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Politechniki Gdańskiej

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  • A Universal Theory of Wisdom . A Mind - oriented Approach
    • Henryk Krawczyk
    • Andrew Targowski
    2020 DIALOGUE AND UNIVERSALISM

    The purpose of the paper is to synthesize the issues of human wisdom in terms of minds which create knowledge-based judgment. We form a transdisciplinary, big-picture view of the wisdom of humans. Findings: Wisdom is the right judgment and choice in the context of the art of living. Practical implications: Wisdom can be developed within the set of minds. Social implications: To pursue wisdom in thinking and action, one must extend education to embrace more knowledge and practicing gaining better skills in decision-making. Originality: This approach offers a new understanding of the wisdom of humans, which cannot be identified as a synonym of knowledge.

  • A vector-enzymatic DNA fragment amplification-expression technology for construction of artificial, concatemeric DNA, RNA and proteins for novel biomaterials, biomedical and industrial applications
    • Piotr Skowron
    • Natalia Krawczun
    • Joanna Żebrowska
    • Daria Krefft
    • Olga Żołnierkiewicz
    • Marta Bielawa
    • Joanna Jeżewska-Frąckowiak
    • Łukasz Janus
    • Małgorzata Witkowska
    • Małgorzata Palczewska
    • Adriana Schumacher
    • Anna Wardowska
    • Milena Deptuła
    • Artur Czupryn
    • Piotr Mucha
    • Arkadiusz Piotrowski
    • Paweł Sachadyn
    • Sylwia Rodziewicz-Motowidło
    • Michal Pikuła
    • Agnieszka Zylicz-Stachula
    2020 Materials Science & Engineering C-Materials for Biological Applications

    A DNA fragment amplification/expression technology for the production of new generation biomaterials for scientific, industrial and biomedical applications is described. The technology enables the formation of artificial Open Reading Frames (ORFs) encoding concatemeric RNAs and proteins. It recruits the Type IIS SapI restriction endonuclease (REase) for an assembling of DNA fragments in an ordered head-to-tail-orientation. The technology employs a vector-enzymatic system, dedicated to the expression of newly formed, concatemeric ORFs from strong promoters. Four vector series were constructed to suit specialised needs. As a proof of concept, a model amplification of a 7-amino acid (aa) epitope from the S protein of HBV virus was performed, resulting in 500 copies of the epitope-coding DNA segment, consecutively linked and expressed in Escherichia coli (E. coli). Furthermore, a peptide with potential pro-regenerative properties (derived from an angiopoietin-related growth factor) was designed. Its aa sequence was back-translated, codon usage optimized and synthesized as a continuous ORF 10-mer. The 10-mer was cloned into the amplification vector, enabling the N-terminal fusion and multiplication of the encoded protein with MalE signal sequence. The obtained genes were expressed, and the proteins were purified. Conclusively, we show that the proteins are neither cytotoxic nor immunogenic and they have a very low allergic potential.

  • A Wind Energy Conversion System Based on a Generator with Modulated Magnetic Flux
    • Michał Gwóźdź
    • Michał Krystkowiak
    • Łukasz Ciepliński
    • Ryszard Strzelecki
    2020 Pełny tekst ENERGIES

    In this work, the concept of an energy conversion system for wind turbines based on the modified permanent magnet synchronous generator (PMSG) is presented. In the generator, a pair of three-phase windings is used, one of which is connected in a “star” and the second in a “delta” configuration. At the outputs of both windings, two six-pulse uncontrolled (diode) rectifiers are included. These rectifiers are mutually coupled by a specially designed pulse transformer, whose primary winding is powered by the power electronics converter—the so-called “current modulator”—which, in this case, operates as a magnetic flux modulator, in the generator. The modulator provides a quasi-sinusoidal magnetomotive force (mmf) in the stator of the machine. The whole system is connected to the power grid via a dedicated voltage source inverter (VSI) converter. The main objective of the elaborated solution is to provide high efficiency conversion of mechanical (wind) energy into electricity by means of a relatively simple electrical system.

  • Abdominal Aortic Aneurysm segmentation from contrast-enhanced computed tomography angiography using deep convolutional networks
    • Tomasz Dziubich
    • Paweł Białas
    • Łukasz Znaniecki
    • Joanna Halman
    • Jakub Brzeziński
    2020

    One of the most common imaging methods for diagnosing an abdominal aortic aneurysm, and an endoleak detection is computed tomography angiography. In this paper, we address the problem of aorta and thrombus semantic segmentation, what is a mandatory step to estimate aortic aneurysm diameter. Three end-to-end convolutional neural networks were trained and evaluated. Finally, we proposed an ensemble of deep neural networks with underlying U-Net, ResNet, and VBNet frameworks. Our results show that we are able to outperform state-of-the-art methods by 3% on the Dice metric without any additional post-processing steps.

  • Absolute Photoabsorption Cross-Sections of Methanol for Terrestrial and Astrophysical Relevance
    • Emanuele Lange
    • Ana Lozano
    • Nykola C. Jones
    • Søren Hoffmann
    • Sarvesh Kumar
    • Małgorzata Śmiałek-Telega
    • Denis Duflot
    • Michael J. Brunger
    • Paulo Limão-Vieira
    2020 Pełny tekst JOURNAL OF PHYSICAL CHEMISTRY A

    We investigate the methanol absorption spectrum in the range 5.5–10.8 eV to provide accurate and absolute cross-sections values. The main goal of this study is to provide a comprehensive analysis of methanol electronic-state spectroscopy by employing high-resolution vacuum ultraviolet (VUV) photoabsorption measurements together with state-of-the-art quantum chemical calculation methods. The VUV spectrum reveals several new features that are not previously reported in literature, for n > 3 in the transitions (nsσ(a′) ← (2a″)) (1A′ ← X̃1A′) and (nsσ, npσ, npσ′, ndσ ← (7a′)) (1A′ ← X̃1A′), and with particular relevance to vibrational progressions of the CH3 rocking mode, v11′(a″), mode in the (3pπ(a″) ← (2a″)) (21A′ ← X̃1A′) absorption band at 8.318 eV. The measured absolute photoabsorption cross-sections have subsequently been used to calculate the photolysis lifetime of methanol in the Earth’s atmosphere from the ground level up to the limit of the stratosphere (50 km altitude). This shows that solar photolysis plays a negligible role in the removal of methanol from the lower atmosphere compared with competing sink mechanisms. Torsional potential energy scans, as a function of the internal rotation angle for the ground and first Rydberg states, have also been calculated as part of this investigation.

  • Absolwent Wydziału Mechanicznego Złotym Inżynierem "Przeglądu Technicznego"
    • Adam Barylski
    2020 Pismo PG

    Przedstawiono sylwetke i dorobek mgr. inż. Janusza Ochocińskiego, tegorocznego laureata plebiscytu czasopima "Przegląd Techniczny", o tytuł Złotego Inżyniera 2019 w kategorii Menedżer. Pan Janusz Ochociński jest absolwentem Wydziału Mechanicznego Technologicznego Politechniki Gdańskiej z roku 1981.

