2018 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2018

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Human subarachnoid space width oscillations in the resting state
- Marcin Gruszecki
- Gemma Lancaster
- Aneta Stefanovska
- Patric J. Neary
- Ryan Dech
- Wojciech Gumiński
- Andrzej F. Frydrychowski
- Jacek Kot
- Pawel Winklewski
2018 Full text Scientific Reports
Abnormal cerebrospinal fluid (CSF) pulsatility has been implicated in patients suffering from various diseases, including multiple sclerosis and hypertension. CSF pulsatility results in subarachnoid space (SAS) width changes, which can be measured with near-infrared transillumination backscattering sounding (NIR-T/BSS). The aim of this study was to combine NIR-T/BSS and wavelet analysis methods to characterise the dynamics of the SAS width within a wide range of frequencies from 0.005 to 2 Hz, with low frequencies studied in detail for the first time. From recordings in the resting state, we also demonstrate the relationships between SAS width in both hemispheres of the brain, and investigate how the SAS width dynamics is related to the blood pressure (BP). These investigations also revealed influences of age and SAS correlation on the dynamics of SAS width and its similarity with the BP. Combination of NIR-T/BSS and time-frequency analysis may open up new frontiers in the understanding and diagnosis of various neurodegenerative and ageing related diseases to improve diagnostic procedures and patient prognosis.
Hyaluronan-Chondroitin Sulfate Anomalous Crosslinking Due to Temperature Changes
- Tomasz Andrysiak
- Piotr Bełdowski
- Jacek Siódmiak
- Piotr Weber
- Damian Ledziński
2018 Full text Polymers
Glycosaminoglycans are a wide class of biopolymers showing great lubricating properties due to their structure and high afﬁnity to water. Two of them, hyaluronic acid and chondroitin sulfate, play an important role in articular cartilage lubrication. In this work, we present results of the all-atom molecular dynamics simulations of both molecules placed in water-based solution. To mimic changes of the physiological conditions, especially temperature, of the synovial ﬂuid in joints under successive load (e.g., walking, jogging, jumping), simulations have been performed at different physiological temperatures in the range of 300 to 320 Kelvin (normal intra-articular temperature is305K).The stability of the biopolymeric network at equilibrium(isothermal and isobaric) conditions has been studied. To understand the process of physical crosslinking, the dynamics of intra- and intermolecular hydrogen bonds forming and breaking have been studied. The results show that following addition of chondroitin sulfate, hyaluronan creates more intermolecular hydrogen bonds than when in homogeneous solution. The presence of chondroitin in a hyaluronan network is beneﬁcialas it may increase its stability. Presented data show hyaluronic acid and chondroitin sulfate as viscosity modiﬁers related to their crosslinking properties in different physicochemical conditions.
Hybrid Processing by Turning and Burnishing of Machine Components
- Włodzimierz Przybylski
- Stefan Dzionk
2018
The paper presents a method of hybrid manufacturing process of long 5 shafts and deep holes by simultaneous turning and burnishing method. The tech- 6 nological results of the research focus on the influence of the basic technological 7 parameters of this process on the surface roughness of piston rods of hydraulic 8 cylinders. Research results are presented in the graphs as well as mathematical 9 formula. Set of samples were made of steel (C45) as a rod with slenderness ratio (l/ 10 d) 5–20 and a diameter 56 mm. It shows as well the original CNC machine, which 11 can perform hybrid process (turning and burnishing) of rods and shafts which 12 diameters are in the range 20–100 mm and maximum length 1750 mm.
Hybrid stepless distribution transformer with four-quadrant AC/DC/AC converter at low voltage side - simulation tests
- Ryszard Strzelecki
- Wojciech Matelski
- Valentin Tomasov
2018 Full text Przegląd Elektrotechniczny
The article presents the work of the stepless hybrid distribution transformer (HT), as an alternative to the so far applied Automatic Voltage Regulator (AVR) solutions, used to control the voltage in the power system in terms of the fundamental harmonic. The HT is a combination of a conventional distribution transformer and an AC/DC/AC converter connected in series with the transformers secondary winding. In the work the basic control algorithm of the AC/DC/AC converter operated as a series connected additive voltage source in the HT system, has been described. The article contains the preliminary results of computer simulation studies of the model elaborated in PSIM.
