2019 - Repozytorium publikacji - Politechnika Gdańska

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A new dilution-enrichment sample preparation strategy for expanded metabolome monitoring of human breast milk that overcomes the simultaneous presence of low- and high-abundance lipid species
- Weronika Hewelt-Belka
- Dorota Garwolińska
- Mariusz Belka
- Tomasz Bączek
- Jacek Namieśnik
- Agata Kot-Wasik
2019 FOOD CHEMISTRY
The complex nature of human breast milk (HBM) makes samples difficult to analyze, requiring several extraction techniques and analytical platforms to obtain high metabolome coverage. In this work, we combined liquid-liquid extraction (LLE) and solid-phase extraction (SPE) techniques to prepare HBM samples to overcome the challenge of low- and high-abundance lipid species, enabling the semiquantitative analysis of total HBM lipids in one liquid chromatography-mass spectrometry (LC-MS) run. A nonorganic fraction obtained during the LLE step was used to analyze small polar metabolites. This analytical approach allows extensive metabolome coverage, especially for low-abundance glycerophospholipids and sphingolipids. The method was applied to monitor short-term metabolome changes in HBM composition within individual mothers and the results showed variable metabolite composition patterns. Simultaneous detection of high-abundance glycerolipids and low-abundance but not less significant phospholipids in one LC-MS run saves time, decreases cost, and enables comprehensive insight into the dynamics of HBM composition.
A New Geodetic Method of Examination of Geometrical Conditions of a Crane Bridge
- Daria Filipiak-Kowszyk
- Waldemar Kamiński
- Karolina Makowska
2019 Pełny tekst Geosciences
Safety is one of the key aspects related to crane-based material transport. In order to ensure safe crane operation and material transport, it is necessary to meet certain geometrical conditions. The authors addressed the geometrical conditions of a crane bridge, a substantial crane component. The paper presents the method to compute displacement components of points on the top of a bridge crane relative to their design position. Theoretical considerations presented in the paper have been verified on simulated data. Keeping in mind the proper operation of a crane bridge, the authors proposed in the analyses the use of geometrical relations (perpendicular and parallel character) between end carriages and girders, not previously included in the available literature. The obtained results show that the presented method may be successfully applied to check the geometry of a crane bridge.
A NEW MASTER'S DEGREE PROGRAM IN GEODESY
- Paweł Wysocki
- Dominika Wróblewska
2019
Faculty of Civil and Environmental Engineering (WILiS) at Gdansk University of Technology (GUT) offers studies in the fields of Geodesy and Cartography. The bachelor program (7 semesters) was started ten years ago in 2009. It provides the student with the basic skills and knowledge in the fields of surveying, geodesy and more generally geomatics and cartography. It is strongly related to expertise knowledge of civil building (geodetic monitoring systems) and environmental engineering (photogrammetry and laser detection). During 2014 - 2017 years students were able to continue studying at postgraduate course and get MSc degree at Surveying Techniques in Engineering, an inter-faculty course. The observation of the labour market requirements indicated the need for graduates prepared to solve specific knowledge enabling solving engineering problems and with wide set of soft skills. As a response, a new master degree program in the field of geodesy and cartography was prepared and started in 2017 in specialization of geomatics and geoinformatics. This studies prepare the graduate for employment in surveying and research companies with interdisciplinary knowledge and a special focus on geomatics and geoinformatics or photogrammetry and remote sensing. The curriculum is also prepared to enable graduates to gain professional qualifications in the field of photogrammetry and remote sensing. The article presents objectives, structure and contents of a new master degree level studies and its relation to the labour qualifications and research conducted by academic teachers employed in Department of Geodesy
A new method and equipment for the detection of presence and estimation of the content of the petroleum-based fraction in lubricating oils, especially those emitted to the atmosphere
- Paulina Nowak
- Marian Antoni Kamiński
- Piotr Rybarczyk
- Karolina Kucharska
2019 Aparatura Badawcza i Dydaktyczna