  • Absorptive Desulfurization of Model Biogas Stream Using Choline Chloride-Based Deep Eutectic Solvents
    • Edyta Słupek
    • Patrycja Makoś
    2020 Pełny tekst Sustainability

    The paper presents a synthesis of deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor and phenol (Ph), glycol ethylene (EG), and levulinic acid (Lev) as hydrogen bond donors in 1:2 molar ratio. DESs were successfully used as absorption solvents for removal of dimethyl disulfide (DMDS) from model biogas steam. Several parameters affecting the absorption capacity and absorption rate have been optimized including kinds of DES, temperature, the volume of absorbent, model biogas flow rate, and initial concentration of DMDS. Furthermore, reusability and regeneration of DESs by means of adsorption and nitrogen barbotage followed by the mechanism of absorptive desulfurization by means of density functional theory (DFT) as well as FT-IR analysis were investigated. Experimental results indicate that the most promising DES for biogas purification is ChCl:Ph, due to high absorption capacity, relatively long absorption rate, and easy regeneration. The research on the absorption mechanism revealed that van der Waal interaction is the main driving force for DMDS removal from model biogas

  • Accelerated design optimization of miniaturized microwave passives by design reusing and Kriging interpolation surrogates
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 Pełny tekst AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS

    Electromagnetic (EM) analysis has become ubiquitous in the design of microwave components and systems. One of the reasons is the increasing topological complexity of the circuits. Their reliable evaluation—at least at the design closure stage—can no longer be carried out using analytical or equivalent network representations. This is especially pertinent to miniaturized structures, where considerable EM cross-coupling effects occurring in densely arranged layouts affect the performance in a non-negligible manner. Although mandatory, EM-driven design is normally associated with significant computational expenses. Consequently, expediting the procedures that require massive simulations, such as parametric optimization, is a practical necessity. In this paper, a framework for accelerated parameter tuning is proposed. The keystones of our methodology are a set of pre-existing designs optimized for various design objectives, as well as kriging interpolation surrogates. The latter are constructed to yield—for a given set of performance specifications—a reasonably good starting point and to enable rapid optimization by providing the initial approximation of the Jacobian matrix of the circuit outputs. The proposed approach is validated using two compact impedance matching transformers designed within the objective spaces defined by wide ranges of operating bandwidths. As demonstrated, the average tuning cost corresponds to a few EM simulations of the respective circuit despite large numbers of adjustable parameters.

  • Accelerated multi-objective design of miniaturized microwave components by means of nested kriging surrogates
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2020 Pełny tekst INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING

    Design of microwave components is an inherently multiobjective task. Often, the objectives are at least partially conflicting and the designer has to work out a suitable compromise. In practice, generating the best possible trade‐off designs requires multiobjective optimization, which is a computationally demanding task. If the structure of interest is evaluated through full‐wave electromagnetic (EM) analysis, the employment of widely used population‐based metaheuristics algorithms may become prohibitive in computational terms. This is a common situation for miniaturized components, where considerable cross‐coupling effects make traditional representations (eg, network equivalents) grossly inaccurate. This article presents a framework for accelerated EM‐driven multiobjective design of compact microwave devices. It adopts a recently reported nested kriging methodology to identify the parameter space region containing the Pareto front and to render a fast surrogate, subsequently used to find the first approximation of the Pareto set. The final trade‐off designs are produced in a separate, surrogate‐assisted refinement process. Our approach is demonstrated using a three‐section impedance matching transformer designed for the best matching and the minimum footprint area. The Pareto set is generated at the cost of only a few hundred of high‐fidelity EM simulations of the transformer circuit despite a large number of geometry parameters involved.

  • Accelerated Re-Design of Antenna Structures Using Sensitivity-Based Inverse Surrogates
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    2020 Pełny tekst IEEE Access

    The paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant reduction of the number of reference designs required to render the surrogate. Rigorous formulation of the approach is supplemented by its comprehensive numerical validation using a triple-band uniplanar dipole antenna and a dual-band monopole antenna re-designed with respect to operating frequencies as well as the substrate parameters (thickness and dielectric permittivity). It is demonstrated that—for the considered test cases—the reliable inverse model can be set up using a significantly smaller (by a factor of three) number of reference points as compared to the original version of the method, whereas the dimension scaling process itself requires up to four EM simulations of the antenna structure.

  • Accuracy of Trajectory Tracking Based on Nonlinear Guidance Logic for Hydrographic Unmanned Surface Vessels
    • Andrzej Stateczny
    • Paweł Burdziakowski
    • Klaudia Najdecka
    • Beata Domagalska-Stateczna
    2020 Pełny tekst SENSORS

    A new trend in recent years for hydrographic measurement in water bodies is the use of unmanned surface vehicles (USVs). In the process of navigation by USVs, it is particularly important to control position precisely on the measuring profile. Precise navigation with respect to the measuring profile avoids registration of redundant data and thus saves time and survey costs. This article addresses the issue of precise navigation of the hydrographic unit on the measuring profile with the use of a nonlinear adaptive autopilot. The results of experiments concerning hydrographic measurements performed in real conditions using an USV are discussed.

  • Accurate Computation of IGBT Junction Temperature in PLECS
    • Paweł Górecki
    • Daniel Wojciechowski
    2020 IEEE TRANSACTIONS ON ELECTRON DEVICES

    In the article, a new method to improve the accuracy of the insulated-gate bipolar transistor (IGBT) junction temperature computations in the piecewise linear electrical circuit simulation (PLECS) software is proposed and described in detail. This method allows computing the IGBT junction temperature using a nonlinear compact thermal model of this device in PLECS. In the method, a nonlinear compact thermal model of the IGBT is used, which considers the dependence of thermal resistance on the junction temperature. The usefulness of the method is experimentally verified, and it is confirmed that it increases the accuracy of the computations and shortens their time. The differences between the measured and computed characteristics are discussed. The application of the developed method for computations resulted in a significant reduction of their error to only a few percent. The developed method can be applied in the system-level simulations of the power electronics converters.

  • ‘Acridines’ as New Horizons in Antifungal Treatment
    • Iwona Gabriel
    2020 Pełny tekst MOLECULES

    Frequent fungal infections in immunocompromised patients and mortality due to invasive mycosis are important clinical problems. Opportunistic pathogenic Candida species remain one of the leading causes of systemic mycosis worldwide. The repertoire of antifungal chemotherapeutic agents is very limited. Although new antifungal drugs such as lanosterol 14α-demethylase and β-glucan synthase inhibitors have been introduced into clinical practice, the development of multidrug resistance has become increasingly significant. The urgency to expand the range of therapeutic options for the treatment of fungal infections has led researchers in recent decades to seek alternative antifungal targets to the conventional ones currently used. Among them, many compounds containing an acridine scaffold have been synthesized and tested. In this review, the applicability of acridines and their functional analogues acridones as antifungal agents is described. Acridine derivatives usage in photoantifungal chemotherapy, interactions with fungal transporters resulting in modulation of efflux/influx pumps and the effect of acridine derivatives on fungal topoisomerases are discussed. This article explores new perspectives on the mechanisms of antifungal acridine-peptide conjugates and acridine-based hybrid molecules to effectively combat fungal infections.

  • Activated Carbon Produced by Pyrolysis of Waste Wood and Straw for PotentialWastewater Adsorption
    • Katarzyna Januszewicz
    • Paweł Kazimierski
    • Maciej Klein
    • Dariusz Kardaś
    • Justyna Łuczak
    2020 Pełny tekst Materials

    Pyrolysis of straw pellets and wood strips was performed in a fixed bed reactor. The chars, solid products of thermal degradation, were used as potential materials for activated carbon production. Chemical and physical activation processes were used to compare properties of the products. The chemical activation agent KOH was chosen and the physical activation was conducted with steam and carbon dioxide as oxidising gases. The eect of the activation process on the surface area, pore volume, structure and composition of the biochar was examined. The samples with the highest surface area (1349.6 and 1194.4 m2/g for straw and wood activated carbons, respectively) were obtained when the chemical activation with KOH solution was applied. The sample with the highest surface area was used as an adsorbent for model wastewater contamination removal.

