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  • A three-dimensional periodic beam for vibroacoustic isolation purposes
    • Arkadiusz Żak
    • Marek Krawczuk
    • Grzegorz Redlarski
    • Łukasz Doliński
    • Slawomir Koziel
    2019 Pełny tekst 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 Pełny tekst 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 Pełny tekst

    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 Pełny tekst 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 Pełny tekst

    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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst

    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.

  • Akwarela / Watercolour
    • Jacek Krenz
    2019

    katalog dorocznej wystawy Stowarzyszenia Akwarelistów Polskich prezentowanej w Galerii Muzeum regionalnego w Radomsku oraz w Muzeum Miasta Turku im. J. Mehoffera 11.2019. Stowarzyszenie Akwarelistów Polskich 2019,

  • Akwarelą pod strzechy. Krenz J.: Cykl 5 akwarel.
    • Jacek Krenz
    2019

    Akwarelą pod strzechy. wystawa zbiorowa, poplenerowa Stowarzyszenia Akwarelistów Polskich prezentowana w Muzeum - Kaszubski Park Etnograficzny im. Teodory i Izydora Gulgowskich we Wdzydzach Kiszewskich.

  • Algorytmy roju w modelowaniu MES, czyli jak stado szpaków może pomóc inżynierowi
    • Marek Galewski
    • Michał Mazur
    2019 Pismo PG

    W poprzednich numerach „Pisma PG” prof. Jacek Rumiński przedstawił możliwości i perspektywy rozwoju sztucznej inteligencji (SI), zwłaszcza w kontekście notujących obecnie liczne sukcesy sztucznych sieci neuronowych. Jednak nie tylko budowa układu nerwowego jest inspiracją dla nowych metod SI. Ciekawą grupą metod są algorytmy wzorujące się na zachowaniu zwierząt, zwłaszcza na ich zdolnościach socjalnych i współpracy przy stawianiu czoła napotykanym przeciwnościom. Okazuje się, że inspiracje te mogą się przydać np. do ulepszania modeli wykorzystywanych w klasycznych metodach obliczeniowych, takich jak choćby stosowana w inżynierii mechanicznej (i nie tylko) Metoda Elementów Skończonych.

  • Alternative methods for dark fermentation course analysis
    • Edyta Słupek
    • Karolina Kucharska
    • Jacek Gębicki
    2019 Pełny tekst SN Applied Sciences

    Dark fermentation course analysis is crucial, as complexed matrix of gaseous components may be formed and revealed during the process. The paper considers key issues related to the microbiological process in which complex organic substances are transformed into hydrogen. For the purposes of hydrogen generation, the application of wastewater mixed sludge pre-treated according to Faloye method (Faloye et al. in Int J Hydrog Energy 38:11765–11773, 2013. https://doi.org/10.1016/j.ijhyd ene.2013.06.129; Int J Hydrog Energy 39:5607–5616, 2014. https ://doi.org/10.1016/j.ijhydene.2014.01.163) was applied. The main risk of by-product formation is related to the presence of methanogens, i.e., Archea, in the sludge. The application of gaseous chromatography confirmed the presence of hydrogen during the initial, lag and log phases of the culture and methane in the late logarithmic death phase of the culture. However, other fermen-tation gaseous products’ presence was not confirmed, as their concentration was under the limit of detection. Therefore, a revision regarding the application of matrix sensors was proposed, and the levels of gases able to be measured using both gas chromatography and matrix sensors were conducted. The criteria of matrix sensors’ selection should include the selectivity not only for the hydrogen, hydrogen sulfide or methane, but also the sensitivity to the response of other gases contained in the mixture—ammonium, carbon dioxide and oxygen. A comprehensive combination of commer-cially available sensors and their applicability for the purposes of dark fermentation course analysis was presented on the basis of the levels of gas concentrations in the generated gas mixture.

