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Gdańsk University of Technology

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  • A New Approach for Investigating the Impact of Pesticides and Nutrient Flux from Agricultural Holdings and Land-Use Structures on Baltic Sea Coastal Waters
    • Lidia Dzierzbicka-Głowacka
    • Maciej Janecki
    • Dawid Dybowski
    • Beata Szymczycha
    • Hanna Obarska-Pempkowiak
    • Ewa Wojciechowska
    • Piotr Zima
    • Stefan Pietrzak
    • Grażyna Pazikowska-sapota
    • Beata Jaworska-Szulc
    • Artur Nowicki
    • Żaneta Kłostowska
    • Adam Szymkiewicz
    • Katarzyna Galer-Tatarowicz
    • Marcin Wichorowski
    • Michał Białoskórski
    • Tadeusz Puszkarczuk
    2019 Full text POLISH JOURNAL OF ENVIRONMENTAL STUDIES

    Knowledge related to land-use management impacts on the Baltic Sea ecosystem is limited. The constant release of pollutants into water bodies has resulted in water quality degradation. Therefore, only the innovative approaches integrated with research will provide accurate solutions and methods for proper environment management and will enable understanding and prediction of the impacts of land-use in the Baltic Sea region. Modelling approaches have become essential to address water issues and to evaluate ecosystem management. There are many water quality models, but only a few work in the operational mode and only some of them can be used as an interactive tool for environmental management to assess the impact of pollution on water quality. This study presents a new approach for investigating the influence of pesticides and nutrient fluxes from agricultural holdings and land-use structures on coastal waters of the Baltic Sea. Called WaterPUCK, this method will enable calculation of the sufficient amount of fertilizers, investigation nutrients, and pesticide sources and model: the fate and distribution of nutrients and pesticides in the surface water and groundwater; loads of pollution to surface water and groundwater; fluxes of nutrients via submarine groundwater discharge (SGD) to the Baltic Sea coastal environment; the processes and mechanisms influencing the persistence of nutrients in the environment; and predict the changes in land use and climate change influence on the Bay of Puck ecosystem.

  • 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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 Full text 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.

  • A Study of Transport Behaviour of Academic Communities
    • Aleksandra Romanowska
    • Romanika Okraszewska
    • Kazimierz Jamroz
    2019 Full text Sustainability

    An important challenge to achieving sustainable university campuses is ensuring that the academic community makes sustainable transport choices. The objective of this study was to investigate the daily commuting patterns, identify the potential for change, and determine the factors and criteria affecting the transport decisions of academic communities of two universities located in Gdansk, Poland. This paper summarizes the results of trip generation measurements and a comprehensive online survey of 3678 respondents, including the universities’ staff and students. Analysis of survey results revealed clear differences between students and university staff in terms of travel patterns and factors that influence their choices. Staff usually (57%) choose the car for daily commutes with students opting for public transport (59%). The choice of travel mode in particular groups is determined mostly by car availability, trip origin location, and accessibility. The choices also depend on transport user individual requirements such as trip quality, costs, or ecology. With approximately 1400 trips daily per 1000 students, the universities are large traffic generators. Thus, how the staff and students behave determines the effect the universities have on the urban transport system. Understanding the behaviour can help to estimate whether it can be changed and how.

  • A three-dimensional periodic beam for vibroacoustic isolation purposes
    • Arkadiusz Żak
    • Marek Krawczuk
    • Grzegorz Redlarski
    • Łukasz Doliński
    • Slawomir Koziel
    2019 Full text MECHANICAL SYSTEMS AND SIGNAL PROCESSING

    This paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequency band gaps that are present in the frequency spectrum of the beam. Since the dynamic behaviour of the beam is directly related to its geometry, through an optimisation process of the beam geometry, desired dynamic characteristics of the beam were successfully obtained. For the purpose of the optimisation process a new numerical model of the beam, based on the spectral finite element method in the time domain (TD-SFEM), was developed by the authors. This model enabled the authors to investigate the beam behaviour not only in a wide frequency spectrum, but also ensured a high accuracy of the model predictions. The accuracy of this modelling approach was checked against well-known analytical formulas. However, in the case of the optimised geometry of the beam for the verification of the correctness of the modelling approach a commercial finite element method (FEM) package was used. Finally, based on the results of numerical predictions and optimised geometry of the beam a sample for experimental verification was prepared.Experimental measurements were carried out by the authors by the application of one-dimensional (1-D) laser Doppler scanning vibrometry (LDSV). The results of experimental measurements obtained by the authors confirmed the correctness of the numerical predictions, showing a high degree of correspondence.