  • Activation of N2O and SO2 by the P–B Bond System. Reversible Binding of SO2 by the P–O–B Geminal Frustrated Lewis Pair
    • Natalia Szynkiewicz
    • Jarosław Chojnacki
    • Rafał Grubba
    2020 Pełny tekst INORGANIC CHEMISTRY

    Herein, we present the first transformation of borylphosphine into borylphosphinite using nitrous oxide. Borylphosphine reacts with N2O via insertion of a single oxygen atom into the P−B bond and formation of a P−O−B bond system. Borylphosphine and borylphosphinite capture SO2 and activate it in an irreversible and reversible manner, respectively.

  • Activation of peroxymonosulfate using carbon black nano-spheres/calcium alginate hydrogel matrix for degradation of acetaminophen: Fe3O4 co-immobilization and microbial community response
    • Reza Darvishi Cheshmeh Soltani
    • Mansoureh Mahmoudi
    • Grzegorz Boczkaj
    • Alireza Khataee
    2020 Pełny tekst JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY

    Herein, we focused on the degradation of acetaminophen (ACT) drug in liquid phase by peroxymonosulfate (PMS) activated by carbon black nano-spheres (CBNS). The nanostructured activator was immobilized into calcium alginate hydrogel matrix (CAHM) to avoid the washout of the fine nanostructures. The Langmuir modeling showed an insignificant contribution to the adsorption process in the removal of ACT. The basic pH conditions favored the decomposition of ACT. Among nutrients, the presence of nitrogenous compounds including nitrite, nitrate and ammonium caused a little decrease in the reactor performance, while the addition of phosphate ion improved the efficiency from 76.8 to 81.9%. The results demonstrated the involvement of both SO4•− and •OH radicals in the degradation of ACT and domination of SO4•− radicals in the degradation process. Co-immobilization of the CBNS with electro-synthesized magnetite nanoparticles resulted in not only the enhanced reusability potential but also improved the efficiency of the treatment process to 95.6%. Mineralization efficiency of the process was not remarkable; however, the process produced an effluent with lower toxicity toward the microbial community of the activated sludge.

  • Adapting Agile Practices to Security Context – Practitioners’ Perspective
    • Katarzyna Łukasiewicz
    • Sara Cygańska
    2020

    In this paper we explore the problem of introducing agile practices to projects dealing with systems with high security requirements. We also propose an approach based on AgileSafe method and OWASP ASVS guidelines, that could support such introduction. What is more, we present the results of two surveys aimed at analyzing IT practitioners’ views on applying agile methods to security reliant systems as well as evaluating the set of agile security-oriented practices which are a part of the proposed approach. This paper is an extended version of the paper “Security-oriented agile approach with AgileSafe and OWASP ASVS” that was published as a part of LASD 2019 conference proceedings

  • Adaptive Algorithm of a Tap-Changer Controller of the Power Transformer Supplying the Radial Network Reducing the Risk of Voltage Collapse
    • Robert Małkowski
    • Michał Izdebski
    • Piotr Miller
    2020 Pełny tekst ENERGIES

    he development of renewable energy, including wind farms, photovoltaic farms as well as prosumer installations, and the development of electromobility pose new challenges for network operators. The results of these changes are, among others, the change of network load profiles and load flows determining greater volatility of voltages. Most of the proposed solutions do not assume a change of the transformer regulator algorithm. The possibilities of improving the quality of regulation, which can be found in the literature, most often include various methods of coordination of the operation of the transformer regulator with various devices operating in the Medium-Voltage (MV) network. This coordination can be decentralized or centralized. Unfortunately, the proposed solutions often require costly technical resources and/or large amounts of real-time data monitoring. The goal of the authors was to create an algorithm that extends the functionality of typical transformer control algorithms. The proposed solution allows for reducing the risk of voltage collapse. The performance of the proposed algorithm was validated using multivariate computer simulations and tests with the use of a physical model of the distribution network. The DIgSILENT PowerFactory environment was used to develop the simulation model of the proposed algorithm. Then, tests were conducted on real devices installed in the LINTEˆ2 Laboratory at the Gdańsk University of Technology, Poland. Selected test results are included in this paper. All results have shown that the proposed algorithm makes it possible to increase the reserve of the voltage stability of the node, in which it is applied, thus mitigating the risk of a voltage collapse occurring. The proposed algorithm does not require complex and costly technical solutions. Owing to its simplicity, it has a high potential for practical application, as confirmed by the real-time control experiment in the laboratory.

  • Adaptive Positioning Systems Based on Multiple Wireless Interfaces for Industrial IoT in Harsh Manufacturing Environments
    • Jordi Mongay Batalla
    • Constandinos X. Mavromoustakis
    • George Mastorakis
    • Neal Xiong, Naixue
    • Józef Woźniak
    2020 Pełny tekst IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS

    As the industrial sector is becoming ever more flexible in order to improve productivity, legacy interfaces for industrial applications must evolve to enhance efficiency and must adapt to achieve higher elasticity and reliability in harsh manufacturing environments. The localization of machines, sensors and workers inside the industrial premises is one of such interfaces used by many applications. Current localization-based systems are unable to deal with highly variable conditions, meaning that the solutions working well in stationary systems suffer from considerable difficulties in harsh environments, such as factories. As a result, the precision of localization techniques is not satisfactory in most industrial applications. This paper fills in the existing gap between static approaches and dynamic indoor positioning systems, by presenting a solution adapting the system to highly changeable conditions. The proposed solution makes use of a Machine Learning-based feedback loop that learns the variability of the environment. This feedback makes continuous fingerprint calibration feasible even in the presence of different machines and Industrial Internet of Things sensors that introduce variations to the electromagnetic environment. This paper also presents a comprehensive indoor positioning system solution that reduces complexity of hardware, meaning that a multi-standard-transceiver infrastructure may be adopted with reduced capital and operational expenditures.We have developed the system from scratch and have conducted an extensive range of testbed experiments showing that the multi-technology transceiver feature is capable of increasing positioning accuracy, as well as of introducing permanent fingerprints calibration at harsh industrial premises.

  • Adaptive traffic optimization using Variable Speed Limits; Adaptacyjna optymalizacja ruchu drogowego przy pomocy zmiennych ograniczeń prędkości
    • Paweł Gora
    2020

    Variable speed limits (VSL) is an intelligent transportation system (ITS) solution for traffic management. The speed limits can be changed dynamically in order to adapt to traffic, weather, or road surface conditions. This paper presents an approach for such an adaptive traffic control where the primary goal is to ensure traffic safety and efficiency of the traffic control system (fast response to dynamically changing traffic, weather and road surface conditions). In the case of the straight roads, the method takes into account road surface conditions, visibility, and traffic density. In the case of bends, it takes into account the curvature and the road adhesion but also tries to harmonize speed before and after the bend. The experiments on a selected road segment conducted using a simulation framework SUMO with various traffic flows and weather conditions showed that the method works fine and is able to reduce the speed of cars to safe values depending on the road surface conditions, visibility, and traffic.