  • Alternative treatment approaches of urinary tract infections caused by uropathogenic Escherichia coli strains
    • Beata Zalewska-Piątek
    • Rafał Piątek
    2019 Pełny tekst Acta Biochimica Polonica

    Urinary tract infections (UTIs) are the most widespread and annoying infections affecting millions of people every year annually. The biggest problem of urinary diseases are recurrences, the increasing resistance of uropathogens to commonly used antibiotics, as well as the high health care costs of afflicted persons. Uropathogenic Escherichia coli strains (UPECs) are the most dominant etiologic agent of community-acquired infections of this type. During UTI pathogenesis, UPECs utilize various virulence factors, especially mono- and polyadhesive appendages of the chaperone-usher secretion pathway (CUP) required for adhesion, invasion and biofilm formation. The commonly used antibiotics for UTI treatment are usually effective, but their long-term utility may affect the gut microbiota of treated individuals and cause a selection of drug resistant uropathogenic variants. Due to the increasing resistance of UPEC strains to antibiotics via the evolution of specific defense mechanisms there is a need to develop alternative methods and therapeutic strategies to fight UTIs (vaccines, receptor analogues, pilicides and curlicides, bacterial interference or phagotherapy). Such therapeutic approaches usually target the processes enabling uropathogens to survive within urinary tract and cause recurrent infections.

  • Aluminium in glacial meltwater demonstrates an association with nutrient export (Werenskiöldbreen, Svalbard)
    • Łukasz Stachnik
    • Jacob C. Yde
    • Adam Nawrot
    • Łukasz Uzarowicz
    • Elżbieta Łepkowska
    • Katarzyna Kozak
    2019 HYDROLOGICAL PROCESSES

    The aluminium (Al) cycle in glacierised basins has not received a great deal of attention in studies of biogeochemical cycles. As Almay be toxic for biota, it is important to investigate the processes leading to its release into the environment. It has not yet been ascertained whether filterable Al (passing through a pore size of 0.45 m) is incorporated into biogeochemical cycles in glacierised basins. Our study aims to determine the relationship between the processes bringing filterable Al and glacier-derived filterable nutrients (particularly Fe and Si) into glacierised basins. We investigated theWerenskiöldbreen basin (44.1 km2, 60% glacierised) situated in SWSpitsbergen, Svalbard. In 2011, we collected meltwater from a subglacial portal at the glacier front and at a downstream hydrometric station throughout the ablation season. The Al concentration, unchanged between the subglacial system and proglacial zone, reveals that aluminosilicate weathering is a dominant source of filterable Al under subglacial conditions. By examining the Al:Fe ratio compared with pH and the sulphate mass fraction index, we found that the proton source for subglacial aluminosilicate weathering ismainly associatedwith sulphide oxidation and, to a lesser degree, with hydrolysis and carbonation. In subglacial outflows and in the glacial river, Al and Fe are primarily in the forms of Al(OH)4 - and Fe(OH)3. The annual filterable Al yield (2.7 mmolm-2)was of amagnitude similar to that of nutrients such as filterable Fe (3.0 mmolm-2) and lower than that of dissolved Si (18.5 mmolm-2). Our results show that filterable Al concentrations in meltwater are significantly correlated to filterable and dissolved glacier-derived nutrients (Fe and Si, respectively) concentrations in glaciers worldwide. We conclude that a potential bioavailable Al pool derived from glacierised basins may be incorporated in biogeochemical cycles, as it is strongly related to the concentrations and yields of glacier-derived nutrients.

  • Amides as models to study the hydration of proteins and peptides — spectroscopic and theoretical approach on hydration in various temperatures
    • Aneta Panuszko
    • Michał Nowak
    • Piotr Bruździak
    • Marcin Stasiulewicz
    • Janusz Stangret
    2019 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Interactions with water are one of the key factors which determine protein stability and activity in aqueous solutions. However, the protein hydration is still insufficiently understood. N-methylacetamide (NMA) is regarded as a minimal part of the peptide backbone and the relative simplicity of its structure makes it a good model for studies on protein–water interactions. In this paper, the influence of NMA and N,N-dimethylacetamide (DMA) on surrounding water molecules in a range of temperature (25–75 ◦C) is studied by means of the FTIR spectroscopy. The results of the difference HDO spectra method are compared with the results of theoretical DFT calculations of NMA and DMA aqueous complexes. Both NMA and DMA can be regarded as “structure-makers”, yet their hydration spheres are different. These molecules exhibit a mixed and mutually dependent types of hydration: hydrophilic and hydrophobic. In the case of a NMA molecule that has one methyl group less than DMA, the type of hydrophobic hydration is more important. The DMA hydration sphere is less stable: the interactions between water molecules around the methyl groups are strained. Moreover, the hydration of NMA is much more temperature dependant than in the case of DMA. The source of the differences may be hidden in the N-H· · ·H2O interaction. The delicate nature of water interactions with the peptide block models may be cautiously translated into the much more complicated interactions of proteins with their hydration shells.