  • A Three-Step Approach to Estimation of Reduction Potentials of Natural Mixtures of Antioxidants Based on DPPH Test; Illustration for Catechins and Cocoa
    • Barbara Kusznierewicz
    • Monika Baranowska
    • Klaudia Suliborska
    • Wojciech Chrzanowski
    • Jacek Namieśnik
    • Agnieszka Bartoszek-Pączkowska
    2019 Full text Proceedings

    The aim of this study is to propose a methodology to assess electrochemical properties of complex mixtures of antioxidants, such as plant extracts, based on the results of simple and popular DPPH test. The first, most difficult step, involves determinations of standard reduction potentials (E0) for the series of purified compounds (here catechins). The next step is the calculation of stoichiometric values (n10) based on the results of DPPH test for the same compounds. Finally, a correlation equation is formulated, which is then employed to estimate “cumulative reduction potential” (Ec) for the mixture of interest (here cocoa) using DPPH test results.

  • A unified approach to the analysis of electric energy and fuel consumption of cars in city traffic
    • Jacek Kropiwnicki
    2019 ENERGY

    Forecasting fuel and electricity consumption is an important factor determining the direction of changes in road engineering solutions, traffic management, selection of routes for public transport and development more efficient car drive systems. With a reliable and easy-to-use computational tool, it is possible to reduce the consumption of primary energy sources and reduce the emission of toxic compounds in cities. An analysis of the impact of the selected variables describing traffic conditions on the fuel consumption has been included in this work, as well as the influence of the drive system hybridization. On this basis, the original, high accuracy fuel consumption model for the road-averaged input data has been presented, which enables taking into account the up-to-date traffic conditions. The presented in this paper model of the fuel consumption has been also extended for the regenerative braking systems. The final results of the analysis showed that modelling of the fuel and the energy consumption (including electric drives) of vehicles in city traffic, with an expected accuracy of 5%, can be successfully made using 5 specified variables describing traffic conditions. The original method of the input data collection, from the real world traffic, has been also presented.

  • A Wearable System Developed to Monitor People Suffering from Vasovagal Syncope
    • Michał Pietrewicz
    • Artur Poliński
    • Tomasz Kocejko
    • Jerzy Wtorek
    2019 Full text

    A wearable system for monitoring non-invasively signals invaluable when examining person suffering from vasovagal syncope is presented in the paper. Following signals are continuously recorded: electrocardiogram, photopletysmogram, impedance cardiogram and electrodermal resistance.

  • A Wideband Corrugated Ridged Horn Antenna with Enhanced Gain and Stable Phase Center for X- and Ku-Band Applications
    • Manshari Saeed
    • Sławomir Kozieł
    • Leifur Leifsson
    2019 IEEE Antennas and Wireless Propagation Letters

    In this letter, a structure and design procedure of a novel double-flared conical horn antenna with an improved gain and a stable phase center is presented. The antenna incorporates a hybrid ridged and corrugated structure. A double-ridged section is responsible for ensuring a wideband operation, whereas the corrugated section supports the hybrid mode. The antenna impedance bandwidth (VSWR < 2) is 6 GHz to 20 GHz. Excellent performance is demonstrated for both the X and Ku bands. In particular, the antenna exhibits 12 dBi to 18 dBi gain over both operating bands, a constant 44-degree, 10-dB beamwidth radiation pattern over the Ku band and a close-to-constant 65-degree beamwidth over the X band. The design is validated using both numerically and experimentally. The measurement and simulation indicate that the phase center variation in the X and the Ku bands is less than 2 cm and 1.5cm, respectively.

  • Abandoned heritage – the first European airports
    • Agnieszka Szuta
    2019 Full text Czasopismo Techniczne

    Due to the development of air transport and urban expansion, the locations of pre-war airports were often changed. The question of the fate of the abandoned airports and their entire infrastructure arose. This article looks at the issue of derelict, pre-war airfields. Examples of airports which were successfully adapted as well as the ones which were abandoned and closed yet but equally important in historical context are shown. In this paper, alternative possibilities for using the former civil airports which allowed memory of important, historical events to be honoured are shown as well as benefits of their preservation are presented.