  • Adsorption behavior and corrosion inhibitive characteristics of newly synthesized cyano-benzylidene xanthenes on copper/sodium hydroxide interface: Electrochemical, X-ray photoelectron spectroscopy and theoretical studies
    • Mohamed Khalifa
    • Islam Azab El
    • Adil Gobouri
    • Gaber Mersal
    • Sarah Alharthi
    • Murat Saracoglu
    • Fatma Kandemirli
    • Jacek Ryl
    • Mohammed Amin
    2020 Pełny tekst JOURNAL OF COLLOID AND INTERFACE SCIENCE

    Elegant process for synthesis of 3-(7H-dibenzo[c,h]xanthen-7-yl)benzaldehyde (3), as new starting material to create a set of novel xanthene analogues, 2-(3-(7H-dibenzo[c,h]xanthen-7-yl)benzylidene)malononitrile (4), 3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylic acid (5), and Ethyl-3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylate (6), was achieved starting with available materials under mild conditions. Various concentrations (ca. 0.1–1.0 mM) of the synthesized cyano-benzylidene xanthene derivatives, namely compounds 3–6, were tested as inhibitors to control copper corrosion in alkaline solutions employing polarization and electrochemical impedance spectroscopy (EIS) measurements. Results revealed that the four studied xanthenes derivatives served as efficient (mixed-type) inhibitors. The inhibition efficiency increased with increase in inhibitor concentration.The inhibition performance of studied compounds varied according to their chemical structures. The best inhibitor, compound (5), achieved a maximum inhibition efficiency of 98.7% (calculated from corrosion current densities) and ~ 95% (estimated from charge-transfer resistance values) at a concentration of 1.0 mM. The morphology of the corroded and inhibited copper surfaces was studied by scanning electron microscopy (SEM). The adsorption of the inhibitor molecules was confirmed by high-resolution X-ray photoelectron spectroscopy (XPS) profiles. XPS data were used to compare the inhibition efficiencies exhibited by studied compounds. The oxidation rate of the Cu surface was found to be frivolous, referring to high inhibition efficiency, only in the presence of inhibitor (5), and Cu0 share is 87% of all copper components. The shares of Cu0 were significantly reduced to 43%, 26% and 20% for inhibitors (3), (4) and (6), respectively. These findings go parallel with the results obtained from electrochemical measurements. The quantum-chemical calculations of the investigated molecules were performed to support electrochemical findings, and their correlations with the inhibition efficiency of the synthesized compounds were discussed.

  • Advanced Lithium-Ion Battery Model for Power System Performance Analysis
    • Szymon Potrykus
    • Filip Kutt
    • Janusz Nieznański
    • Francisco Jesús Fernández Morales
    2020 Pełny tekst ENERGIES

    The paper describes a novel approach in battery storage system modelling. Different types of lithium-ion batteries exhibit differences in performance due to the battery anode and cathode materials being the determining factors in the storage system performance. Because of this, the influence of model parameters on the model accuracy can be different for different battery types. These models are used in battery management system development for increasing the accuracy of SoC and SoH estimation. The model proposed in this work is based on Tremblay model of the lithium-ion battery. The novelty of the model lies in the approach used for parameter estimation as a function of battery physical properties. To make the model perform more accurately, the diffusion resistance dependency on the battery current and the Peukert effect were also included in the model. The proposed battery model was validated using laboratory measurements with a LG JP 1.5 lithium-ion battery. Additionally, the proposed model incorporates the influence of the battery charge and discharge current level on battery performance.

  • Advanced operating methods
    • Janusz Smulko
    2020

    Selected operating methods of resistive gas sensors were presented. The methods utilize flicker noise (1/f noise), which gives additional information about ambient gas when compared with the recorded changes of DC resistance only. Methods of flicker noise measurements were outlined. Recently developed prototype gas sensors comprising golden nanoparticle functionalized with organic ligands can generate intense flicker noise induced by volatile organic compounds. These phenomena can be utilized in inexpensive and portable measurement setups. Popular gas sensing materials (e.g., WO3 and TiO2) exhibit a photocatalytic effect, which can be employed to improve the selectivity and sensitivity of gas detection. Recently proposed commercial resistive gas sensors are of much smaller dimensions and energy consumption. These new series of gas sensors can be used in the proposed methods when limited energy consumption is a crucial factor. An overview of emerging new applications of low-cost resistive gas sensors is given. Bootlegs of the technology arising were identified and compared with the applications presented.

  • Advanced Turbine Cycles with Organic Media
    • Marian Piwowarski
    • Krzysztof Kosowski
    2020 Pełny tekst ENERGIES

    Organic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible to overcome these difficulties by certain modifications of the thermodynamic cycles, a proper choice of the working medium and the optimization of cycle parameters. In the paper the problems of choosing the working medium and the question of higher temperature at the turbine inlet have been discussed. Different modifications of the schemas of the thermodynamic cycles have also been taken into account. The variants of power plants with regenerators, reheaters and heat exchangers have been considered. The proposed increase in temperature (in some cases up to 600 °C or higher) and innovative modifications of the thermodynamic cycles allow to obtain the power plant efficiency of above 50%. The modified cycles have been described in detail in the paper. The proposed cycles equipped with regenerators and reheaters can have the efficiency even slightly higher than classical steam turbine plants with a reheater and regenerators. Appropriate cycle and turbine calculations have been performed for the micro power plants of turbine output in the range of 10 kW–300 kW (up to several MW in some cases). The best arrangements achieved very high values of the overall cycle efficiency.

  • Advancing the evidence base for public policies impacting on dietary behaviour, physical activity and sedentary behaviour in Europe: The Policy Evaluation Network promoting a multidisciplinary approach
    • Jeroen Lakerveld
    • Catherine Woods
    • Antje Hebestreit
    • Hermann Brenner
    • Marion Flechtner-Mors
    • Janas M. Harrington
    • Carlijn B.M. Kamphuis
    • Michael Laxy
    • Aleksandra Luszczynska
    • Mario Mazzocchi
    • Celine Murrin
    • Maartje Poelman
    • Ingrid Steenhuis
    • Gun Roos
    • Jürgen M. Steinacker
    • Christian C. Stock
    • Frank van Lenthe
    • Hajo Zeeb
    • Joanna Żukowska
    • Wolfgang Ahrens
    2020 Pełny tekst FOOD POLICY

    Non-communicable diseases (NCDs) are the leading cause of global mortality. As the social and economic costs of NCDs have escalated, action is needed to tackle important causes of many NCD’s: low physical activity levels and unhealthy dietary behaviours. As these behaviours are driven by upstream factors, successful policy interventions are required that encourage healthy dietary behaviours, improve physical activity levels and reduce sedentary behaviours of entire populations. However, to date, no systematic research on the implementation and evaluation of policy interventions related to these health behaviours has been conducted across Europe. Consequently, no information on the merit, gaps, worth or utility of cross-European policy interventions is available, and no guidance or recommendations on how to enhance this knowledge across European countries exists. As part of the Joint Programming Initiative “A Healthy Diet for a Healthy Life” (JPI HDHL), 28 research institutes from seven European countries and New Zealand have combined their expertise to form the Policy Evaluation Network (PEN). PEN’s aim is to advance tools to identify, evaluate, implement and benchmark policies designed to directly or indirectly target dietary behaviours, physical activity, and sedentary behaviour in Europe, as well as to understand how these policies increase or decrease health inequalities. Using well-defined evaluation principles and methods, PEN will examine the content, implementation and impact of policies addressing dietary behaviour, physical activity levels and sedentary behaviour across Europe. It will realise the first steps in a bespoke health policy monitoring and surveillance system for Europe, and refine our knowledge of appropriate research designs and methods for the quantification of policy impact. It will contribute to our understanding of how to achieve successful transnational policy implementation and monitoring of these policies in different cultural, demographic or socioeconomic settings. PEN will consider equity and diversity aspects to ensure that policy actions are inclusive and culturally sensitive. Finally, based on three policy cases, PEN will illustrate how best to evaluate the implementation and impact of such policies in order to yield healthy diets and activity patterns that result in healthier lives for all European citizens.