  • Amyloid fibril formation in the presence of water structure-affecting solutes
    • Jarosław Wawer
    • Emilia Kaczkowska
    • Jakub Karczewski
    • Marcin Olszewski
    • Danuta Augustin-Nowacka
    • Joanna Krakowiak
    2019 BIOPHYSICAL CHEMISTRY

    The impact of the differently hydrated non-electrolytes (protein structure destabilizers) on the fibrillation of hen egg white lysozyme (HEWL) was investigated. Two isomeric urea derivatives i.e. butylurea (BU) and N,N,N′,N′-tetramethylurea (TMU) were chosen as a tested compounds. The obtained results show that butylurea exerts greater impact on HEWL and its fibrillation than tetramethylurea. Both substances decrease the time of induction of the fibrillation (lag time) but only BU increases the efficiency of amyloidogenesis. For the systems with equivalent reduction of the HEWL stability (250 mM BU and 500 mM TMU) the not-equivalent increase of the protein fibrillation was recorded (higher for BU). This fact suggests that specific interactions with protein, possibly water mediated, are responsible for the action of the tested substances.

  • An Analysis of Neural Word Representations for Wikipedia Articles Classification
    • Julian Szymański
    • Nathan Kawalec
    2019 CYBERNETICS AND SYSTEMS

    One of the current popular methods of generating word representations is an approach based on the analysis of large document collections with neural networks. It creates so-called word-embeddings that attempt to learn relationships between words and encode this information in the form of a low-dimensional vector. The goal of this paper is to examine the differences between the most popular embedding models and the typical bag-of-words (BoW) approach used for document representation. The hypothesis behind the experiments is that the more informative the representation is, the better classification results it produces. The evaluation of the representations has been performed with regards to the accuracy of three text classifiers. The experiments have been performed on subsets of articles selected from Wikipedia. To test the independence of the results from the language of their dataset, we created datasets for the Polish and English versions of this repository. The datasets have been provided publicly to create a baseline to study the different representation methods. The classification tasks, which aim to reconstruct the human-made Wikipedia categories, confirm that the word embeddings can be successfully used for text classification. Word embeddings for document representation with typical vector averaging methods does not outperform usage of BoW. We use a modification of the document representation based on kernel transformations that shows an improvement of the text classification results. Also, we find that in most cases the method of dimensionality reduction with neural embeddings outperforms that of LSA.

  • An Attempt to Create Speech Synthesis Model That Retains Lombard Effect Characteristics
    • Grazina Korvel
    • Olga Kurasova
    • Bożena Kostek
    2019 Pełny tekst

    The speech with the Lombard effect has been extensively studied in the context of speech recognition or speech enhancement. However, few studies have investigated the Lombard effect in the context of speech synthesis. The aim of this paper is to create a mathematical model that allows for retaining the Lombard effect. These models could be used as a basis of a formant speech synthesizer. The proposed models are based on dividing the speech signal into harmonics and modeling them as the output of a SISO system whose transfer function poles are multiple, and inputs vary in time. An analysis of the Lombard effect of the synthesized signal is performed on the noise residual. The synthesized signal residual is described by vectors of acoustic parameters related to the Lombard effect. For testing the performance of the created models in various noise conditions two classifiers are employed, namely kNN and Naive Bayes. For comparison of results, we created models of sinusoids based on frequency tracks. The results show that a model based on the residual sinewave sum demonstrates the possibility of retaining the Lombard effect. Finally, future work directions are outlined in conclusions.