  • About the Noether’s theorem for fractional Lagrangian systems and a generalization of the classical Jost method of proof
    • Jacky Cresson
    • Anna Szafrańska
    2019 Fractional Calculus and Applied Analysis

    Recently, the fractional Noether's theorem derived by G. Frederico and D.F.M. Torres in [10] was proved to be wrong by R.A.C. Ferreira and A.B. Malinowska in (see [7]) using a counterexample and doubts are stated about the validity of other Noether's type Theorem, in particular ([9],Theorem 32). However, the counterexample does not explain why and where the proof given in [10] does not work. In this paper, we make a detailed analysis of the proof proposed by G. Frederico and D.F.M. Torres in [9] which is based on a fractional generalization of a method proposed by J. Jost and X.Li-Jost in the classical case. This method is also used in [10]. We first detail this method and then its fractional version. Several points leading to difficulties are put in evidence, in particular the definition of variational symmetries and some properties of local group of transformations in the fractional case. These difficulties arise in several generalization of the Jost's method, in particular in the discrete setting. We then derive a fractional Noether's Theorem following this strategy, correcting the initial statement of Frederico and Torres in [9] and obtaining an alternative proof of the main result of Atanackovic and al. [3]

  • Acceleration of the Discrete Green’s Function Formulation of the FDTD Method Based on Recurrence Schemes
    • Jacek Gulgowski
    • Tomasz Stefański
    2019 Full text

    In this paper, we investigate an acceleration of the discrete Green's function (DGF) formulation of the FDTD method (DGF-FDTD) with the use of recurrence schemes. The DGF-FDTD method allows one to compute FDTD solutions as a convolution of the excitation with the DGF kernel. Hence, it does not require to execute a leapfrog time-stepping scheme in a whole computational domain for this purpose. Until recently, the DGF generation has been the limiting step of DGF-FDTD due to large computational resources, in terms of processor time and memory, required for these computations. Hence, we have derived the no-neighbours recurrence scheme for one-dimensional FDTD-compatible DGF using solely properties of the Gauss hypergeometric function (GHF). Using known properties of GHF, the recurrence scheme is obtained for arbitrary stable time-step size. In this paper, we show that using the recurrence scheme, computations of 1-D FDTD solutions with the use of the DGF-FDTD method can be around an order of magnitude faster than those based on the direct FDTD method. Although 2- and 3-D recurrence schemes for DGF (valid not only for the magic time-step size) still need to be derived, the 1-D case remains the starting point for any research in this area.

  • Accuracy assessment of mobile satellite measurements in relation to the geometrical layout of rail tracks
    • Cezary Specht
    • Władysław Koc
    • Piotr Chrostowski
    • Jacek Szmagliński
    2019 Full text Metrology and Measurement Systems

    The paper presents the campaigns of mobile satellite measurements, carried out in 2009–2015 on the railway and tram lines. The accuracy of the measurement method has been analysed on the basis of the results obtained in both horizontal and vertical planes. The track axis deviation from the defined geometric shape has been analysed in the areas clearly defined in terms of geometry, i.e. on the straight sections and sections with constant longitudinal inclination. The values of measurement errors have been estimated on the basis of signals subjected to appropriate processes of filtration. The paper attempts to evaluate the changing possibilities of using the GNSS techniques to determine the shape of the railway track axis from 2009 to 2015. The determined average value of the measurement error now equals a few millimetres. This achievement is very promising for the prospects of mobile satellite measurements in railway engineering.

  • Action Research - przygotowanie sądu do zmiany poprzez uczenie się - współpraca praktyków i badaczy
    • Przemysław Banasik
    • Sylwia Morawska
    2019 Full text e-mentor

    W praktyce zarządzanie sądem na ogół jest oddalone od teorii zarządzania. Prezesi sądów rzadko zwracają się do naukowców z prośbą o rozwiązanie ich problemów w zarządzaniu. W sądach brakuje nie tylko stałych form współpracy z naukowcami zajmującymi się zarządzaniem, ale także z innymi interesariuszami. Jedyną formą komunikacji, i to z ograniczoną liczbą interesariuszy, są formalne środki wyznaczone przez procedurę cywilną lub karną. To powoduje, że sądy postrzegane są jako organizacje hermetyczne. W praktyce funkcjonowania sądu pojawił się problem w nawiązaniu relacji z jego interesariuszami, czy też szerzej - wdrożenia zasad związanych z koncepcją społecznej odpowiedzialności organizacji (dalej CSR). Konieczna stała się, w pierwszej kolejności, identyfikacja interesariuszy sądu, ich hierarchizacja oraz wskazanie obszarów i form możliwej współpracy. Zaistniało zapotrzebowanie na naukowe porady z zakresu zarządzania. Sądy nie miały doświadczenia w identyfikowaniu, mapowaniu interesariuszy i przyporządkowaniu dla poszczególnych rodzajów interesariuszy nieformalnych, pozaproceduralnych form współpracy. Jedną z prób poradzenia sobie z tymi problemami przy zachowaniu najwyższych rygorów naukowych stało się wykorzystanie Action Research. Jest to podejście, które: traktuje wiedzę badacza jako równie ważną jak wiedza aktorów społecznych; ma na celu rozwiązywanie praktycznych problemów organizacyjnych; a także jest neutralne względem podziałów paradygmatycznych na metody ilościowo-jakościowe (celem jest rozwiązanie problemu praktycznego, badacz wykorzystuje te narzędzia, które akurat okażą się przydatne). Przykład Sądu Okręgowego w Gdańsku pokazał, że możliwa jest współpraca praktyków i badaczy w rozwiązaniu konkretnego problemu poprzez wykorzystanie strategii badawczej Action Research (AR). Badaniem objęto horyzont czasowy między czerwcem 2013 roku a marcem 2018 roku, czyli okres prawie 5 lat. Analiza wyników badań pokazuje, że po pierwsze, AR może być wykorzystany w organizacjach publicznych, a po drugie, interwencja w wyniku wykorzystania tej metody badawczej jest skuteczna. W wyniku współpracy praktyków i teoretyków opracowano i wdrożono praktykę zarządczą "Sąd zaangażowany społecznie". Udział praktyków sądowych w jej tworzeniu wygenerował zaufanie do jej praktycznego charakteru wśród innych sądów i zapewnił zapotrzebowanie na jej wdrożenie.