Hybrid storage management system consisting of supercapacitors and AHI batteries
- Leszek Wolski
- Eugeniusz Łowiec
- Piotr Bogusławski
- Antoni Krahel
- Wojciech Matelski
- Ryszard Strzelecki
2018
In the article the hybrid storage, composed of Aqueous Hybrid Ion battery and supercapacitor was presented. The system was tested through simulation studies. The work also describes the construction and properties of the developed device meant to control the energy flow of the storage and a communication system for remote parameter supervision.
Hybrydowe modele i metody modelowania układów mechanicznych
- Rafał Hein
2018
W monografii przedstawiono metody modelowania układów mechanicznych umożliwiające uzyskanie odpowiednio dokładnych modeli niskiego rzędu. Jedną z nich jest dyskretno-ciągła metoda pryzm (DCMP). Łączy ona zalety metod modelowania układów ciągłych o parametrach rozłożonych i dyskretyzowanych przestrzennie o parametrach skupionych. Jej opis matematyczny wyprowadzono posługując się metodami sztywnych elementów skończonych i transmitancji układów o parametrach rozłożonych. Prowadzi ona do modeli dyskretno-ciągłych, które są dokładniejsze od modeli MES przy porównywalnej liczbie elementów lub zbliżonych rzędach tych modeli. W pracy przedstawiono także metody hybrydowego modelowania modalnego układów jednowymiarowych o parametrach rozłożonych, wielowymiarowych o parametrach skupionych i wielowymiarowych opisywanych dyskretno-ciągłą metodą pryzm. Polegają one na wiązaniu dwóch modeli składowych, z których jeden jest zredukowanym modelem modalnym tej części układu, dla której łatwo jest formułować warunki ortogonalności, zaś drugi modelem dyskretnym pozostałej jego części. Do wyznaczania wartości i funkcji własnych oraz mas i sztywności modalnych zredukowanego modelu modalnego wykorzystuje się metodę transmitancji układów o parametrach rozłożonych. Dzięki temu uwzględnione częstości własne modeli modalnych są dokładne a modele hybrydowe dokładniejsze. Uzyskiwane w ten sposób modele mogą uwzględniać efekty żyroskopowe, Coriolisa, a także zjawiska prowadzące do nieliniowych modeli matematycznych. Przedstawione metody mogą znaleźć zastosowanie m.in. do modelowania obiektów regulacji w układach sterowania, w których szczególnie pożądane są modele niskiego rzędu.
Hydraulic potential of the Lower Vistula (Poland)
- Michał Szydłowski
- Romuald Szymkiewicz
- Dariusz Gąsiorowski
- Jakub Hakiel
- Piotr Zima
2018
The Vistula is the largest river in Poland. Lower Vistula (part of the river discussed in this paper) is almost four hundred kilometers long river section extending from the tributary Narew to the outflow to the Baltic Sea. In the 17th century the Vistula was the most navigable river in Europe. After partitioning of Poland the Vistula lost its significance. Now the Lower Vistula should provide a navigation connection to the Europe forming water routes E70 and E40. However it does not meet the criteria required for the international waterways. Moreover, the river has a quite large hydro-energy potential. There have been many plans for the development of the Lower Vistula River so far. Unfortunately none of them has been implemented. In this paper, the authors would like to present their own arguments to reactivate the Lower Vistula Cascade (LVC) project. In order to analyse the LVC idea and Lower Vistula hydraulic potential, a numerical hydraulic model of the Lower Vistula was developed at the Department of Hydraulic Engineering of Gdansk University of Technology. Various aspects of the LVC concept, such a potential inland waterways, hydropower, flood control and water retention, are discussed in the article.