Lubricating oil, used in cutting equipment, works in the so-called open lubrication system and is entirely emitted to the environment. When such an oil contains even a small portion of the crude oil-derived fraction, which is still very common, the oil is a serious environmental pollution. In addition, the oil mist poses a serious threat to the health of employees. Current legal regulations require users of saws and harvesters to use only biodegradable oils. In the case of hydraulic oils used in machines and vehicles, there is always a risk of leakage into the environment e.g. in case of breakage of connecting pipes or other types of breakdowns. Therefore, it seems reasonable to postulate the use of biodegradable oils in power hydraulics systems of machines used in forests, fields, mines or in rail or road vehicles. Bio-degradable oil, most often, with base vegetable oil, is more expensive than lubricating oil produced with the use of an oil-based oil base – i.e. a product of oil refining. Today, users of saws and harvesters still use mineral lubricating oils from crude oil, without any attention to the negative consequences for health and the environment. The known methods of the assessment of biodegradability of lubricating oils are expensive and time-consuming. The paper proposes a principle of method and equipment for performing a quick and cheap screening test for the presence of petroleum-derived fractions containing aromatic hydrocarbons in the analyzed lubricating oil samples. The test uses an oil fluorescence test under UV light of wavelength λ = 365 nm. The proposed method is simple and does not require specialist qualifications from the user. Easy-to-prepare equipment for repetitive testing in field conditions has been described.
A New Rehabilitation Device for Balance Impaired Individuals
- Wiktor Sieklicki
- Robert Barański
- Szymon Grocholski
- Patrycja Matejek
- Mateusz Dyrda
- Konrad Klepacki
2019
In the paper authors present a device designed to improve the rehabilitation process of people with balance impairment. The discussed device (JStep) utilizes a commercially available static standing frame (stander) modified in order to fit force sensing units under the feet and in the pillows around the hips of a patient. While executing rehabilitation tasks, the patient may compensate his balance deficiency by leaning on the pillows around his hips. Information about weight distribution between left and right leg together with the information about the force applied to the pillows supporting the patient's body is further presented on a display in front of the patient. Such a setup allows physicians to work with the patient while having direct information about compensation necessary for completing a task or gives the patient a visual biofeedback about how well he is doing the exercise. The system is based on an ATmega controller, load cells and analogue amplifiers. In this framework a case study is presented of a 16 y.o. patient with Cerebral Palsy affecting his cerebellum, labelled as ataxic Cerebral Palsy. Two exercise scenarios utilizing the proposed device are discussed and results of a 6-week exercise are further presented. They show a decrease in necessary compensation in order to maintain a standing posture as well as a better accuracy in achieving the desired force distribution between right and left leg while standing upright.
A new simple approach to prepare rare-earth metals-modified TiO2 nanotube arrays photoactive under visible light: Surface properties and mechanism investigation
- Patrycja Parnicka
- P. Mazierski
- Wojciech Lisowski
- Tomasz Klimczuk
- Joanna Nadolna
- Adriana Zaleska-Medynska
2019 Pełny tekst Results in Physics
Application of Ti90RE10 alloys (RE = Ho, Er, Nd, Y, Ce, Tm) as a working electrode, instead of Ti pure foil in anodic oxidation in a fluoride-based electrolyte, resulted in formation of well-ordered nanotubes made of TiO2 and RE2O3 mixture, which could be efficiently used for pollutant removal from water and air phase upon UV and visible irradiation and easily separable from the reaction mixture to recycle. The as-prepared NTs were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), diffuse reflectance spectroscopy (DRS), luminescence spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the synthesized samples was investigated used phenol and toluene as a model compounds to follow degradation kinetics. The influence of the RE metals on the photoelectrochemical performance of modified TiO2 NTs was investigated. Surface morphology analysis showed formation of uniform and vertically oriented NTs structures with an open tube top and smooth walls. The results of EDX, XRD and XPS analysis proved that RE ions exist as surface compounds (RE3+ oxides). Visible light induced photoactivity (both photocatalytic and photoelectrochemical) is mostly pronounced in the presence of nanotubes obtained by anodic oxidation of Ti90Ho10 alloy. These nanotubes are able to degrade toluene in the gas phase even by irradiation of low-powered light source, such as light emitting diodes (λmax = 465 nm). Photocatalytic test of phenol degradation in the presence of scavenger indicates that photogenerated electrons and superoxide radicals play a meaningful role in the photocatalytic degradation of pollutants under visible irradiation. In addition, the photoelectrochemical tests performed under the influence of visible light irradiation confirmed that the RE-modification of TiO2 NTs caused a significant increase of photocurrent (up to 10 times higher). The new and original results on the preparation of RE2O3/TiO2 nanotubes obtained in one step anodic oxidation and photocatalytic activity in aqueous and gas phases represent an important contribution then will benefit photocatalytic surfaces preparation technologies.
