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  • A Parallax Shift Effect Correction Based on Cloud Height for Geostationary Satellites and Radar Observations
    • Tomasz Bieliński
    2020 Pełny tekst Remote Sensing

    The effect of cloud parallax shift occurs in satellite imaging, particularly for high angles of satellite observations. This study demonstrates new methods of parallax effect correction for clouds observed by geostationary satellites. The analytical method that could be found in literature, namely the Vicente et al./Koenig method, is presented at the beginning. It approximates a cloud position using an ellipsoid with semi-axes increased by the cloud height. The error values of this method reach up to 50 meters. The second method, which is proposed by the author, is an augmented version of the Vicente et al./Koenig approach. With this augmentation, the error can be reduced to centimeters. The third method, also proposed by the author, incorporates geodetic coordinates. It is described as a set of equations that are solved with the numerical method, and its error can be driven to near zero by adjusting the count of iterations. A sample numerical solution procedure with application of the Newton method is presented. Also, a simulation experiment that evaluates the proposed methods is described in the paper. The results of an experiment are described and contrasted with current technology. Currently, operating geostationary Earth Observation (EO) satellite resolutions vary from 0.5 km up to 8 km. The pixel sizes of these satellites are much greater than for maximal error of the least precise method presented in this paper. Therefore, the chosen method will be important when the resolution of geostationary EO satellites reaches 50 m. To validate the parallax correction, procedure data from on-ground radars and the Meteosat Second Generation (MSG) satellite, which describes stormy events, was compared before and after correction. Comparison was performed by correlating the logarithm of the cloud optical thickness (COT) with radar reflectance in dBZ (radar reflectance – Z in logarithmic form).

  • A pilot study to assess an in-process inspection method for small diameter holes produced by Direct Metal Laser Sintering
    • Mariusz Deja
    • Dawid Zieliński
    2020 Pełny tekst RAPID PROTOTYPING JOURNAL

    Purpose The purpose of this research is to evaluate the geometric quality of small diameter holes in parts printed by DMLS technology. An in-process optical inspection method is proposed and assessed during a pilot study. The influence of the theoretical hole diameter assumed in a CAD system and the sample thickness (hole length) on the hole clearance was analysed. Design/methodology/approach The samples made of two different materials: EOS MaragingSteel MS1 and aluminium alloy EOS Aluminium consisted of straight through holes of different diameters and lengths. Dimensional and shape accuracy of the holes were determined with the use of the image processing software and the computer analysis of 2-D images. The definition of the equivalent hole diameter was proposed to calculate the hole clearance. Feret’s diameters were determined for the evaluation of the shape accuracy. Findings The dependency between the equivalent hole diameter and the theoretical diameter was approximated by the linear function for a specific sample thickness. Additionally, a general empirical model for determining the hole clearance was developed, allowing for calculating the equivalent hole diameter as a function of a sample thickness and a theoretical hole diameter. Practical implications Developed functions can be used by designers for a proper assignment of a hole diameter to achieve the required patency. The relevant procedures and macros based on proposed empirical models can be embedded in CAD systems to support the designing process. Originality/value The analysis of the geometric quality of the holes in parts printed by DMLS was based on the computer analysis of 2-D images. The proposed method of assessing the shape accuracy of straight through holes is relatively cheap, is widely available and can be applied to the features of other shapes produced by 3D printing.

  • A Population-Based Method with Selection of a Search Operator
    • Krystian Łapa
    • Krzysztof Cpałka
    • Tacjana Niksa-Rynkiewicz
    • Wang Lipo
    2020

    This paper presents a method based on a population in which the parameters of individuals can be processed by operators from various population-based algorithms. The mechanism of selecting operators is based on the introduction of an additional binary parameters vector located in each individual, on the basis of which it is decided which operators are to be used to modify individuals’ parameters. Thus, in the proposed approach, many operators can be used simultaneously for this purpose. As part of the paper various methods of initializing binary parameters, various population sizes, and their impact on the operation of the algorithm were tested. The simulation was carried out on a wellknown set of benchmark functions.