Hydro Lubricants: Water-based lubricants for hydropower applications
- Wojciech Litwin
- Vengudusamy Balasubramaniam
- Elena von Hoersten
- Schweigkofler Martin
- Kuhn Marius
2018
Several different base oil types exist in the market including mineral and synthetic oils (e.g. polyalphaolefins, ester, polyglycol, etc.) and are currently widely in use. Although synthetic oils have drawn great attention over the past few decades in terms of their tribological benefits, mineral oils are still widely used in hydropower applications due primarily to their low cost and easy miscibility with other oils. However, despite their widespread use, the industrial world is moving towards more environmentally friendly and sustainable solutions as conventional lubricants pose a serious concern to aquatic life caused potentially by the leakage of them into downstream water. In addition to this, they also have reached their functional limits concerning tribological properties.
Hydrodron — New Step for Professional Hydrography for Restricted Waters
- Andrzej Stateczny
- Daria Gronska
- Weronika Motyl
2018
Hydrographic surveys in restricted areas are becoming increasingly important, but often impossible to carry out with conventional hydrographic vessels. Presumably in this case an employment of unmanned vehicles is the only reasonable solution. As restricted water areas include, among others: harbours, roadsteads, rivers or lakes. The HydroDron platform, due to its mobility, can operate in the above-mentioned areas. It is adapted to perform hydrographic survey missions in the field of bathymetric measurements, sonar measurements and others in two modes: remote control or autonomous. Furthemore, HydroDron is multi-variant, which allows any configuration of measurement systems to relieve the ship, along with the reduction of research costs. Selected measurement systems were analyzed: PingDSP 3DSS-DX-450, EdgeTech 6205, Klein HydroChart3500 [1, 2] and integrated inertial systems: SBG Ekinox 2-D, Applanix POS MV WaveMaster. The equipment which is part of the HydroDron platform is configured to minimize the human contribution while surveying on restricted water areas.
Hydrogen production from biomass using dark fermentation
- Rafał Łukajtis
- Iwona Hołowacz
- Karolina Kucharska
- Marta Glinka
- Piotr Rybarczyk
- Andrzej Przyjazny
- Marian Antoni Kamiński
2018 Full text RENEWABLE & SUSTAINABLE ENERGY REVIEWS
Hydrogen applicability in the power, chemical and petrochemical industries is constantly growing. Eﬃcientmethods of hydrogen generation from renewable sources, including waste products, are currently being de-veloped, even though hydrogen is mainly produced through steam reforming or thermal cracking of natural gasor petroleum fractions. In paper alternative methods of hydrogen production with a particular emphasis on darkfermentation are discussed. The review compiles essential information on strains of bacteria used in the pro-duction of hydrogen from waste products in the agroindustry and from lignocellulosic biomass. The eﬀect ofsuch parameters as kind of raw material, method of processing, temperature, pH, substrate concentration, partialpressure of hydrogen, hydraulic retention time, method of inoculum preparation and the type and operatingparameters of a reactor on the yield of dark fermentation is discussed. The review aims at presentation of currentstate of knowledge on the dark fermentation process utilizing waste materials as substrates. The results of in-vestigations with emphasis on the most important issues regarding operating parameters of dark fermentationare also included.
Hydrogen Production from Energy Poplar Preceded by MEA Pre-Treatment and Enzymatic Hydrolysis
- Karolina Kucharska
- Rafał Łukajtis
- Edyta Słupek
- Hubert Cieśliński
- Piotr Rybarczyk
- Marian Antoni Kamiński
2018 Full text MOLECULES
The need to pre-treat lignocellulosic biomass prior to dark fermentation results primarily from the composition of lignocellulose because lignin hinders the processing of hard wood towards useful products. Hence, in this work a two-step approach for the pre-treatment of energy poplar, including alkaline pre-treatment and enzymatic saccharification followed by fermentation has been studied. Monoethanolamine (MEA) was used as the alkaline catalyst and diatomite immobilized bed enzymes were used during saccharification. The response surface methodology (RSM) method was used to determine the optimal alkaline pre-treatment conditions resulting in the highest values of both total released sugars (TRS) yield and degree of lignin removal. Three variable parameters (temperature, MEA concentration, time) were selected to optimize the alkaline pre-treatment conditions. The research was carried out using the Box-Behnken design. Additionally, the possibility of the re-use of both alkaline as well as enzymatic reagents was investigated. Obtained hydrolysates were subjected to dark fermentation in batch reactors performed by Enterobacter aerogenes ATCC 13048 with a final result of 22.99 mL H2/g energy poplar (0.6 mol H2/mol TRS).