  • Action Research: Cooperation of Practitioners and Researchers for Knowledge Development in Public Organisations
    • Przemysław Banasik
    • Sylwia Morawska
    2019

    Action Research (AR) is not only a research method or a research strategy for solving a research problem, but also an effective tool for developing knowledge and implementing changes in the organization. The aim of AR is to bring about a change within the studied area and get participants to initiate changes, in which the researcher and the recipient collaborate in investigating the problem and developing a relevant solution. AR assumes the collaboration of researchers, practitioners and laymen, and consists in systematically collecting data from everyday practice and analyzing it in order to decide on its future shape. The AR study was conducted in a public organization, namely the District Court in Gdańsk. The subject of the AR study was extrajudicial activities – pro-social activities undertaken by the District Court in Gdańsk. The study was to answer the question whether public organizations – in this case, courts - can engage in pro-social activities, and if so, in which areas. The study covered the time horizon between June 2013 and March 2018, that is, a period of over five years. As part of the conducted research, successive observations of the phenomena taking place within the organization were carried out, and so were a number of interviews with the court's management, conversations with various groups of stakeholders and quantitative surveys with stakeholders on the subject of collaboration with the court and its quality. Analysis of research results shows, first, that AR can be used in public organizations, and second, that intervention resulting from the use of this research method is effective. Despite changes in management and political changes, pro-social activities are still being undertaken in courts, having become an organizational routine. Research findings additionally supplement the current knowledge about the possibility of undertaking pro-social activities by public organizations, including courts. They fall within the scope of strategic management in the subdiscipline of public management

  • Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-D-galactosidase from Arthrobacter sp. 32cB
    • Maria Rutkiewicz
    • Anna Bujacz
    • Marta Wanarska
    • Anna Wierzbicka-Woś
    • Hubert Cieśliński
    2019 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    ArthbetaDG is a dimeric, cold-adapted beta-D-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The resulting three-dimensional structures of complexes: ArthbetaDG_E441Q/LACs and ArthbetaDG/IPTG (ligand bound in shallow mode) and structures of complexes ArthbetaDG_E441Q/LACd, ArthbetaDG/ONPG (ligands bound in deep mode), and galactose ArthbetaDG/GAL and their analysis enabled structural characterization of the hydrolysis reaction mechanism. Furthermore, comparative analysis with mesophilic analogs revealed the most striking differences in catalysis mechanisms. The key role in substrate transfer from shallow to deep binding mode involves rotation of the F581 side chain. It is worth noting that the 10-aa loop restricting access to the active site in mesophilic GH2 betaDGs, in ArthbetaDG is moved outward. This facilitates access of substrate to active site. Such a permanent exposure of the entrance to the active site may be a key factor for improved turnover rate of the cold adapted enzyme and thus a structural feature related to its cold adaptation.

  • Activity of isavuconazole and other triazole derivatives against clinical isolates of Aspergillus fumigatus
    • Urszula Nawrot,
    • Katarzyna Włodarczyk,
    • Marzenna Bartoszewicz,
    • Sylwia Balicka,
    • Monika Pomorska-wesołowska,
    • Ewelina Kurzyk
    • Anna Brillowska-Dąbrowska
    • Beata Sulik-tyszka
    • Grzegorz Basak
    • Marta Wróblewska
    2019 Postępy Higieny i Medycyny Doświadczalnej