  • A pore-scale thermo–hydro-mechanical model for particulate systems
    • Robert Caulk
    • Luc Sholtès
    • Marek Krzaczek
    • Bruno Chareyre
    2020 COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING

    A pore scale numerical method dedicated to the simulation of heat transfer and associated thermo–hydro-mechanical couplings in granular media is described. The proposed thermo–hydro-mechanical approach builds on an existing hydromechanical model that employs the discrete element method for simulating the mechanical behavior of dense sphere packings and combines it with the finite volume method for simulating pore space fluid flow and the resulting hydro-mechanical coupling. Within the hydro-mechanical framework, the pore space is discretized as a tetrahedral network whose geometry is defined by the triangulation of discrete element method (DEM) particle centers. It is this discretization of DEM particle contacts and tetrahedral pore spaces that enables the efficient conductive and advective heat transfer models proposed herein. In particular, conductive heat transfer is modeled explicitly between and within solid and fluid phases: across DEM particle contacts, between adjacent tetrahedral pores, and between pores and incident particles. Meanwhile, advective heat transfer is added to the existing implicit fluid flow scheme by estimating mass–energy–flux from pressure induced fluid fluxes. In addition to the heat transfer model, a thermo-mechanical coupling is implemented by considering volume changes based on the thermal expansion of particles and fluid. The conduction and advection models are verified by presenting comparisons to an analytical solution for conduction and a fully resolved numerical solution for conduction and advection. Finally, the relevance of the fully coupled thermo–hydro-mechanical model is illustrated by simulating an experiment where a saturated porous rock sample is subjected to a cyclic temperature loading.

  • A Power-Efficient Digital Technique for Gain and Offset Correction in Slope ADCs
    • Miron Kłosowski
    2020 Pełny tekst IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS

    In this brief, a power-efficient digital technique for gain and offset correction in slope analog-to-digital converters (ADCs) has been proposed. The technique is especially useful for imaging arrays with massively parallel image acquisition where simultaneous compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. The presented approach is based on stopping the ADC clock by a specially prepared clock-enable pulse sequence. This brief describes the properties of ADCs utilizing this clock stopping technique, including power dissipation, integral, and differential nonlinearity. The experimental validation has been performed for the ASIC implementation of the 128-pixel imager containing photo-sensors integrated with ADCs. Finally, a modification is proposed that increases the accuracy of the gain correction. Measurements confirm functionality of the proposed approach. Reduction of the PRNU (to ~0.4 LSB) has been achieved as well.

  • A Preliminary Study and Analysis of Tidal Stream Generators
    • Saad bin Abul Kashem
    • Molla E. Majid
    • Mujahid Tabassum
    • Azad Ashraf
    • Jarosław Guziński
    • Krzysztof Łuksza
    2020 Pełny tekst Acta Energetica

    For a sustainable future, tidal energy can play a vital role. Tidal energy relies on the gravitational pull of the Moon and the Sun along with the centrifugal forces created by the Earth. Tidal barrage uses the potential energy from the tide and has been very successful in electricity production. With the help of a turbine, kinetic energy can also be harnessed from tidal currents to generate electricity. However, it is not economically feasible to use this type of technology for large scale production of electrical energy. It is important to note that the development of this technology is still in the early stage. This research paper provides a preliminary discussion of tidal energy generation using a few different technologies. Initial research has been done using Computational Fluid Dynamics and SolidWorks software on the tidal stream generator and tidal barrage system. Some of the key challenges are also identified in terms of the development of the tidal energy conversion system.

  • A Proposed Machine Learning Model for Forecasting Impact of Traffic-Induced Vibrations on Buildings
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2020

    Traffic-induced vibrations may cause various damages to buildings located near the road, including cracking of plaster, cracks in load-bearing elements or even collapse of the whole structure. Measurements of vibrations of real buildings are costly and laborious. Therefore the aim of the research is to propose the original numerical algorithm which allows us to predict, with high probability, the nega-tive dynamic impact of traffic-induced vibrations on the examined building. The model has been based on machine learning. Firstly, the experimental tests have been conducted on different buildings using specialized equipment taking into ac-count six factors: distance from the building to the edge of the road, type of sur-face, condition of road surface, condition of the building, the absorption of soil and the type of vehicle. Then, the numerical algorithm based on machine learning (using support vector machine) has been created. The results of the conducted analysis clearly show that the method can be considered as a good tool for pre-dicting the impact of traffic-induced vibrations on buildings, being characterized by high reliability.

  • A Proposed Soft Computing Model for Ultimate Strength Estimation of FRP-Confined Concrete Cylinders
    • Reza Kamgar
    • Hosein Naderpour
    • Houman Ebrahimpour Komeleh
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2020 Pełny tekst Applied Sciences-Basel