A NEW TAKE ON PENITENTIARY ARCHITECTURE ARCHITEKTURA WIĘZIENNA – NOWE OBLICZE
- Agnieszka Szuta
2019 Pełny tekst Przestrzeń i Forma
This article raises the issue of designing and adapting correctional facilities to the new perception of prisoners as well as comprehension of punishment. For research purposes, several European prisons which came into service over recent years were selected. A study of such facilities revealed design solutions that may significantly affect the process of rehabilitation for inmates and make such buildings an accepted part of society.
A Novel Approach of Using Selected Unconventional Geodesic Methods of Estimation on VTS Areas
- Krzysztof Czaplewski
- Mariusz Wąż
- Marek Zienkiewicz
2019 MARINE GEODESY
The Vessel Traffic Service (VTS) systems belong to the fundamental tools used in ensuring a high level of safety across sea basins with heavy traffic, where the presence of navigational hazards poses a great risk of collision or a ship running aground. In order to determine the mutual location of ships, VTS systems obtain information from different facilities, such as coastal radar stations, AIS, and vision systems. Fixing a ship’s position is always accompanied by a degree of error, but the degree of error depends on the specific position fixing system used. In order to increase the accuracy of position fixing in VTS systems, the authors propose the use of contemporary geodetic methods. The article presents the theoretical fundamentals of two unconventional geodesic methods of estimation: M estimation and Msplit(q)estimation and the authors’ own proposal of their application in VTS systems. The article concludes with a test verifying theoretical assumptions, performed with the use of a computer application allowing position fixing with the use of selected robust adjustment methods. Furthermore, an example is presented of Msplit(q)estimation as used for the acquisition of low-signal radar echoes, which in VTS systems are not automatically identified for tracking. The level of the echo signal makes it difficult for a VTS controller to separate these objects from typical radar noise and interference.
A Novel Bitrate Adaptation Method for Heterogeneous Wireless Body Area Networks
- Krzysztof Cwalina
- Sławomir Ambroziak
- Piotr Rajchowski
- Jarosław Sadowski
- Jacek Stefański
2019
In the article, a novel bitrate adaptation method for data streams allocation in heterogeneous Wireless Body Area Networks (WBANs) is presented. The efficiency of the proposed algorithm was compared with other known algorithms of data stream allocation using computer simulation. A dedicated simulator has been developed using results of measurements in the real environment. The usage of the proposed adaptive data streams allocation method by transmission rate adaptation based on radio channel parameters can increase the efficiency of resources’ usage in a heterogeneous WBANs, in relation to fixed bitrates transmissions and the use of well-known algorithms. This increase of efficiency has been shown regardless of the mobile node placement on the human body.
A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
- Jacek Lachowicz
- Magdalena Rucka
2019 Pełny tekst CONSTRUCTION AND BUILDING MATERIALS
The ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants of concrete is developed, based on the modified complex refractive index method. Experimental surveys and numerical simulations are conducted on a concrete laboratory sample with a controlled degree of saturation, and on a real concrete slab with two different degrees of saturation. The results indicate that the proposed model is fully capable of realistic finite-difference time-domain modelling of concrete for ground penetrating radar diagnostics of civil engineering structures with changing water content.