HYDROGEN PRODUCTION PERFORMANCE IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF NI3AL
- Janusz Badur
- Michał Stajnke
- Paweł Ziółkowski
- Paweł Jóźwik
- Zbigniew Bojar
- Piotr Ziółkowski
2018
The main aim of the following paper is mathematical modelling for momentum, heat and mass transfer, which is accompanied by chemical surface reactions of the flow of the mixture helium and methanol. The thermocatalytic devices used for decomposition of hydrocarbons incorporate vertical microchannels coupling at the ends and heated to 500 oC at the walls. The results of the experiment were compared with CFD calculations to calibrate the constants of the model UDFs (User Defined Functions). These extensions transformed the calculations mechanisms and algorithms of commercial codes adapting them for the micro-flows cases and increased chemical reactions rate on an interphase between fluid and solid. Results obtained on the way of numerical calculations have been calibrated and compared with the experimental data to receive satisfactory compliance. The model has been verified and the performance of the thermocatalytic reactor with microchannels under hydrogen production regime has been investigated.
Hydrographic Multisensory Unmanned Watercraft
- Krzysztof Pyrchla
- Jerzy Pyrchla
- Tadeusz Kantak
2018 KSCE Journal of Civil Engineering
This article describes the design of the unmanned surface vessel (USV) and the algorithms for planning the trajectories to be followed on measurement missions. The algorithms take account of the dynamically varying impacts of external forces (wind and surface current) on the vessel's motion. Feedback loops enable the counteraction of external factors that cause disturbance to the desired trajectory. The sensors installed on the vessel provide information about the surroundings and adjust the parameters of its motion to provide optimum completion of the planned trajectory and to prevent collisions with fixed and moving obstacles. The nature of the hydrographic work planned to be carried out by the craft requires that it be designed with the following features: shallow draft, high stability, the absence of interference of the measurement sensors by the engine, and high energy efficiency. These features will give a competitive advantage over similar platforms available on the market.
Hydroperoxyl radical and formic acid formation from common DNA stabilizers upon low energy electron attachment
- Anita Ribar
- Stefan Huber
- Małgorzata Śmiałek-Telega
- Katrin Tanzer
- Michael Neustetter
- Robin Schürmann
- Ilko Bald
- Stephan Denifl
2018 PHYSICAL CHEMISTRY CHEMICAL PHYSICS
2-Amino-2-(hydroxymethyl)-1,3-propanediol (TRIS) and ethylenediaminetetraacetic acid (EDTA) are key components of biological buffers and are frequently used as DNA stabilizers in irradiation studies. Such surface or liquid phase studies are done with the aim to understand the fundamental mechanisms of DNA radiation damage and to improve cancer radiotherapy. When ionizing radiation is used, abundant secondary electrons are formed during the irradiation process, which are able to attach to the molecular compounds present on the surface. In the present study we experimentally investigate low energy electron attachment to TRIS and methyliminodiacetic acid (MIDA), an analogue of EDTA, supported by quantum chemical calculations. The most prominent dissociation channel for TRIS is through hydroperoxyl radical formation, whereas the dissociation of MIDA results in the formation of formic and acetic acid. These compounds are well-known to cause DNA modifications, like strand breaks. The present results indicate that buffer compounds may not have an exclusive protecting effect on DNA as suggested previously.
Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
- Patrycja Makoś
- Andrzej Przyjazny
- Grzegorz Boczkaj
2018 Full text JOURNAL OF CHROMATOGRAPHY A
The paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons from aqueous samples characterized by a complex matrix. The final determination was carried out by gas chromatography-mass spectrometry. The most important extraction parameters were optimized and the procedure was validated. The developed procedure is characterized by low limits of detection and quantitation, equal to 0.0039–0.0098 μg/L and 0.012–0.029 μg/L, respectively, good precision (RSD <6.09%), analyte recovery ranging from 73.5 to 126.2%, and a wide linear range. The procedure was applied to analysis of industrial effluents from the production of bitumens before and after treatment by advanced oxidation processes. A total of 16 PAHs at concentrations ranging from 0.12 to 46.2 μg/L were identified and determined.