    In this paper, the feed-forward backpropagation neural network (FFBPNN) is used to propose a new formulation for predicting the compressive strength of fiber-reinforced polymer (FRP)-confined concrete cylinders. A set of experimental data has been considered in the analysis. The data include information about the dimensions of the concrete cylinders (diameter, length) and the total thickness of FRP layers, unconfined ultimate concrete strength, ultimate confinement pressure, ultimate tensile strength of the FRP laminates and the ultimate concrete strength of the concrete cylinders. The confined ultimate concrete strength is considered as the output data, while other parameters are considered as the input data. These parameters are mostly used in existing FRP-confined concrete models. Soft computing techniques are used to estimate the compressive strength of FRP-confined concrete cylinders. Finally, a new formulation is proposed. The results of the proposed formula are compared to the existing methods. To verify the proposed method, results are compared with other methods. The results show that the described method can forecast the compressive strength of FRP-confined concrete cylinders with high precision in comparison with the existing formulas. Moreover, the mean percentage of error for the proposed method is very low (3.49%). Furthermore, the proposed formula can estimate the ultimate compressive capacity of FRP-confined concrete cylinders with a different type of FRP and arbitrary thickness in the initial design of practical projects.

  • A Rapid and Simple Method for Screening Microorganisms with a Potential for Catechol Biodegradation
    • Natalia Filipowicz
    • Hubert Cieśliński
    2020 International Journal of Environmental Research

    Catechol is a highly toxic compound that is also a key intermediate in biodegradation pathways of various aromatic compounds. In this paper, a new screening method for isolation of microorganisms with the potential for catechol biodegradation is reported. The method described is based on the ability of catechol to form a color complex with Fe3+ ions. For this purpose, basal medium that is widely used for classification of microorganisms by carbon requirements was used. Specifically, minimal Bushnell Haas medium plates supplemented with catechol at 500 mg l−1 concentration were used for both yeast and bacteria cultivation. After appearance of microorganism colonies on the growth medium, each plate was flooded with 7.0 ml of 5% (w/v) of FeCl3 and incubated for a period of 5 min at room temperature. Flooding with this solution led to the formation of a green color from Fe3+-catechol complexes in the growth medium and an appearance of clear zones around colonies of microorganisms that utilize catechol as a sole source of carbon. Based on this, the presented method could be useful as a screening step for microorganisms with a potential for catechol biodegradation.

  • A rapid dispersive liquid–liquid microextraction of antimicrobial onion organosulfur compounds in animal feed coupled to gas chromatography-mass spectrometry
    • Marta Pastor-belda
    • Natalia Arroyo-manzanares
    • Kateryna Yavir
    • Paloma Abad
    • Natalia Campillo
    • Manuel Hernandez-Cordoba
    • Pilar Vinas
    2020 Analytical Methods

    A rapid analytical procedure is proposed for determining two antimicrobial onion organosulfur compounds, propyl disulfide (PDS) and propyl propane thiosulfonate (PTSO), in animal feed. The use of PTSO as a natural ingredient in animal feed is allowed due to its antimicrobial activity against pathogenic organisms. Two analytical methodologies using gas chromatography coupled to mass spectrometry (GC-MS) are compared. After the extraction of the compounds from animal feed with acetonitrile, dispersive solid phase extraction (DSPE) as a cleaning stage with C18, or dispersive liquid–liquid microextraction (DLLME), using 100 mL of CHCl3, was tried. Both the methods were validated using a pig feed sample and the best results were achieved by DLLME. This technique provided cleaner extracts, five-times greater linear ranges and lower detection limits than simple cleaning due to the enrichment factor achieved. The relative standard deviation decreased from 22% with DSPE to 13% with DLLME. The usefulness of the DLLME-GC-MS methodology was tested by analysing 10 different samples of chicken, calf, hen, cow and fish feed. The concentrations of PDS were in the 0.1–1.7 mg g1 range and those of PTSO were between 0.09 and 2.1 mg g-1

  • A reactive algorithm for deducing nodal forwarding behavior in a multihop ad-hoc wireless network in the presence of errors
    • Karol Rydzewski
    • Jerzy Konorski
    2020 Pełny tekst International Journal of Electronics and Telecommunications

    A novel algorithm is presented to deduce individual nodal forwarding behavior from standard end-to-end acknowledgments. The algorithm is based on a well-established mathematical method and is robust to network related errors and nodal behavior changes. The proposed solution was verified in a network simulation, during which it achieved sound results in a challenging multihop ad-hoc network environment.