A Novel IoT-Perceptive Human Activity Recognition (HAR) Approach Using Multi-Head Convolutional Attention
- Haoxi Zhang
- Zhiwen Xiao
- Juan Wang
- Fei Li
- Edward Szczerbicki
2019 Pełny tekst IEEE Internet of Things Journal
Together with fast advancement of the Internet of Things (IoT), smart healthcare applications and systems are equipped with increasingly more wearable sensors and mobile devices. These sensors are used not only to collect data, but also, and more importantly, to assist in daily activity tracking and analyzing of their users. Various human activity recognition (HAR) approaches are used to enhance such tracking. Most of the existing HAR methods depend on exploratory case-based shallow feature learning architectures, which straggle with correct activity recognition when put into real life practice. To tackle this problem, we propose a novel approach that utilizes the convolutional neural networks (CNNs) and the attention mechanism for HAR. In the presented method, the activity recognition accuracy is improved by incorporating attention into multi-head convolutional neural networks for better feature extraction and selection. Proof of concept experiments are conducted on a publicly available dataset from Wireless Sensor Data Mining (WISDM) laboratory. The results demonstrate higher accuracy of our proposed approach in comparison with the current methods.
A Novel Trust-Region-Based Algorithm with Flexible Jacobian Updates for Expedited Optimization of High-Frequency Structures
- Anna Pietrenko-Dąbrowska
2019 Pełny tekst INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
Simulation-driven design closure is mandatory in the design of contemporary high-frequency components. It aims at improving the selected performance figures through adjustment of the structure’s geometry (and/or material) parameters. The computational cost of this process when employing numerical optimization is often prohibitively high, which is a strong motivation for the development of more efficient methods. This is especially important in the case of complex and multi-parameter structures. In the paper, an expedited trust-region-based algorithm for electromagnetic (EM)-driven design optimization of high-frequency structures is proposed. The presented technique involves a flexible sensitivity update scheme depending on the relative design changes with respect to the trust region size, as well as a direction of the design relocation and its alignment with the coordinate system axes. This allows for performing finite-differentiation-based sensitivity updates less frequently and, consequently, brings considerable computational savings. Numerical results obtained for an ultra-wideband antenna and a microwave coupler demonstrate that the proposed algorithm outperforms the reference procedure in terms of the number of EM simulations necessary to arrive at the optimized solution (around 50 percent). At the same time, the design quality loss is minor.
A numerical analysis of the thermal effects in the jet impingement stagnation zone
- Tomasz Kura
- Elżbieta Fornalik-Wajs
- Jan Wajs
- Sasa Kenjeres
- Sebastian Gurgul
2019
Most of the flows occurring in the engineering systems are turbulent and their accurate numerical analysis is still challenging, especially when combined with the heat transfer. One of the methods of heat transfer enhancement is utilization of the turbulent impinging jets, which were recently applied also in the heat exchangers. Their positive impact on the heat transfer performance was proven, but many questions related to its origin are still unanswered. In general, the wall-jet interaction and the near-wall turbulence are supposed to be its main reason. The authors are interested in construction of the numerical model assuring the results as close as possible to the experimental one and then modelling the transport processes in the heat exchanger. The most difficult area to model is the stagnation region, where the thermal effects are strongly affected by the conditions in the pipe/nozzle/orifice, from which the jet is originated. In the following article, summary of authors’ findings, regarding significance of the velocity profile or turbulence intensity at the inlet, are presented. In addition, qualitative analysis of the heat transfer enhancement is included, in relation to the inlet conditions.