  • Advantageous conditions of saccharification of lignocellulosic biomass for biofuels generation via fermentation processes
    • Karolina Kucharska
    • Edyta Słupek
    • Hubert Cieśliński
    • Marian Kamiński
    2020 Pełny tekst CHEMICAL PAPERS

    Processing of lignocellulosic biomass includes four major unit operations: pre-treatment, hydrolysis, fermentation and product purifcation prior to biofuel generation via anaerobic digestion. The microorganisms involved in the fermentation metabolize only simple molecules, i.e., monosugars which can be obtained by carrying out the degradation of complex polymers, the main component of lignocellulosic biomass. The object of this paper was to evaluate the saccharifcation conditions and identify the process parameters that should be applied to improve the saccharifcation efciency of lignocellulosic biomass, defned as the simple sugars concentration, which was considered as a crucial parameter for hydrogen generation via dark fermentation. Drawing global conclusions about the occurring changes in the biomass requires learning about the nature of the biomass structure and composition at diferent stages of the process. Therefore, techniques for analysis, as FTIR, HPLC and SEM were applied. The experiment was planned employing Box–Behnken design. The advantageous operating conditions and the composition of saccharifcation enzymatic cocktail were identifed and their values occurred similar in the applied border conditions for all tested biomass types. Analysis of the intermediate solid and liquid streams generated during the pre-treatment procedure revealed several structural and compositional changes in the biomass.

  • AEGIS – Mobile Device for Generating Electromagnetic Curtain for Special Applications and Countering the Threats of RCIED
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Magiera
    • Alicja Olejniczak
    • Paweł Kosz
    • Agnieszka Czapiewska
    • Robert Burczyk
    • Krzysztof Kowalewski
    • Jarosław Sadowski
    • Sławomir Ambroziak
    2020 Pełny tekst International Journal of Electronics and Telecommunications

    In the article the assumptions, design and realization of the technological demonstrator of a mobile device for generating an electromagnetic curtain (with a cryptonym AEGIS) were presented, both in the area of hardware and software. The device is designed to block the radio communication systems by which it is possible to detonate the Radio Controlled Improvised Explosive Devices (RCIEDs). The preliminary laboratory tests of the demonstrator for generating the jamming signal, that were presented in the paper, aimed at assessing the correctness of the device operation and verification of generated signal parameters. On the basis of the obtained results, the ability to jam the cellular systems as well as other radio devices operating in the frequency band from 400 MHz to 2700 MHz was assessed.

  • Aerodynamic Shape Optimization for Delaying Dynamic Stall of Airfoils by Regression Kriging
    • Vishal Raul
    • Leifur Leifsson
    • Sławomir Kozieł
    2020

    The phenomenon of dynamic stall produce adverse aerodynamic loading which can adversely affect the structural strength and life of aerodynamic systems. Aerodynamic shape optimization (ASO) provides an effective approach for delaying and mitigating dynamic stall characteristics without the addition of auxiliary system. ASO, however, requires multiple evaluations time-consuming computational fluid dynamics models. Metamodel-based optimization (MBO) provides an efficient approach to alleviate the computational burden. In this study, the MBO approach is utilized for the mitigation of dynamic stall characteristics while delaying dynamic stall angle of the flow past wind turbine airfoils. The regression Kriging metamodeling technique is used to approximate the objective and constrained functions. The airfoil shape design variables are described with six PARSEC parameters. A total of 60 initial samples are used to construct the metamodel, which is further refined with 20 infill points using expected improvement. The metamodel is validated with the normalized root mean square error based on 20 test data samples. The refined metamodel is used to search for the optimal design using a multi-start gradient-based method. The results show that an optimal design with a 3∘ delay in dynamic stall angle as well a reduction in the severity of pitching moment coefficients can be obtained.

  • Agile Requirements Prioritization in Practice: Results of an Industrial Survey
    • Aleksander Jarzębowicz
    • Natalia Sitko
    2020 Pełny tekst Procedia Computer Science

    Agile software development stresses the importance of providing the customer with a product of a maximized business value. To achieve that, requirements prioritization is used. Agile development methods like Scrum define guidelines for prioritization, however practitioners do not necessarily have to follow them. Our goal was to investigate the industry practice related to requirements prioritization process, including its timing, participants, criteria used and prioritization techniques applied. We designed an on-line questionnaire (based on literature review) and conducted a survey involving practitioners from Polish IT industry. We received 69 valid responses indicating requirements prioritization practices in industrial Agile projects. We found out that despite the fact that business value is the most common criterion used to prioritize requirements, other criteria like complexity, stability and mutual interdependencies are considered as well. Other findings indicate that consideration of such multiple criteria requires different viewpoints, thus making requirements prioritization a process that has to involve many participants of different roles and competencies.

  • AGREE—Analytical GREEnness Metric Approach and Software
    • Francisco Pena-Pereira
    • Wojciech Wojnowski
    • Marek Tobiszewski
    2020 Pełny tekst ANALYTICAL CHEMISTRY

    Green analytical chemistry focuses on making analytical procedures more environmentally benign and safer to humans. The amounts and toxicity of reagents, generated waste, energy requirements, the number of procedural steps, miniaturization, and automation are just a few of the multitude of criteria considered when assessing an analytical methodology’s greenness. The use of greenness assessment criteria requires dedicated tools. We propose the Analytical GREEnness calculator, a comprehensive, flexible, and straightforward assessment approach that provides an easily interpretable and informative result. The assessment criteria are taken from the 12 principles of green analytical chemistry (SIGNIFICANCE) and are transformed into a unified 0−1 scale. The final score is calculated based on the SIGNIFICANCE principles. The result is a pictogram indicating the final score, performance of the analytical procedure in each criterion, and weights assigned by the user. Freely available software makes the assessment procedure straightforward. It is open-source and downloadable from https://mostwiedzy.pl/AGREE.

  • Air-cooled photovoltaic roof tile as an example of the BIPVT system – An experimental study on the energy and exergy performance
    • Jan Wajs
    • Aleksandra Gołąbek
    • Roksana Bochniak
    • Dariusz Mikielewicz
    2020 Pełny tekst ENERGY

    The air-cooled photovoltaic tile is a subject of presented investigations, which focused on improving the overall system efficiency of PV tiles with heat recovery. The operational efficiency of a PV roof tile, together with the construction optimising the air cooling efficiency, were the main points of plans realized at this research stage. The article describes the experimental research consisting of the assessment of electrical, thermal, and total efficiency, as well as exergy efficiency and parameters of a commercial photovoltaic (PV) roof tile, which back wall was cooled by flowing air. An influence of various cooling duct depths and various volumetric flow rates on the system operation was analysed. During the tests, a solar light simulator and a radial fan, providing the assumed volumetric flow rate of cooling air were used. It has been proven that the depth of the cooling duct and the air volumetric flow rate have a crucial impact on the obtained results. Air cooling the back wall of the PV roof tile, lowered the average surface temperature by a maximum of 6.3 K, while the temperature difference, between the surface next to the cooling air inlet and the surface next to its outlet, was a maximum of 23.4 K. Both values were obtained for air cooling with a volumetric flow rate equal to 4 m3/h and a channel depth of 25 mm, with a solar irradiance of 900 W/m2. The overall efficiency was calculated as a sum of the electrical an thermal efficiencies. Its maximal obtained value was about 32%, wherein the highest thermal efficiency was at the level of 27%. An exergy analysis was performed and the exergy efficiency between 5.08 % and 9.94 % was determined. These results are promising for future utilization of the system consisted of the PV roof tiles together with the cooling ducts.