HYDROSTATIC THRUST BEARING WITH REDUCED POWER LOSSES
- Filip Wasilczuk
- Michał Wasilczuk
- Michał Wodtke
2018 Full text TRIBOLOGIA
In many cases in rotating machinery, axial load is carried by tilting pad thrust bearings which have been developed since the beginning of 20th century. For high reliability and simplicity, most commonly the bearings are bath lubricated. In the times of sustainable development, however, minimization of friction losses becomes an important criterion for machinery assessment, and a strategic goal of their development. Performed calculations, based on elementary rules of fluid dynamics, showed that shearing losses in specially designed hydrostatic bearings can be considerably smaller than the losses in tilting pad hydrodynamic bearings. The aim of the research described in this paper was to check if the preliminary results presented earlier and conclusions of benefits of the further increase of the size of the hydrostatic pocket can be confirmed with the use of CFD calculations.
Identification of Continuous Systems - Practical Issues of Insensitivity to Perturbations
- Janusz Kozłowski
- Zdzisław Kowalczuk
2018 Full text Advances in Intelligent Systems and Computing
In this paper the issue of continuous systems estimation, insensitive to certain perturbations, is discussed. Such an approach has rational advantages, especially when robust schemes are used to assist a target system responsible for industrial diagnostics. This requires that estimated model parameters are generated on-line, and their values are reliable and to a great extent accurate. Practical hints are suggested to challenge the consistency problem of estimates. In particular, the technique of instrumental variables can improve the asymptotic behavior of estimators. With a weighting mechanism, in turn, tracking the time-varying parameters of non-stationary processes is realistic. Yet, evident insensitivity to destructive outliers in the measurement data follows from the implemented estimation routine in the sense of the least sum of absolute errors. Finally, premises for a proper selection of excitation signals, as well as the directions of further research summarize the paper.
Identification of Emotions Based on Human Facial Expressions Using a Color-Space Approach
- Zdzisław Kowalczuk
- Piotr Chudziak
2018 Full text
HCI technology improves human-computer interaction. Such communication can be carried out with the use of emotions that are visible on the human face since birth. In this paper the Emotion system for detecting and recognizing facial expressions, developed in the MSc work, is presented. The system recognizes emotion from webcam video in real time. It is based on color segmentation and morphological operations. The system uses a cascade of boosted classifiers based on Haar-like features, to locate the face and to reduce the searched area for characteristic points. For identification purposes, the Emotion system uses an expanded action unit EAU, based on a facial action coding system FACS.
Identification of nonstationary multivariate autoregressive processes– Comparison of competitive and collaborative strategies for joint selection of estimation bandwidth and model order
- Maciej Niedźwiecki
- Marcin Ciołek
2018 Full text DIGITAL SIGNAL PROCESSING
The problem of identification of multivariate autoregressive processes (systems or signals) with unknown and possibly time-varying model order and time-varying rate of parameter variation is considered and solved using parallel estimation approach. Under this approach, several local estimation algorithms, with different order and bandwidth settings, are run simultaneously and compared based on their predictive performance. First, the competitive decision schemes are considered. It is shown that the best parameter tracking results can be obtained when the order is selected based on minimization of the appropriately modified Akaike’s final prediction error statistic, and the bandwidth is chosen using the localized version of the Rissanen’s predictive least squares statistic. Next, it is shown that estimation results can be further improved if a collaborative decision is made by means of applying the Bayesian model averaging technique.
Identification of nonstationary processes using noncausal bidirectional lattice filtering
- Maciej Niedźwiecki
- Damian Chojnacki
2018 Full text
The problem of off-line identification of a nonstationary autoregressive process with a time-varying order and a time-varying degree of nonstationarity is considered and solved using the parallel estimation approach. The proposed parallel estimation scheme is made up of several bidirectional (noncausal) exponentially weighted lattice algorithms with different estimation memory and order settings. It is shown that optimization of both settings can be carried out by means of minimization of the locally