A Reduction Method for Bathymetric Datasets that Preserves True Coastal Water Geodata
- Marta Wlodarczyk-Sielicka
- Andrzej Stateczny
- Jacek Lubczonek
2019 Pełny tekst Remote Sensing
Water areas occupy over 70 percent of the Earth’s surface and are constantly subject to research and analysis. Often, hydrographic remote sensors are used for such research, which allow for the collection of information on the shape of the water area bottom and the objects located on it. Information about the quality and reliability of the depth data is important, especially during coastal modelling. In-shore areas are liable to continuous transformations and they must be monitored and analyzed. Presently, bathymetric geodata are usually collected via modern hydrographic systems and comprise very large data point sequences that must then be connected using long and laborious processing sequences including reduction. As existing bathymetric data reduction methods utilize interpolated values, there is a clear requirement to search for new solutions. Considering the accuracy of bathymetric maps, a new method is presented here that allows real geodata to be maintained, specifically position and depth. This study presents a description of a developed method for reducing geodata while maintaining true survey values.
A SEARCH OF AN INDUCER GEOMETRY THAT IS BENEFICIAL FOR LIFTING PARAMETERS OF A LIFTED OBJECT OF A SELECTED SHAPE
- Bartosz Bastian
- Rafał Gawarkiewicz
2019 Pełny tekst TRIBOLOGIA
The literature describes acoustic levitation phenomena with the utilization of air squeeze film between the vibrating inducer and the lifted object. The objective of the study is to determine the shape of the inducer with vibration characteristics that would allow the levitation of an object of the assumed geometry. In this paper, the influence of the dimension ratio of the inducer on the frequency of the first mode of vibration was presented. CFD calculations for a selected dimension series were performed with the goal of the determination of lifting conditions. The data obtained from the analysis will be used to manufacture an inducer that will serve as an experimental verification for the fluid dynamics calculation.
A semi-empirical model for flow boiling heat transfer with account of the reduced pressure effect
- Blanka Jakubowska
- Stanisław Głuch
- Jan Wajs
- Dariusz Mikielewicz
2019
In the present study the attention was focused on the influence of reduced pressure on the predictions of heat transfer during flow boiling at the extensive range of pressures. The results of calculations were to test the sensitivity of the in-house flow boiling model with respect to the selection of the appropriate two-phase flow multiplier, which is one of the distinctive elements of that model. For this purpose a few two-phase frictional pressure drop correlations were tested. The purpose of this paper is to show that taking into account the effect of the reduced pressure in a model can be of significant importance on the predictions of heat transfer during flow boiling. In the paper are presented the results of calculations using the authors' own model to predict heat transfer coefficient during flow boiling. The model has been tested against a large selection of experimental data collected from various researchers to investigate the sensitivity of the in-house developed model. In the work are presented the results of calculations obtained using the in-house developed semi empirical model on selected experimental flow boiling data of the following refrigerants: R134a, R1234yf, R600a and CO2.
A Set of Experience-Based Smart Synergy Security Mechanism in Internet of Vehicles
- Fei Li
- Haoxi Zhang
- Lulu Gao
- Juan Wang
- Cesar Sanin
- Edward Szczerbicki
2019 CYBERNETICS AND SYSTEMS
In this article, we introduce a novel security mechanism, the Smart Synergy Security (3S). The mechanism uses the Set of Experience Knowledge Structure (SOEKS) and the synergy of security methods in different domains to provide the global optimal security strategy. The proposed strategy is taking into account the characteristics of information security (i.e. confidentiality, integrity, availability, controllability, and reviewability) imposed in different domains in Internet of Vehicles (IoV). The SOEKS is used to represent knowledge, and is combined with the data flow in each domain. Initial experiments demonstrate that the proposed approach is able to find the optimal solution under different conditions for multi-domain security problems in IoV.