  • A Review of Emotion Recognition Methods Based on Data Acquired via Smartphone Sensors
    • Agata Kołakowska
    • Wioleta Szwoch
    • Mariusz Szwoch
    2020 Pełny tekst SENSORS

    In recent years, emotion recognition algorithms have achieved high efficiency, allowing the development of various affective and affect-aware applications. This advancement has taken place mainly in the environment of personal computers offering the appropriate hardware and sufficient power to process complex data from video, audio, and other channels. However, the increase in computing and communication capabilities of smartphones, the variety of their built-in sensors, as well as the availability of cloud computing services have made them an environment in which the task of recognising emotions can be performed at least as effectively. This is possible and particularly important due to the fact that smartphones and other mobile devices have become the main computer devices used by most people. This article provides a systematic overview of publications from the last 10 years related to emotion recognition methods using smartphone sensors. The characteristics of the most important sensors in this respect are presented, and the methods applied to extract informative features on the basis of data read from these input channels. Then, various machine learning approaches implemented to recognise emotional states are described.

  • A screening of select toxic and essential elements and persistent organic pollutants in the fur of Svalbard reindeer
    • Aneta Pacyna-Kuchta
    • Paulina Wietrzyk-Pełka
    • Michał Węgrzyn
    • Marcin Frankowski
    • Żaneta Polkowska
    2020 Pełny tekst CHEMOSPHERE

    Reindeers play an important role in the polar ecosystem, being long-lived sole vegetarians feeding on local vegetation. They can be used as a valuable bioindicator, helping us to understand contaminants’ impact on the polar terrestrial ecosystem. Still, scarce data exist from research in which polar herbivores (especially those from the European parts of the Arctic) were a major study subject for trace elements and persistent organic pollutant determination. Here, Svalbard reindeer fur has been used to determine metals, non-metals and metalloids using ICP-MS, and several persistent organic pollutants including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) using gas chromatography coupled to a tandem mass spectrometer (GC-MS/MS). Samples were collected from reindeer populations living in the area near Ny-Ålesund and Longyearbyen. Essential elements like Fe, Mg, Zn, K, Ca, Cu predominated in the trace elements profile. Median values of As, Cd, Co, Li, Ni, Se and V were all below 0.5 mg/g dw. Mercury was below detection limit in all samples, while the Pb median varied from 0.35 to 0.74 mg/g dw. Except acenaphthylene and fluorene, PAHs were detectable only in samples collected in the vicinity of Longyearbyen. Of 15 studied pesticides, only DDT and its metabolites were above the detection limit, and, of PCBs, only PCB28.

  • A shear stress micromodel of urinary tract infection by the Escherichia coli producing Dr adhesin
    • Beata Zalewska-Piątek
    • Marcin Olszewski
    • Tomasz Lipniacki
    • Sławomir Błoński
    • Miłosz Wieczór
    • Piotr Bruździak
    • Anna Skwarska
    • Bogdan Nowicki
    • Stella Nowicki
    • Rafał Piątek
    2020 Pełny tekst PLoS Pathogens

    In this study, we established a dynamic micromodel of urinary tract infection to analyze the impact of UT-segment-specific urinary outflow on the persistence of E. coli colonization. We found that the adherence of Dr+ E. coli to bladder T24 transitional cells and type IV collagen is maximal at lowest shear stress and is reduced by any increase in flow velocity. The analyzed adherence was effective in the whole spectrum of physiological shear stress and was almost irreversible over the entire range of generated shear force. Once Dr+ E. coli bound to host cells or collagen, they did not detach even in the presence of elevated shear stress or of chloramphenicol, a competitive inhibitor of binding. Investigating the role of epithelial surface architecture, we showed that the presence of budding cells–a model microarchitectural obstacle–promotes colonization of the urinary tract by E. coli. We report a previously undescribed phenomenon of epithelial cell “rolling-shedding” colonization, in which the detached epithelial cells reattach to the underlying cell line through a layer of adherent Dr+ E. coli. This rolling-shedding colonization progressed continuously due to “refilling” induced by the flow-perturbing obstacle. The shear stress of fluid containing free-floating bacteria fueled the rolling, while providing an uninterrupted supply of new bacteria to be trapped by the rolling cell. The progressive rolling allows for transfer of briefly attached bacteria onto the underlying monolayer in a repeating cascading event.

  • A simple model of the trap-assisted recombination with the excitonic Auger mechanism
    • Jędrzej Szmytkowski
    2020 Pełny tekst European Physical Journal Plus

    We present a simple model of the trap-assisted recombination combined with the excitonic Auger mechanism. It has been shown that only six independent transitions of electrons and holes should be taken into account to describe a combination of the Shockley–Read–Hall (SRH) recombination with this excitonic process. This is in opposition to a well-known model of the SRH mechanism with the free carriers Auger effect via deep states, where eight separated transitions take place. The derived equation for the effective recombination rate can be useful for modeling the excitonic processes in semiconductors, especially in photovoltaic and optoelectronic devices.