    Aspergillus fumigatus is the most frequent pathogen of the genus Asperillus, which is highly susceptible to triazole derivatives, especially to isavuconazole and voriconazole. Many countries face a growing problem of infections due to A. fumigatus showing acquired resistance to one or several triazoles. In medical centres, monitoring the susceptibility of isolated Aspergillus spp. is recommended. The aim of this study was to collect and test triazole susceptibility of Aspergillus fumigatus obtained from clinical samples, which were investigated in diagnostic laboratories located in Wrocław, Warszawa and Ruda Śląska (Poland). In addition, 5 resistant A. fumigatus strains with TR34/L98H mutation were included. The microdilution method, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was applied to test susceptibility to isavuconazole (ISV), voriconazole (VOR), posaconazole (POS) and itraconazole (ITR). During a period of 24 months, a total number of 75 A. fumigatus isolates were collected. Most of the strains were obtained from lower respiratory tract specimens (58/75; 77%), from patients hospitalized on pulmonology (41%) or intensive care and surgery units (29%). No isolate resistant to ISV or other triazoles was found. The minimal inhibitory concentration (MIC) value of ISV ranged from 0.125 to 1 mg/L (mean 0.4 ±0.15 mg/L) in triazole susceptible isolates, whereas among triazole-resistant strains, three showed a MIC of 8 mg/L and two had a MIC of 4 mg/L. A. fumigatus isolates carrying the mutation TR34/L98H are cross-resistant to ISV. The acquired resistance is very rare in our region (0-4%), which supports of use of triazole derivatives (VOR, ISV) in the therapy of aspergillosis.

  • Adaptation of radar software to work with ambiguous distance measurement
    • Kamil Stawiarski
    • Michał Meller
    2019 Full text Proceedings of SPIE

    A software extension for radar stations designed to work in the low-PRF mode that allows them to correctly measure range to targets outside of their instrumented range, is proposed. The solution does not require substantial modifications of the radar software. Additionally, we describe tools that allow one to simulate the output of a low-PRF radar observing targets that are outside its instrumented range. The proposed approach is verified using computer simulations.

  • Adaptation of the arbitrary Lagrange–Euler approach to fluid–solid interaction on an example of high velocity flow over thin platelet
    • Piotr J Ziółkowski
    • Tomasz Ochrymiuk
    • Victor Eremeev
    2019 Full text CONTINUUM MECHANICS AND THERMODYNAMICS

    The aim of this study is to analyse the behaviour of a thin plate with air flow velocities of 0.3–0.9 Ma. Data from the experiment and numerical tools were used for the analysis. For fluid–solid interaction calculations, the arbitrary Lagrange–Euler approach was used. The results of the measurements are twofold. The first one is the measurement of the flow before and after vibrating plate, i.e. pure flow plate, and the second consists in measuring the characteristics of vibration of the plate. The character of the vibration was measured with an oscilloscope, and then the results were subjected to FFT analysis to determine the natural and flow induced vibrations. For numerical calculations example, the velocity of 0.7 Ma was selected. The deflections of the platelet under the influence of airflow were obtained. The trace of the friction layer that forms the boundary between the flow from the platelet and the separation formed behind the platelet.

  • Adsorption of Cr(VI) in aqueous solution using sago bark (Metroxylon sagu) as a new potential biosorbent
    • Syiffa Fauzia
    • Aziz Hermansyah
    • Dahlan Dahyunir
    • Jacek Namieśnik
    • Rahmiana Zein
    2019 Desalination and Water Treatment

    This paper investigated the ability of sago bark (Metroxylon sagu) as a new potential biosorbent in removing Cr(VI) in batch system. The optimum adsorption capacity of sago bark (Metroxylon sagu) was 61.73 mg/g achieved at pH 3, agitation rate of 100 rpm, contact time 60 min, particle size ≤32 μm, and initial concentration of Cr(VI) 1,000 mg/L at room temperature (25°C). The adsorbent regeneration was carried out using 0.01 M HNO3 with regeneration efficiency of 78.35%. The adsorption data fitted better to Freundlich and Langmuir equilibrium isotherm models. The data confirmed that Cr(VI) sorption onto sago bark (Metroxylon sagu) has good agreement with pseudo-second-order model. The thermodynamic study indicated that Cr(VI) sorption onto sago bark (Metroxylon sagu) occurred as exothermic in nature (DH = –72.55 kJ/mol), which was required energy for adsorption process, and the disorderliness decreased as temperature increased (DS = –263.06 J/mol). Thus, it can be concluded that sago bark (Metroxylon sagu) can be utilized as a potential adsorbent in Cr(VI) removal.