A Simple-Topology Compact Broadband Circularly Polarized Antenna With Unidirectional Radiation Pattern
- Ubaid Ullah
- Sławomir Kozieł
- Ismail Mabrouk
2019 Pełny tekst IEEE Antennas and Wireless Propagation Letters
In this letter, a geometrically simple, reflector-backed single-point-fed circularly polarized (CP) antenna with unidirectional radiation pattern is presented. The structure comprises a simple coplanar waveguide (CPW) feeding circuit with an open slot etched on one side of the coplanar ground. The enhanced CP bandwidth is obtained by combining the loop mode, the slot mode, and the asymmetrical configuration of the coplanar ground planes along the feed line. All parameters are optimized at the full-wave level of description for the best impedance and axial ratio (AR) bandwidth. The antenna footprint is only 0.35 λo×0.39 λo at the lowest CP operating frequency of 3.1 GHz. The measurement results indicate 82% impedance bandwidth (from 3 GHz to 7.2 GHz), and 80% AR bandwidth (from 3.1 GHz to 7.2 GHz). A unidirectional right-hand circular polarization (RHCP) radiation pattern in the +z-direction is also achieved by adding a reflector. The peak realized gain of the antenna is 6.7 dBic, and the peak radiation efficiency is 98%.
A Simplified Method of Trend Removal to Determine Noise Observed During a Supercapacitor’s Discharging
- Łukasz Lentka
- Janusz Smulko
2019 Pełny tekst FLUCTUATION AND NOISE LETTERS
In this paper, new method of trend removal is proposed. This is a simplified method based on Empirical Mode Decomposition (EMD). The method was applied for voltage time series observed during supercapacitor discharging process. It assured the determination of an additive noise component after subtracting the identified trend component. We analyzed voltage time series observed between the terminals of the supercapacitor when discharged by a loading resistance R. The steps of the proposed method are presented in detail. The results are compared with the results obtained for polynomial approximation. Statistical parameters (kurtosis, skewness) of the histograms of the identified noise component were estimated to evaluate the quality of the proposed detrending method. The method was adjusted to the analyzed data by selecting a parameter of the applied envelope function of the EMD method. We conclude that the proposed method is faster and more efficient for detecting the additive noise component than the competitive polynomial approximation. The identified noise component may be used to evaluate the State of Health of tested supercapacitors and therefore requires fast algorithms with efficient detection.
A study of a compact high-efficiency zero-emission power plant with oxy-fuel combustion
- Paweł Ziółkowski
- Janusz Badur
2019
This paper discusses the application of global trends in gas cycles technology using oxy-fuel combustion. This is followed by a demonstration of a design solution for a new cycle with two enhanced energy-converting devices, namely a wet combustion chamber and a spray-ejector condenser. The proposed gas and steam cycle unit is contained within a single turbine, whose benefits combine those offered by gas turbines (high inlet temperatures) and steam turbines (full expansion into a vacuum). The efficiency of the oxy-fuel combustion system with carbon dioxide capture was determined based on thermodynamic analyses carried out using in-house codes (COM-GAS). The motivation behind this research paper was provided by calls for diversification in the power generation industry in Poland as well as the need for new solutions in power plants, including compact ones. Compactness can be achieved when the plant is rid of its largest components such as the heat recovery steam generator and the conventional steam condenser. For this, it would be necessary to design non-standard cutting-edge devices, but the counterbalancing pay-off would be in their size, reduced to the point where power plants, in which they are installed, will be able to adequately address the needs of urban users and cater for heat production demand. The concept under consideration is based on the use of shale gas deposits in the place of extraction in a compact, zero-emission gas-steam turbine power system. In our case power plant compactness is achieved by using two new devices, namely: 1) a wet combustion chamber (with oxy-combustion and combustion chamber walls cooling by thermal transpiration); 2) a condenser spray-ejector (using a bulk condensation of vapor-gas). The main aim of the spray-ejector condenser is simultaneously condensing steam and compressing CO2 from the condensation pressure to about 1 bar. Hence, the most important innovation of this steam-gas cycle emerges as the enhanced condensation, which is based on the nano-injection of cold water and a jet-powered compression of CO2 performed in the spray-ejector condenser.