  • Aktualność "Sporu o istnienie świata" Romana Ingardena w świetle współczesnych mu stanowisk filozoficznych
    • Andrzej Lisak
    2020 Pełny tekst Przegląd Filozoficzny Nowa Seria

    Paradoksalnie Ingarden nie jest w stanie wykazać, że świat realny istnieje w pewnym zasadniczym sensie „istnienia”, bo przyjmuje taki sam jak Husserl egologiczny, przeżyciowy model czystej świadomości i sam podążając za Husserlem przyjmuje istnienie dwóch dziedzin przedmiotów indywidualnych: dziedzinę czystej świadomości (rozumianej po husserlowsku jako strumień przeżyć) i dziedzinę świata realnego za punkt wyjścia swoich rozważań. Świadomość pojmowana jest tutaj jako zbiór aktów, a nie treści. Świadomość jest jednak(co dobrze pokazał w neokantyźmie Natorp, a w obrębie fenomenologii Sartre) pierwotnością, w której konstytuuje się z jednej strony świat a drugiej strony realny podmiot, sama więc nie może być utożsamiana z podmiotem Sama niczego nie konstytuuje, ale jest miejscem, w którym widzimy samą konstytucję Świadomość tak pojęta nie zawiera przeżycia świata, ale jest bezpośrednio przy bycie. To, że posiadamy przeżycie świata jest dopiero wtórnie przez już ukonstytuowany w pierwotnej świadomości podmiot domniemane. Dzielone wspólnie z Husserlem kartezjańskie założenia w połączeniu z przejętym z empiryzmu brytyjskiego modelem poznania: „treść wrażeniowa – jej intencjonalne ujęcie” oraz w połączeniu z tym, co określam „metafizyką ciała stałego” są powodem fiaska projektu Ingardena. Odsłaniane są zarazem te momenty filozofii Ingardena, które rzeczywiście prowadzą w stronę realizmu.

  • Aktywna Termografia Dynamiczna - przetwarzanie serii obrazów w diagnostyce medycznej
    • Mariusz Kaczmarek
    • Antoni Nowakowski
    2020

    Aktywna termografia dynamiczna (ATD) jest metodą obrazowania zmian temperatury na powierzchni badanego obiektu w czasie jako odpowiedź na zastosowane pobudzenie zewnętrzne (ogrzewanie lub chłodzenie). Celem badania jest określenie właściwości obiektu w czasie trwania termicznych procesów przejściowych, takich jak grzanie lub chłodzenie. Obiekt badany jest pobudzany sygnałem cieplnym (zewnętrznie) lub farmakologicznie (wewnętrznie). Formą odpowiedzi obiektu na to pobudzenie jest zmiana temperatury (wzrost lub spadek), a szybkość zmian temperatury zawiera informację o wartościach pojemności cieplnej (Cp) i przewodności cieplnej (ke), charakteryzujących strukturę badanego obiektu. Dla organizmów żywych należy jednak uwzględniać transport ciepła przez krew, a także procesy generacji ciepła w cyklu metabolicznym. Mechanizmy te ujęte są w modelu zaproponowanym w latach 40-tych XX wieku przez Pennesa. Jest to tzw. równanie biologicznego przepływu ciepła. Zdefiniowanych dodatkowych czynników biologicznych nie ma w przypadku analizy przejściowych procesów cieplnych w materiałach sztucznych-przemysłowych. ATD może stanowić w badaniach medycznych nową jakość, jako że pozwala na określenie właściwości termicznych tkanek będących często pochodnymi ukrwienia i procesów metabolicznych. Stanowi też uzupełnienie dla termografii statycznej, która jest bardziej podatna na działanie czynników zewnętrznych. W dotychczasowych aplikacjach aktywnej termografii dynamicznej w medycynie można wyróżnić dwa kierunki. Pierwszy, związany jest z badaniem zmian homeostazy badanej tkanki, na którą zadziałał bodziec np. w kardiochirurgii przy badaniu drożności naczyń. Drugi kierunek koncentruje się na badaniu powierzchni tkanki i różnicowaniu obszarów patologicznych od prawidłowych, które charakteryzują się odmiennymi parametrami termicznymi takimi jak przewodność cieplna i pojemność cieplna. Dla termografii z wymuszeniem rozkład temperatury będzie się zmieniał na kolejnych termogramach wraz z trwaniem bodźca termicznego, a po jego ustaniu obserwowana na powierzchni temperatura będzie dążyła do stanu równowagi termicznej, a rozkład temperatury również będzie się zmieniał, aż do osiągnięcia stanu ustalonego. Te procesy dążenia do osiągnięcia stanu ustalonego można scharakteryzować tzw. zastępczym modelem termicznym (ZMT), najczęściej pewną postacią równania matematycznego ze współczynnikami, których wartości wyznaczone zostaną w procedurze dopasowania do danych pomiarowych (PDD).

  • Aktywność biologiczna koniugatów nanonośników molekularnych z inhibitorami enzymatycznymi
    • Dorota Martynow
    2020 Pełny tekst

    Przedmiotem badań były cztery grupy koniugatów nanonośników molekularnych z inhibitorami enzymatycznymi o potencjalnym działaniu przeciwgrzybowym. Pierwszą z tych grup tworzyły koniugaty peptydów penetrujących z inhibitorem gyrazy ciprofloksacyną lub z cząsteczką kwasu N3-(4-metoksyfumaroilo)-L-2,3-diaminopropanowego (FMDP), inhibitorem syntazy GlcN-6-P. W dwóch kolejnych grupach, cząsteczki FMDP oraz cispentacyny, inhibitora syntetazy Ile-tRNAIle połączone były z nanonośnikami lipidowymi lub tzw. parasolami molekularnymi. W niektórych z tych koniugatów występował ,jako dodatkowy składnik mający zapewnić efektywne uwalnianie inhibitora, tzw. „trimethyl lock‖. Ponadto, zbadano także wpływ skoniugowania parasoli molekularnych z antybiotykami przeciwgrzybowymi z grupy makrolidów polienowych na ich selektywną toksyczność in vitro w układzie komórki grzybowe: komórki ssacze. Wykonano szereg badań dotyczących nośników związków aktywnych o działaniu przeciwgrzybowym. Wykazano, że ich modyfikacja za pomocą nośników może doprowadzić do polepszenia aktywności przeciwgrzybowej, polepszenia zdolności transportowych oraz zmniejszenia właściwości hemolitycznych i cytotoksycznych. Wykonane badania mogą służyć jako silne podstawy do zaprojektowania skutecznego i nietoksycznego układu nośnik-lek o działaniu przeciwgrzybowym.

  • AKUSTYCZNY ASPEKT ZASTOSOWANIA BLACHY KORTENOWEJ W EUROPEJSKIM CENTRUM SOLIDARNOŚCI W GDAŃSKU
    • Andrzej Kulowski
    • Wojciech Targowski
    2020

    Artykuł opisuje użycie blachy kortenowej jako dominującego materiału wykończeniowego na elewacjach i we wnętrzach budynku o przesłaniu symbolicznym. Przedstawiono architektoniczne przesłanki, uzasadniające jednorodność zastosowanego materiału. Na tym tle omówiono wpływ blachy kortenowej na akusty-kę pomieszczeń, wraz z podaniem kroków zaradczych redukujących nadmierną pogłosowość i zwiększających stopień rozproszenia dźwięku. Pozytywnym sprawdzianem dla warunków akustycznych uzyskanych w największym pomieszczeniu ECS jest zaprezentowanie w nim dużego dzieła z dziedziny muzyki klasycznej.