  • An energetic analysis of a gas turbine with regenerative heating using turbine extraction at intermediate pressure - Brayton cycle advanced according to Szewalski's idea
    • Paweł Ziółkowski
    • Janusz Badur
    • Piotr Ziółkowski
    2019 ENERGY

    In this paper, a modification of a simple gas turbine into the Brayton cycle with regenerative heating, using turbine extraction at intermediate pressure, is presented. The main concept of the retrofitting is based on the transfer of heat from the turbine exhaust gases to the air entering the combustion chamber. The extracted gas transfers heat to air via the divided regenerative heat exchanger and after that is compressed and mixed with additional air. The efficiency gain is dependent on the extraction intermediate pressure and the extraction mass flow rate. The mathematical model of the proposed cycle and its implementation in an in-house code termed COM-GAS is presented. This zero-dimensional robust model allows the prediction of basic parameters such as temperatures, combustion composition, efficiency, and other related factors. Numerical simulations of both basic models with either semi-perfect or real gases based on thermodynamic tables were compared with available exploited data, and differences between this study and others did not exceed 5%. Contrarily, differences between gas turbine cycle with regenerative heating are visible between the two models. In particular, when using the coupled classical regeneration with regeneration according to Szewalski's idea, the integrated cycle efficiency could be significantly increased up to 39.5%.

  • An Enhanced Reduced Basis Method for Wideband Finite Element Method Simulations
    • Damian Szypulski
    • Grzegorz Fotyga
    • Michał Mrozowski
    2019 Pełny tekst IEEE Access

    In this paper, we present a novel strategy for selecting expansion points in the reduced basis method. A single computation of the error estimator is used to select a few expansion points in the multi-parameter space simultaneously. The number of selected points is determined adaptively, based on the accuracy of the current reduced model. The reliability and efficiency of this proposed approach are illustrated by numerical tests considering real-life structures, including dielectric resonator filter, H-plane filter, and four-pole dielectric-loaded cavity filter.

  • An Improved Convolutional Neural Network for Steganalysis in the Scenario of Reuse of the Stego-Key
    • Bartosz Czaplewski
    2019

    The topic of this paper is the use of deep learning techniques, more specifically convolutional neural networks, for steganalysis of digital images. The steganalysis scenario of the repeated use of the stego-key is considered. Firstly, a study of the influence of the depth and width of the convolution layers on the effectiveness of classification was conducted. Next, a study on the influence of depth and width of fully connected layers on the effectiveness of classification was conducted. Based on the conclusions from the studies, an improved convolutional neural network was created, which is characterized by the state-of-art level of classification efficiency but containing 20 times less parameters to learn during the training process. Smaller number of learnable parameters results in faster network learning, easier convergence, and smaller memory and computing power requirements. The paper contains description of the current state of art, description of the experimental environment, structures of the studied networks and the results of classification accuracy.

  • An improved method for flow boiling heat transfer with account of the reduced pressure effect
    • Blanka Jakubowska
    • Dariusz Mikielewicz
    2019 Pełny tekst Thermal Science

    In the paper are presented the results 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 to investigate the sensitivity of the in-house developed model. In the work are presented the results of calculations obtained using the semi-empirical model on selected experimental flow boiling data of the refrigerants: R134a, R1234yf, R600a, R290, NH3, CO2, R236fa, R245fa, R152a, and HFE7000. In the present study, particular attention was focused on the influence of reduced pressure on the predictions of the theoretical model. The main purpose of this paper is to show the effect of the reduced pressure on the predictions of heat transfer during flow boiling.

  • An Improvement of Global Complex Roots and Poles Finding Algorithm for Propagation and Radiation Problems
    • Maciej Jasiński
    • Sebastian Dziedziewicz
    • Maria Jóźwicka
    • Piotr Kowalczyk
    2019 Pełny tekst

    An improvement of the recently developed global roots finding algorithm has been proposed. The modification allows to shorten the computational time by reducing the number of function calls. Moreover, both versions of the algorithms (standard and modified) have been tested for numerically defined functions obtained from spectral domain approach and field matching method. The tests have been performed for three simple microwave structures (open waveguides and conformal antenna resonator). The results have been verified and the increase of efficiency for the improved version of the algorithm has been confirmed.