  • Adsorption-assisted transport of water vapour in super-hydrophobic membranes filled with multilayer graphene platelets
    • Emilia Gontarek
    • F Macedonio
    • F Militano
    • L Giorno
    • Marek Lieder
    • A Politano
    • E Drioli
    • Annarosa Gugliuzza
    2019 NANOSCALE

    The effects of confinement of multilayer graphene platelets in hydrophobic microporous polymeric membranes are here examined. Intermolecular interactions between water vapour molecules and nanocomposite membranes are envisaged to originate assisted transport of water vapour in membrane distillation processes when a suitable filler-polymer ratio is reached. Mass transport coefficients are estimated under different working conditions, suggesting a strong dependence of the transport on molecular interactions. Remarkably, no thermal polarization is observed, although the filler exhibits ultrahigh thermal conductivity. In contrast, enhanced resistance to wetting as well as outstanding mechanical and chemical stability meets the basic requirements of water purification via membrane distillation. As a result, a significant improvement of the productivity–efficiency trade-off is achieved with respect to the pristine polymeric membrane when low amounts of platelets are confined in spherulitic-like PVDF networks.

  • Advanced Oxidation Processes for the Treatment of Contaminants of Emerging Concern
    • Javed Khan
    • Murtaza Sayed
    • Khan Sanaullah
    • Noor S. Shah
    • Dionysios Dionysiou
    • Grzegorz Boczkaj
    2019

    The application of contaminants of emerging concern (CEC) such as pharmaceuticals and personal care products (PPCPs), pesticides, plasticizers, endocrine disruptors, surfactants, flame retardants and polycyclic aromatic hydrocarbons (PAHs) became an indispensable requirement of the current era. Although the CEC are useful for wide-spectrum purposes, they can also result in undesirable effects on human health and other animals. The large scale use of CEC leads to their ubiquitous occurrence in surface and ground water sources and has caused great concern among the scientific community and regulatory authorities in recent years. Since CEC may have significant adverse effects on human health and other animals including aquatic life, their efficient removal from water bodies is essential. A number of advanced oxidation processes (AOPs) have been developed for the enhanced degradation of CEC. This book chapter focuses on the occurance and possible effects of CEC on human health and other animals. Various AOPs have been discussed in detail and their application for the treatment of CEC have been outlined. The AOPs were divided into three groups namely chemical, photochemical and photocatalytic AOPs. Both hydroxyl and sulfate radicals-driven AOPs were discussed. The experimental results of previously published research papers regarding the removal of CEC have been summarized under each AOP section for better understanding of the effectiveness of these AOPs. The various factors that could affect the performance of these AOPs were taken into account. Furthermore, the cost evaluation of different AOPs is summarized. At the end, some challenges faced by AOPs including the toxic disinfection by-products formation have been highlighted. Finally, future suggestions are recommended for practical applications of these AOPs.

  • Advanced Supervisory Control System Implemented at Full-Scale WWTP—A Case Study of Optimization and Energy Balance Improvement
    • Jakub Drewnowski
    2019 Full text Water

    In modern and cost-eective Wastewater Treatment Plants (WWTPs), processes such as aeration, chemical feeds and sludge pumping are usually controlled by an operating system integrated with online sensors. The proper verification of these data-driven measurements and the control of different unit operations at the same time has a strong influence on better understanding and accurately optimizing the biochemical processes at WWTP—especially energy-intensive biological parts (e.g., the nitrification zone/aeration system and denitrification zone/internal recirculation). In this study, by integrating a new powerful PreviSys with data driven from the Supervisory Control and Data Acquisition (SCADA) software and advanced algorithms such as Model Predictive Control (MPC) by using the WEST computer platform, it was possible to conduct different operation strategies for optimizing and improving the energy balance at a full-scale “Klimzowiec” WWTP located in Chorzow (Southern Poland). Moreover, the novel concept of double-checking online data-driven measurements (from installed DO, NO3, NH4 sensors, etc.) by mathematical modelling and computer simulation predictions was applied in order to check the data uncertainty and develop a support operator system (SOS)—an additional tool for the widely-used in-operation and control of modern andcost-effective WWTPs. The results showed that by using sophisticated PreviSys technology, a better understanding and accurate optimization of biochemical processes, as well as more sustainable WWTP operation, can be achieved.

  • Advances in Architectures, Big Data, and Machine Learning Techniques for Complex Internet of Things Systems
    • David Gil
    • Magnus Johnsson
    • Higinio Mora
    • Julian Szymański
    2019 Full text COMPLEXITY

    Te feld of Big Data is rapidly developing with a lot of ongoing research, which will likely continue to expand in the future. A crucial part of this is Knowledge Discovery from Data (KDD), also known as the Knowledge Discovery Process (KDP). Tis process is a very complex procedure, and for that reason it is essential to divide it into several steps (Figure 1). Some authors use fve steps to describe this procedure, whereas others use only four.