  • "Alians znaków"
    • Dominika Krechowicz
    2020

    Wystawa "Koncepcja obrazu - Twórcy Galerii Koło". Prezentacja nowej pracy z cyklu "Alians znaków" na wystawie w Centrum Sztuki Współczesnej Łaźnia 2, ul. Strajku Dokerów 5, Gdańsk Nowy Port 80-544. Praca została zrealizowana w 2020 roku w technice olejnej na płótnie. Jest to kompozycja złożona z dwudziestu części o wymiarach 38 x 55 cm. Wymiary pracy: 167 x 295 cm. Czas trwania wystawy: 6 marca - 28 czerwca 2020.

  • ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
    • Wojciech Bąk
    • Piotr Dulian
    • Barbara Garbarz-Glos
    • Dionizy Czekaj
    • Agata Lisińska-Czekaj
    2020 Pełny tekst ARCHIVES OF METALLURGY AND MATERIALS

    Polycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure and morphology of the investigated samples were characterized by an X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterization of electrical properties of the ceramics within the temperature range from –130°C to 250°C were performed by means of a dielectric spectroscopy method at the frequency ranging from 0.1 Hz to 10 MHz. The diffusion of the paraelectric – ferroelectric phase transition and dielectric relaxation for ceramic samples are described.

  • Ambisoniczna mapa wybranych miejsc w Trójmieście
    • Cezary Pietrzak
    • Piotr Odya
    2020 Pełny tekst

    Projekt miał na celu stworzenie ambisonicznej mapy Trójmiasta w formie aplikacji internetowej. Materiały wideo w technologii 360 z dźwiękiem w postaci sygnału ambisonicznego zostały zarejestrowane w lokalizacjach Trójmiasta, które uznano za charakterystyczne dla tej aglomeracji. Celem badawczym projektu było porównanie dostępnych algorytmów miksowania sygnałów ambisonicznych poprzez przeprowadzenie testów odsłuchowych. Przeprowadzono test porównań parami, aby uzyskać informacje o preferencjach odnośnie występowania w nagraniach ambisonicznych dodatkowego podkładu stereo oraz jego poziomu głośności. W drugim z testów zbada-no jaki wpływ na odbiór nagrania ambisonicznego ma sposób oraz stopień jego przetwarzania. Wnioski otrzymane poprzez analizę wyników obu testów posłużyły jako wskazówki przy post-produkcji nagrań. Otrzymane materiały zostały zamieszczone na interaktywnej mapie w aplikacji internetowej.

  • Ammonia amendment promotes high rate lactate production and recovery from semi-continuous food waste fermentation
    • Author links open overlay panelWenjuan Zhang
    • Xiang Li
    • Ya He
    • Xianbao Xu
    • Hong Chen
    • Ai Zhang
    • Yanan Liu
    • Gang Xue
    • Jacek Mąkinia
    2020 BIORESOURCE TECHNOLOGY

    In this study, a reliable approach using ammonia nitrogen was proposed to increase lactate production during semi-continuous food waste (FW) fermentation under mesophilic conditions. Both free ammonia nitrogen (FAN) and ammonium ion (NH4+-N) were present in mesophilic reactors, with a wide FAN/NH4+-N ratio variation due to the intermittent pH control. The investigation of responsible mechanisms revealed that the increased production yield of LA was associated with the acceleration of solubilization, hydrolysis, glycolysis and acidification. The presence of FAN and NH4+-N in proper concentrations increased lactate production by 2.4 folds and recovered lactate production to 24.5 g COD/L from low rate control reactor (9.6 g COD/L) under mesophilic conditions. Furthermore, the microorganisms responsible for LA accumulation (Bavariicoccus, Enterococcus, Bifidobacterium and Corynebacterium) were selectively enriched, and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways associated with carbohydrate transport and LA production were enhanced in nitrogen fed reactors.

  • Ammonia Gas Sensors: Comparison of Solid-State and Optical Methods
    • Zbigniew Bielecki
    • Tadeusz Stacewicz
    • Janusz Smulko
    • Jacek Wojtas
    2020 Pełny tekst Applied Sciences-Basel

    High precision and fast measurement of gas concentrations is important for both understanding and monitoring various phenomena, from industrial and environmental to medical and scientific applications. This article deals with the recent progress in ammonia detection using in-situ solid-state and optical methods. Due to the continuous progress in material engineering and optoelectronic technologies, these methods are among the most perceptive because of their advantages in a specific application. We present the basics of each technique, their performance limits, and the possibility of further development. The practical implementations of representative examples are described in detail. Finally, we present a performance comparison of selected practical application, accumulating data reported over the preceding decade, and conclude from this comparison.

  • An ANN-Based Approach for Prediction of Sufficient Seismic Gap between Adjacent Buildings Prone to Earthquake-Induced Pounding
    • Seyed Mohammad Khatami
    • Hosein Naderpour
    • Seyed Mohammad Nazem Razavi
    • Carneiro Rui Barros
    • Barbara Sołtysik
    • Robert Jankowski
    2020 Pełny tekst Applied Sciences-Basel

    Earthquake-induced structural pounding may cause major damages to structures, and therefore it should be prevented. This study is focused on using an artificial neural network (ANN) method to determine the sufficient seismic gap in order to avoid collisions between two adjacent buildings during seismic excitations. Six lumped mass models of structures with a different number of stories (from one to six) have been considered in the study. The earthquake characteristics and the parameters of buildings have been defined as inputs in the ANN analysis. The required seismic gap preventing pounding has been firstly determined for specified structural arrangements and earthquake records. In order to validate the method for other structural parameters, the study has been further extended for buildings with different values of height, mass, and stiffness of each story. Finally, the parametric analysis has been conducted for various earthquakes scaled to different values of the peak ground acceleration (PGA). The results of the verification and validation analyses indicate that the determined seismic gaps are large enough to prevent structural collisions, and they are just appropriate for all different structural arrangements, seismic excitations, and structural parameters. The results of the parametric analysis show that the increase in the PGA of earthquake records leads to a substantial, nearly uniform, increase in the required seismic gap between structures. The above conclusions clearly indicate that the ANN method can be successfully used to determine the minimal distance between two adjacent buildings preventing their collisions during different seismic excitations.

  • An approach to constructing genuinely entangled subspaces of maximal dimension
    • Maciej Demianowicz
    • Remigiusz Augusiak
    2020 Pełny tekst Quantum Information Processing

    Genuinely entangled subspaces (GESs) are the class of completely entangled subspaces that contain only genuinely multiparty entangled states. They constitute a particularly useful notion in the theory of entanglement but also have found an application, for instance, in quantum error correction and cryptography. In a recent study (Demianowicz and Augusiak in Phys Rev A 98:012313, 2018), we have shown how GESs can be efficiently constructed in any multiparty scenario from the so-called unextendible product bases. The provided subspaces, however, are not of maximal allowable dimensions, and our aim here is to put forward an approach to building such. The method is illustrated with few examples in small systems. Connections with other mathematical problems, such as spaces of matrices of equal rank and the numerical range, are discussed.

  • An Approximation of the Zero Error Capacity by a Greedy Algorithm
    • Marcin Jurkiewicz
    2020

    We present a greedy algorithm that determines a lower bound on the zero error capacity. The algorithm has many new advantages, e.g., it does not store a whole product graph in a computer memory and it uses the so-called distributions in all dimensions to get a better approximation of the zero error capacity. We also show an additional application of our algorithm.

  • An Approximation of the Zero Error Capacity by a Greedy Algorithm.
    • Marcin Jurkiewicz
    2020

    We present a greedy algorithm that determines a lower bound on the zero error capacity. The algorithm has many new advantages, e.g., it does not store a whole product graph in a computer memory and it uses the so-called distributions in all dimensions to get a better approximation of the zero error capacity. We also show an additional application of our algorithm.