  • An Influence of Factors of Flow Condition, Particle and Material Properties on Slurry Erosion Resistance
    • Marta Buszko
    • Alicja Krella
    2019 Pełny tekst Advances in Materials Science

    The degradation of materials due to slurry erosion is the serious problem which occurs in the power industries. The paper presents actual knowledge about an influence of individual factors connected with flow conditions, particles and material properties on the slurry erosion resistance. Among the factors connected with operating conditions, an influence of impact angle, and velocity of impact, particle concertation and liquid temperature have been described. In case of the factors connected with solid particle properties, an influence of the size, shape and hardness have been discussed. In the part devoted to the impact of material properties, due to different types of materials, the issues of resistance to erosion of slurries related to the properties of steel, ceramics and polymers are discussed separately. In the paper has been shown that a change of any of mentioned factors causes a change in the erosion rate due to the synergistic effects that accompany to slurry degradation.

  • An Optimal Power Point Tracking Algorithm in a Solar PV Generation System
    • Reyaz Hussan
    • Manita Kumari
    • Sarwar Adil
    • Atif Iqbal
    • Tariq Mohd
    • Jarosław Guziński
    2019 Pełny tekst Acta Energetica

    The non-linearity in I-V characteristics of a PV panel requires to be operated at knee point to extract maximum power. In order to operate the panel at optimal point, maximum power point tracking (MPPT) algorithm is employed in the control structure. The main objective of MPP tracking is to keep the operation at knee point of I-V characteristics under varying condition of temperature and solar insolation. Under non uniform solar PV insolation falling on PV panels connected in series, a partial shading condition (PSC) occurs under cloud or shadow effects causes multiple power peak formation. The conventional MPPT methods fail to converge at global maximum power point (GMPP) under the PSC condition. Occurrence of these multiple peaks on characteristics of P-V makes tracking very difficult and requires integration of an efficient algorithm that differentiates between global and local maximum power point. This paper proposes a variable structure constant voltage method to overcome the problem faced by conventional MPPT methods. Moreover, quadratic boost converter has been taken for MPPT operation for increasing the effective gain of the converter. The effective operation of control algorithm has been validated in simulation results.

  • An unusual four-nuclear Pb(II)-pyrrole-2-carboxylato polymer: The effect of the lone pair and non-covalent interactions on the supramolecular assembly and fluorescence properties
    • Mateusz Kowalik
    • Joanna Masternak
    • Katarzyna Kazimierczuk
    • Oleksiy Khavryuchenko
    • Bogumiła Kupcewicz
    • Barbara Barszcz
    2019 JOURNAL OF SOLID STATE CHEMISTRY

    The reaction of Pb(NO3)2 with 1H-pyrrole-2-carboxylic acid (2prCOOH) leads to the formation of a new four-nuclear Pb(II) polymer, [Pb4(2prCOO)8(H2O)]n, which has been characterized by CHN, FT-IR, TG, PL and single-crystal X-ray diffraction methods. In view of the primary Pb–O bonds, Pb1 and Pb3 show hemidirected pentagonal pyramidal geometries, while Pb2 and Pb4 display hemidirected octahedral geometries. The topology of the strongest Pb–O bonds is determined as the (4·82) fes topology. Taking the secondary Pb–O bonds into account, the coordination number of Pb centres increased, Pb1 exhibited a hemidirected monocapped pentagonal pyramidal geometry, Pb2 and Pb4 exhibited a holodirected tricapped trigonal prismatic geometry, and Pb3 exhibited a holodirected bicapped trigonal prismatic geometry. Moreover, the Pb(II) lone pair stereoactivity was confirmed by DFT calculations. The 2D structure was expanded into 3D by the existence of non-covalent O/C–H···π and Pb···π interactions, which was confirmed by the Hirshfeld surface analysis. The above mentioned interactions improve the rigidity of the structure and facilitate the charge and energy transfer between metal centres, making the polymer a promising luminescent compound.

  • Analiza danych osobowych przetwarzanych w systemach telekomunikacyjnych klasy IP PBX oraz metod ich anonimizacji za pomocą systemów SBC
    • Aleksandra Jereczek
    • Sylwester Kaczmarek
    • Marek Gorajdowski
    • Bogdan Hawrylik
    2019 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Opisano wyniki realizacji pracy, dotyczącej analizy systemu telekomunikacyjnego, opartego na technologii VoIP, pod względem wymagań prawnych powstałych wraz z wejściem w życie przepisów Ogólnego Rozporządzenia o Ochronie Danych Osobowych (RODO). Przedstawiono wyniki analizy przykładowego systemu IP PBX Asterisk oraz wykorzystywanego w nim protokołu sygnalizacyjnego SIP, w kontekście przetwarzania danych osobowych, a także metody ich ochrony przez implementację usług prywatności na urządzeniu SBC, kontrolującym sesje komunikacyjne w sieciach opartych na protokole internetowym IP.