  • Advantages of the Application of the Temper Bead Welding Technique During Wet Welding
    • Jacek Tomków
    • Grzegorz Rogalski
    • Dariusz Fydrych
    • Jerzy Łabanowski
    2019 Full text Materials

    Thermo-mechanically rolled S460ML steel was chosen for welding in underwater wet welding conditions by covered electrodes. The main aim of this study was to check the weldability for fillet welds in a water environment by controlled thermal severity (CTS) tests and to check the influence of temper bead welding (TBW) on the weldability of the investigated steel. Non-destructive and destructive tests showed that S460ML steel has a high susceptibility to cold cracking. In all joints, hardness in the heat-affected zone (HAZ) was extended to the 400 HV10 values. Microscopic testing showed the presence of microcracks in the HAZ of all welded joints. TBW was chosen as the method to improve the weldability of the investigated steel. This technique allows for the reduction of the maximum hardness in the HAZ below the critical value of 380 HV10, as stated by the EN-ISO 15614-1:2017. It was determined that for S460ML steel, from the point of view of weldability, the pitch between two beads should be in the range 75%-100%. Also, if the pitch between two beads increases, the hardness, grain size, and number of cracks decreases. In all specimens where the hardness of the HAZ was below 380 HV10, there were no microcracks.

  • AEGIS – mobilne urządzenie do wytwarzania kurtyny elektromagnetycznej dla zastosowań specjalnych i ochrony przed RCIED
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Magiera
    • Paweł Tomasz Kosz
    • Agnieszka Czapiewska
    • Robert Burczyk
    • Jarosław Sadowski
    • Sławomir Ambroziak
    2019 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono założenia, projekt oraz wykonanie demonstratora technologicznego mobilnego urządzenia do wytwarzania kurtyny elektromagnetycznej. Urządzenie jest zaprojektowane do zablokowania łączności radiowej, za pomocą której możliwe byłoby zdetonowanie prowizorycznych ładunków wybuchowych. Celem jest zapewnienie bezpieczeństwa funkcjonariuszom służb państwowych takich jak Straż Graniczna, czy też Policja. W artykule zarówno przedstawiono urządzenie, jak i omówiono oprogramowanie demonstratora technologicznego, dzięki któremu możliwe jest wytworzenie szerokopasmowego sygnału zagłuszającego

  • Aeration Process in Bioreactors as the Main Energy Consumer in a Wastewater Treatment Plant. Review of Solutions and Methods of Process Optimization
    • Jakub Drewnowski
    • Anna Remiszewska-Skwarek
    • Sylwia Duda
    • Grzegorz Łagód
    2019 Full text Processes

    Due to the key role of the biological decomposition process of organic compounds in wastewater treatment, a very important thing is appropriate aeration of activated sludge, because microorganisms have to be supplied with an appropriate amount of oxygen. Aeration is one of the most energy-consuming processes in the conventional activated sludge systems of wastewater treatment technology (may consume from 50% to 90% of electricity used by a plant), which makes it the most cost-generating process incurred by treatment plants. The paper presents the construction of aeration systems, their classification as well as parameters and factors that significantly affect the aeration process e.g., oxygen transfer effciency, diffuser fouling, methods of dealing with diffuser fouling, diffuser selection. Additionally, there are briefly presented “smart control” systems in wastewater treatment and effect of application control strategy based on Supervisory Control and Data Acquisition system connected with the decrease in the energy consumption for aeration of bioreactors with activated sludge. It is noted that before the process is optimized, the system should be equipped with suitable metering devices. Only when relevant data is available, the improvements can be carried out. However, it’s important, that the operator should regularly maintain good condition and high effciency of diffusers.

  • Aerodynamics in the education of prospective architects
    • Katarzyna Zielonko-Jung
    2019 Full text World Transactions on Engineering and Technology Education

    The inclusion of issues of aerodynamics in the education of architecture students is discussed in this article. The field of aerodynamics knowledg of the nature of wind phenomena around building developments. It is especially important to know how to influence the occurrence of such phenomena by means of shaping buildings through architectural and urban design. The method applied for working with Master’s degree students in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT), Gdańsk, Poland, included experimental studies in a wind tunnel. The technique allows prospective architects not only to become acquainted with a specific issue that ranges beyond their competencies, but also to attain a broader perspective on the interdisciplinary nature of building residential estates and on city design.

  • Airstrip Ground Improvement Works by Blasting Charge Technique and Dredged-Ash Material Mixture
    • Eligiusz Mieloszyk
    • Mariusz Wyroślak
    2019 Full text IOP Conference Series: Materials Science and Engineering

    Soil improvement by blasting charge technique is known in geotechnics as one of the efficient and inexpensive method. It can be used in preparing of underground to found road construction and buildings as well. The technique proves usefulness especially when dynamic load is applied. It is because of non-stiff or rather resilient type soil after improvement. In noncohesive or organic soil, blasting charge must be used with well-graded soil or similar granular material layered as working platform. Explosions cause exchange of soil. Using dredged-ash material mixture it can be benefitable in resource management and ecology. The purpose of research was finding a fast method of soil improvement to prepare special constructions like airstrips for landing and taking off light and small aircrafts. Expected results can be achieved after using blasting charge technique.