  • An Aqueous Exfoliation of WO3 as a Route for Counterions Fabrication—Improved Photocatalytic and Capacitive Properties of Polyaniline/WO3Composite
    • Mariusz Szkoda
    • Zuzanna Zarach
    • Konrad Trzciński
    • Andrzej Nowak
    2020 Pełny tekst Materials

    In this paper, we demonstrate a novel, electrochemical route of polyaniline/tungsten oxide (PANI)/WO3) film preparation. Polyaniline composite film was electrodeposited on the FTO (fluorine-doped tin oxide) substrate from the aqueous electrolyte that contained aniline (monomer) and exfoliated WO3 as a source of counter ions. The chemical nature of WO3 incorporated in the polyaniline matrix was investigated using X-ray photoelectron spectroscopy. SEM (scanning electron microscopy) showed the impact of WO3 presence on the morphology of polyaniline film. PANI/WO3 film was tested as an electrode material in an acidic electrolyte. Performed measurements showed the electroactivity of both components and enhanced electrochemical stability of PANI/WO3 in comparison with PANI/Cl. Thus, PANI/WO3 electrodes were utilized to construct the symmetric supercapacitors. The impact of capacitive and diffusion-controlled processes on the mechanism of electrical energy storage was quantitatively determined. Devices exhibited high electrochemical capacity of 135 mF cm−2 (180 F g−1) and satisfactory retention rate of 70% after 10,000 cycles. The electrochemical energy storage device exhibited 1075.6 W kg−1 of power density and 12.25 Wh kg−1 of energy density. We also investigated the photocatalytic performance of the deposited film. Photodegradation efficiencies of methylene blue and methyl orange using PANI/WO3 and PANI/Cl were compared. The mechanism of dye degradation using WO3-containing films was investigated in the presence of scavengers. Significantly higher efficiency of photodecomposition of dyes was achieved for composite films (84% and 86%) in comparison with PANI/Cl (32% and 39%) for methylene blue and methyl orange, respectively.

  • An Automatic Self-Tuning Control System Design for an Inverted Pendulum
    • Michał Waszak
    • Rafał Łangowski
    2020 Pełny tekst IEEE Access

    A control problem of an inverted pendulum in the presence of parametric uncertainty has been investigated in this paper. In particular, synthesis and implementation of an automatic self-tuning regulator for a real inverted pendulum have been given. The main cores of the control system are a swing-up control method and a stabilisation regulator. The first one is based on the energy of an inverted pendulum, whereas the second one uses the linear-quadratic regulator (LQR). Because not all of the inverted pendulum parameter values are exactly known an automatic self-tuning mechanism for designed control system has been proposed. It bases on a devised procedure for identifying parameters. The entire derived control system enables effective a pendulum swing-up and its stabilisation at an upper position. The performance of the proposed control system has been validated by simulation in Matlab/Simulink environment with the use of the inverted pendulum model as well as through experimental works using the constructed inverted pendulum on a cart.

  • An Easy and Ecological Method of Obtaining Hydrated and Non-Crystalline WO3−x for Application in Supercapacitors
    • Mariusz Szkoda
    • Zuzanna Zarach
    • Konrad Trzciński
    • Grzegorz Trykowski
    • Andrzej Nowak
    2020 Pełny tekst Materials

    In this work, we report the synthesis of hydrated and non-crystalline WO3 flakes (WO3−x) via an environmentally friendly and facile water-based strategy. This method is described, in the literature, as exfoliation, however, based on the results obtained, we cannot say unequivocally that we have obtained an exfoliated material. Nevertheless, the proposed modification procedure clearly affects the morphology of WO3 and leads to loss of crystallinity of the material. TEM techniques confirmed that the process leads to the formation of WO3 flakes of a few nanometers in thickness. X-ray diffractograms affirmed the poor crystallinity of the flakes, while spectroscopic methods showed that the materials after exfoliation were abundant with the surface groups. The thin film of hydrated and non-crystalline WO3 exhibits a seven times higher specific capacitance (Cs) in an aqueous electrolyte than bulk WO3 and shows an outstanding long-term cycling stability with a capacitance retention of 92% after 1000 chronopotentiometric cycles in the three-electrode system. In the two-electrode system, hydrated WO3−x shows a Cs of 122 F g−1 at a current density of 0.5 A g−1. The developed supercapacitor shows an energy density of 60 Whkg−1 and power density of 803 Wkg−1 with a decrease of 16% in Csp after 10,000 cycles. On the other hand, WO3−x is characterized by inferior properties as an anode material in lithium-ion batteries compared to bulk WO3. Lithium ions intercalate into a WO3 crystal framework and occupy trigonal cavity sites during the electrochemical polarization. If there is no regular layer structure, as in the case of the hydrated and non-crystalline WO3, the insertion of lithium ions between WO3 layers is not possible. Thus, in the case of a non-aqueous electrolyte, the specific capacity of the hydrated and non-crystalline WO3 electrode material is much lower in comparison with the specific capacity of the bulk WO3-based anode material

  • An Efficient Simulation Method of Massive MIMO Antenna Arrays used in 5G Mobile Phones
    • Damian Szypulski
    • Grzegorz Fotyga
    • Michał Mrozowski
    2020 Pełny tekst

    This paper deals with a model-order reduction method, applied to speed-up the simulations of MIMO antenna arrays, performed by means of finite element method. The obtained results of the numerical tests show that the described technique is reliable and considerably increases the efficiency of the standard finite element method.

  • An enhanced method in predicting tensile behaviour of corroded thick steel plate specimens by using random field approach
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2020 Pełny tekst OCEAN ENGINEERING

    The present work investigates the possibility of using random field techniques in modelling the mechanical behaviour of corroded thick steel plate specimens. The nonlinear Finite Element method, employing the explicit dynamic solver, is used to analyse the mechanical properties of typical specimens. A material model considering full nonlinearity is used to evaluate the stress-strain response. The influence of major governing parameters of both specimen dimensions and random field is investigated through the sensitivity analysis. In order to validate the proposed methodology, results are compared with available experimental data showing an excellent agreement in both mechanical properties and stress-strain relationships. Additionally, the conclusion is made that the irregularities in the corroded surface are the main factor resulting in the decrease of mechanical properties. In this way, random field modelling appeared to be a practical and fast technique for modelling the corroded surfaces of steel structures in analysing their structural behaviour.

  • An integral-differential method for impedance determination of the hydrogen oxidation process in the presence of carbon monoxide in the proton exchange membrane fuel cell
    • Kazimierz Darowicki
    • Łukasz Gaweł
    • Michał Mielniczek
    • Ewa Janicka
    • Artur Zieliński
    • Jens Mitzel
    • Jurgen Hunger
    2020 Pełny tekst INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    The impedance of a proton exchange membrane fuel cell powered by hydrogen contaminated with carbon monoxide, ranging from 150 to 300 ppb, is measured and discussed. The tested range of CO concentration complied with the fuel standard specified in the ISO standards. Studies of influence of CO contamination on operation of PEMFC are crucial for further development and commercialization of fuel cells for automotive applications. Based on the measurements made by Dynamic Electrochemical Impedance Spectroscopy (DEIS), changes in the cell impedance as a function of time were determined. An innovative integral-differential methodology for the analysis of chrono-impedance diagrams was developed, which enabled the extraction of the impedance spectra describing the anodic processes. This way of analysis is completely novel and original and it was not presented before in literature. The ability to monitor and diagnose the anode's operation under real operation conditions is demonstrated. The reversibility of the CO adsorption process and the loss of anode catalytic activity were verified. All this issues were not possible to be studied before with the use of classic impedance measurements.