEM research was positive – there was good adhesion ofostheoblasts to the surface and there were no traces of infection.Practical implications: The research concerns bone cement with nanoparticles proves,that nanoparticles are the alternatives to antibiotics.
Antimicrobial molecular nanocarrier–drug conjugates
- Andrzej Stanisław Skwarecki
- Sławomir Milewski
- Marta Schielmann
- Maria Jolanta Milewska
2016 Nanomedicine-Nanotechnology Biology and Medicine
Many antimicrobial drugs are poorly active against pathogenic microbes causing intracellular infections, such as Mycobacterium tuberculosis or Plasmodium falciparum. On the other hand, several known antimicrobial agents are not effective enough because of their limited cellular penetration. A common feature of both challenges is the inability of an active agent to cross the biological membrane(s). One of the possible approaches facing these challenges is conjugation of an active substance with a molecular organic nanocarrier. The conjugate thus formed should be able to penetrate the membrane(s) and, once internalized, the active component could reach its intracellular target, either after release from the conjugate or in an intact form. Several molecular nanocarriers have been proposed: oligopeptides, including cell penetrating peptides, carbon nanotubes, siderophores, dendrimers, terpenoids and molecular umbrellas. A comprehensive review of the current status of molecular organic nanocarrier–drug conjugates and the future perspectives of their application as novel antimicrobials is presented.
Anti-theft lab security system based on RFID
- Bartosz Mudlaff
- Sylwia Babicz-Kiewlicz
- Janusz Smulko
2016 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
The aim of the project is to design and create an electronic system, which can be used to protect laboratory equipment against theft. The main task of the system is to warn a person responsible for the facilities about any attempts made to steal equipment from a laboratory. In a case of an alarm situation, the system emits a sound signal. The concept of the anti-theft security system based on RFID was developed on the basis of the analysis of the global market. Methods used to design each component of the system are described in detail, by presenting standards and electronic solutions applied in the developed hardware. Algorithms of the designed software embedded in each module and computer software are illustrated and explained. The method used to run and test the system is described.
Antitumor DNA-Damaging C-1748 is a New Inhibitor of Autophagy that Triggers Apoptosis in Human Pancreatic Cancer Cell Lines
- Barbara Borowa-Mazgaj
- Anna Skwarska
- Ewa Augustin
- Anna Radominska-Pandya
- Zofia Mazerska
2016 FASEB JOURNAL
Despite the enormous progress that has been made over the past decades in diagnosis, treatment and prevention of many types of tumors, survival rates in pancreatic cancer still remain poor. Pancreatic cancer is one of the most malignant and chemoresistant tumors and the profound mechanism supporting these phenomena is the constitutively activated prosurvival autophagy. The antitumor 1-nitroacridine derivative C-1748 belongs to a new set of DNA-damaging agents developed in our laboratory and is currently ready for phase I clinical trials. Here, we have uncovered a new role for C-1748 as a potent inhibitor of autophagy in four tested pancreatic cancer cell lines: Panc-1, MiaPaCa-2, BxPC-3 and AsPC-1. C-1748 treatment at 0.1 – 1 μM significantly reduced the typical hallmarks of autophagy, such as conversion of soluble LC3-I protein to its lipid-bound LC3-II isoform or development of acidic vesicular organelles, and importantly shifted pancreatic cancer cells into apoptotic cell death. Co-treatment with C-1748 and wortmannin, had a synergistic effect on autophagy inhibition and potentiated C-1748-induced apoptosis. In particular, compared with exposure to C-1748 alone, the combination treatment increased time- and dose-dependent cytotoxic activity of C-1748 with the most profound effect observed in BxPC-3 cells. Moreover, along with decrease in autophagy, co-treatment with wortmannin significantly elevated dysfunction of mitochondria, as manifested by a drop in mitochondrial membrane potential, increased caspase-3 activation, PARP cleavage, DNA fragmentation into apoptotic bodies and accumulation of lipid droplets arising due to the interruption of autophagy. In all studied cell lines, the level of apoptotic cells after dual exposure with C-1748 and wortmannin increased by about 20% as compared to C-1748 alone. Surprisingly, simultaneous exposure of pancreatic cancer cells to C-1748 in combination with the late-stage autophagy inhibitor, chloroquine, neither significantly increased the cytotoxic activity of C-1748 nor ameliorated its apoptosis-inducing potential. The synergistic effect of C-1748 and wortmannin on the inhibition of autophagy and lack of such effect when C-1748 was co-administered with chlroquine, suggests that C-1748, in addition to its DNA-damaging properties may also affects early stages of autophagy.
Antyoksydacyjne i przeciwdrobnoustrojowe właściwości bioaktywnych fitozwiązków żurawiny
- Monika Baranowska
- Agnieszka Bartoszek-Pączkowska
2016 Postępy Higieny i Medycyny Doświadczalnej
W racjonalnym żywieniu człowieka podkreśla się rolę owoców i warzyw, będących źródłem tzw. bioaktywnych fitozwiązków. Wśród owoców szczególną uwagę zwraca żurawina ze względu na wiele udokumentowanych właściwości prozdrowotnych. Owoc ten wyróżnia duża zawartość związków fenolowych o charakterze przeciwutleniaczy, które wspierają naturalny antyoksydacyjny system obronny organizmu przed uszkodzeniami wywołanymi stresem oksydacyjnym indukowanym przez reaktywne formy tlenu (RFT). Z tego względu żurawina jest zalecana w profilaktyce chorób cywilizacyjnych, takich jak miażdżyca, nadciśnienie, czy nowotwory, których etiologia jest bezpośrednio związana ze stresem oksydacyjnym. Jednak najlepiej udowodnionym działaniem zdrowotnym żurawiny są jej właściwości antybakteryjne wynikające z obecności charakterystycznych dla tego owocu proantocyjanidyn (PAC) typu A mających udokumentowane właściwości antyadherencyjne. Uznanym medycznym zastosowaniem owoców żurawiny jest profilaktyka oraz wspomaganie leczenia bakteryjnych zakażeń dróg moczowych (ZUM), błony śluzowej żołądka oraz infekcji jamy ustnej. Ze względu na powszechne stosowanie żurawiny oraz preparatów farmaceutycznych, których głównym składnikiem są PAC, w leczeniu ZUM bardzo ważna jest ocena wchłaniania, biodostępności oraz metabolizmu tych związków w organizmie człowieka.
APIS – Agent Platform for Integration of Services
- Michał Wójcik
- Paweł Napieracz
- Wojciech Jędruch
2016 Full text Annals of Computer Science and Information Systems
The paper presents an approach to creating the platform for development and evaluation of complex tasks execution algorithms. Proposed solution is based on an agent paradigm where independent peers can cooperate and negotiate in order to execute specified tasks which are defined only by the final output description. Tasks are realized by the means of services exposed by different peers. In case when there is no single service fulfilling the submitted task requirements there is a need for an automated composition of services into a complex workflow. The platform provides ready to use communication blocks which can be used for algorithms composition. All the algorithms developed on the platform are service implementation independent and are oriented on inter-agent communication.