  • Aktywizacja potencjału mieszkańców miast polskich poprzez działania artystyczne w oparciu o wybrane przykłady
    • Anna Stasiak
    2019 Full text Acta Scientiarum Polonorum Administratio Locorum

    Obecnie ponad połowa mieszkańców naszego globu zamieszkuje tereny zurbanizowane. Doprowadziło to do wyraźnego zagęszczenia ludności w miastach w przeciągu kilku ostatnich dziesięcioleci, a tym samym zmienił się tryb życia ich mieszkańców. W wielotysięcznych miastach coraz trudniej jest znaleźć pretekst i możliwość do nawiązania bliższych relacji z otaczającymi nas ludźmi. Działania artystyczne związane z tworzeniem i prezentowaniem sztuki w przestrzeniach publicznych są jedną z dróg pozwalających na aktywizację potencjału mieszkańców miast. Celem artykułu jest poprzez analizę pięciu drobnoskalowych aktywności artystycznych zdefiniowanie zabiegów przestrzennych, dzięki którym można osiągnąć pozytywne efekty – uspołeczniające oraz estetyzujące przestrzeń.

  • Akustyczna analiza natężenia ruchu drogowego dla systemów zarządzania ruchem
    • Karolina Marciniuk
    2019

    W pracy przybliżono wybrane zagadnienia z dziedziny zarządzania transportem drogowym w Polsce i na świecie. W tym kontekście pzredstawiono potrzeby rynkowe, wymagania jak i możliwości w zakresie pozyskiwania informacji o aktualnym stanie sieci drogowych. Zaproponowano akustyczną metodę nadzorowania ruchu drogowego i jej możliwości w kontekście systemów zarządzania ruchem. Przedstawiono schemat akwizycji sygnału wraz z danymi odniesienia. Omówiono proces opracowywania bazy danych i metodykę procesów związanych z przetwarzaniem wstępnym sygnałów audio. Następnie przedstawiono proces selekcji parametrów użytych do detekcji obecności pojazdu. Wykryte zdarzenia poddawane były ocenie statystycznej związanej z odstępami między pojazdami (kryterium bezpiecznej odległości), a następnie przeprowadzono dokładniejszą klasyfikację. Przedstawiono metody klasyfikacji typów pojazdów na podstawie ich brzmienia, stosując podział na cztery typy pojazdów, zestawiając to z typowymi stosowanymi metodami klasyfikacji w systemach zarządzania ruchem. Dodatkowo przestawiono metodę oceny bezpieczeństwa ruchu związanej z przyczepnością pojazdu do nawierzchni drogi – poprzez akustyczne wykrywanie obecności wody i śniegu na jezdni.

  • Akustyczne zobrazowanie morskich osadów dennych
    • Wojciech Szymczak
    2019 Full text

    Przedstawiany temat rozprawy doktorskiej: „Akustyczne zobrazowanie morskich osadów dennych”, prezentuje metody zobrazowania struktury osadów dennych pozyskanych z sondowania akwenu echosondą parametryczną SES-2000 Standard oraz urządzeniami pomocniczym — echosondą wielowiązkową EM3002 i sonarem bocznym. Tezą jest wykazanie, że metody akustyczne dają możliwość bezinwazyjnej klasyfikacji osadów dennych. Hipoteza zakłada, że istnieje ścisły związek pomiędzy wynikami symulacji echogramów w oparciu o informacje geologiczną (zebrane próbki osadów dennych), wynikami pozyskanymi podczas badań laboratoryjnych oraz pomiarami w warunkach rzeczywistych. W pracy zaprezentowana została podstawowa teoria związana z nieliniowymi właściwościami ośrodka oraz modelami i parametrami geofizycznymi dna morskiego. Rozdział 5 i 6 przedstawia metodykę pomiarów oraz analizę wyników badań przeprowadzonych w warunkach laboratoryjnych i podczas pomiarów In Situ (prezentacja charakterystycznych echogramów z wybranych rejonów Zatoki Puckiej/Gdańskiej). W 7 rozdziale przedstawione zostały wyniki działania oprogramowania z zaimplementowanymi metodami wizualizacji oraz klasyfikacji osadów dennych z wybranego akwenu pomiarowego. Pracę zakończono podsumowaniem wskazującym między innymi najważniejsze samodzielne osiągnięcia naukowe autora.