  • Analiza efektywności systemów oświetlania roślin na przykładzie uprawy bazylii
    • Mateusz Feldzensztajn
    • Adam Mazikowski
    • Tomasz Cegielski
    2019 Pełny tekst Przegląd Elektrotechniczny

    Dynamiczny rozwój technologii LED oraz znaczące podwyżki cen energii elektrycznej wymuszają badania mające na celu zwiększenie efektywności systemów oświetleniowych do uprawy roślin. W pracy przeprowadzono analizę efektywności oświetlenia na przykładzie uprawy bazylii. Na wstępie dokonano pomiarów spektralnych liści bazylii. Na podstawie otrzymanych wyników opracowano i wykonano oświetlenie dopasowane do charakterystyki spektralnej badanej rośliny. Skuteczność zaproponowanego rozwiązania przetestowano doświadczalnie metodą porównawczą w oparciu o niewielką plantację bazylii. Część roślin oświetlana była promieniami słonecznymi, a pozostałe oświetleniem optymalizowanym. Dodatkowo wszystkim próbkom zostały zapewnione dokładnie takie same warunki rozwoju. Na podstawie otrzymanych wyników i obserwacji dokonano oceny efektywności zaproponowanego systemu oświetlenia roślin.

  • ANALIZA I OCENA WADLIWOŚCI ŁOŻYSK W ASPEKCIE II ZASADY TERMODYNAMIKI
    • Piotr Bzura
    2019 Pełny tekst Journal of Polish CIMEEAC

    W artykule przedstawiono autorską metodę sprawdzania wadliwości łożysk tocznych i ślizgowych podpierających wał napędzany trójfazowym silnikiem elektrycznym. Badania zostały przeprowadzone w aspekcie II zasady termodynamiki na podstawie analizy i oceny wyników badań laboratoryjnych wykonanych na stanowisku badawczym. Badania te wymagały zbudowania stanowiska umożliwiającego porównanie działania łożysk tocznych i ślizgowych przedmiotowegoukładu napędowego. Został przedstawiony algorytm, według którego wykonano badania empiryczne. Wykazano, że uzyskane wyniki badań potwierdziły przydatność zaproponowanej w tym artykule metody określania wartości wadliwościłożysk.Sformułowano także, w oparciu o analizę uzyskanych wyników, hipotezę badawczą, z której wynika, że zmiana podparć wału pośredniego, ze względu na rodzaj i liczbę łożysk, wpływa nadziałania wału. Hipoteza ta została zweryfikowana na podstawie testu Anova z uwzględnieniem statystyki Fishera LSD

  • ANALIZA JAKOŚCI WÓD PODZIEMNYCH W REJONIE SKŁADOWISKA ODPADÓW W GNIEWINIE NA POTRZEBY PLANOWANEJ REKULTYWACJI
    • Dawid Potrykus
    • Karolina Piskorek
    • Dariusz Rohde
    2019 Pełny tekst Biuletyn Państwowego Instytutu Geologicznego

    Składowiska odpadów stanowią jedno z potencjalnych ognisk zanieczyszczeń wód podziemnych. W celu uniknięcia za - nieczyszczenia wód podziemnych w dnie składowiska odpadów w Gniewinie został ułożony drenaż zbierający przesączające się przez odpady odcieki i odprowadzający je grawitacyjnie do zbiornika retencyjnego. Celem badań było określenie jakości wód podziemnych w rejonie składowiska odpadów w Gniewinie oraz analiza stopnia ich zanieczyszczenia pod kątem zróżnicowania przestrzennego i czaso - wego. Autorzy przeanalizowali wyniki badań wód podziemnych pochodzące z monitoringu składowiska odpadów w Gniewinie, a także porównali stężenia wybranych wskaźników między okresem powstawania sieci monitoringu z aktualnymi wynikami. Analiza wykazała zmienność składu chemicznego wód podziemnych zarówno między poszczególnymi otworami obserwacyjnymi, jak również w czasie.