  • A space-efficient algorithm for computing the minimum cycle mean in a directed graph
    • Paweł Pilarczyk
    2020 Journal of Mathematics and Computer Science-JMCS

    An algorithm is introduced for computing the minimum cycle mean in a strongly connected directed graph with n vertices and m arcs that requires O(n) working space. This is a considerable improvement for sparse graphs in comparison to the classical algorithms that require O(n^2) working space. The time complexity of the algorithm is still O(nm). An implementation in C++ is made publicly available at http://www.pawelpilarczyk.com/cymealg/.

  • A strong preference for the TA/TA dinucleotide step discovered for an acridine-based, potent antitumor dsDNA intercalator, C-1305: NMR-driven structural and sequence-specificity studies
    • Tomasz Laskowski
    • Witold Andrałojć
    • Jakub Grynda
    • Paulina Gwarda
    • Jan Mazerski
    • Zofia Gdaniec
    2020 Pełny tekst Scientific Reports

    Triazoloacridinone C-1305, a potent antitumor agent recommended for Phase I clinical trials, exhibits high activity towards a wide range of experimental colon carcinomas, in many cases associated with complete tumor regression. C-1305 is a well-established dsDNA intercalator, yet no information on its mode of binding into DNA is available to date. Herein, we present the NMR-driven and MD-refined reconstruction of the 3D structures of the d(CGATATCG)2:C-1305 and d(CCCTAGGG)2:C-1305 non-covalent adducts. In both cases, the ligand intercalates at the TA/TA site, forming well-defined dsDNA:drug 1:1 mol/mol complexes. Orientation of the ligand within the binding site was unambiguously established by the DNA/ligand proton-proton NOE contacts. A subsequent, NMR-driven study of the sequence-specificity of C-1305 using a series of DNA duplexes, allowed us to confirm a strong preference towards TA/TA dinucleotide steps, followed by the TG/CA steps. Interestingly, no interaction at all was observed with duplexes containing exclusively the AT/AT, GG/CC and GA/TC steps.

  • A Study of Cross-Linguistic Speech Emotion Recognition Based on 2D Feature Spaces
    • Gintautas Tamulevicius
    • Grazina Korvel
    • Anil Bora Yayak
    • Povilas Treigys
    • Jolita Bernataviciene
    • Bożena Kostek
    2020 Pełny tekst Electronics

    In this research, a study of cross-linguistic speech emotion recognition is performed. For this purpose, emotional data of different languages (English, Lithuanian, German, Spanish, Serbian, and Polish) are collected, resulting in a cross-linguistic speech emotion dataset with the size of more than 10.000 emotional utterances. Despite the bi-modal character of the databases gathered, our focus is on the acoustic representation only. The assumption is that the speech audio signal carries sufficient emotional information to detect and retrieve it. Several two-dimensional acoustic feature spaces, such as cochleagrams, spectrograms, mel-cepstrograms, and fractal dimension-based space, are employed as the representations of speech emotional features. A convolutional neural network (CNN) is used as a classifier. The results show the superiority of cochleagrams over other feature spaces utilized. In the CNN-based speaker-independent cross-linguistic speech emotion recognition (SER) experiment, the accuracy of over 90% is achieved, which is close to the monolingual case of SER.

  • A study of the kinetics of bismuth telluride synthesis by an oxide reduction method
    • Bartosz Jakub Trawiński
    • Beata Bochentyn
    • Marcin Stanisław Łapiński
    • Bogusław Kusz
    2020 Pełny tekst THERMOCHIMICA ACTA

    The kinetics of a reduction of bismuth and tellurium oxides in a hydrogen atmosphere, leading to the formation of thermoelectric bismuth telluride is investigated. The evaluation of the reaction kinetics was based on a thermogravimetric analysis performed in non-isothermal conditions. A non-parametric analysis method and the Friedman method were used for the evaluation of the data. Additionally, for a better understanding of the process, reactions of the reduction of Bi2O3, TeO2 as well as Bi2Te2O7 and Bi2Te4O11, which are formed as intermediate products, were investigated. The activation energies calculated for the reactions were between 56 kJ/mol in the case of the Bi2Te2O7 reduction and 100 kJ/mol for the reduction of mixed oxides. No correlation between the activation energy and the Bi:Te ratio in the reduced material was found. The calculated conversion functions also differed between the investigated reactions. A self-heating process was found for TeO2 and Bi2Te4O11 reduction reactions. In the case of the tellurium oxide, it was assigned to the melting of Te nanoparticles. These effects were also found to enhance the synthesis of Bi2Te3 by the reduction of mixed bismuth and tellurium oxides. The resulting thermoelectric material was found to be completely reduced, with no traces of oxygen in the XPS spectrum. EDX mapping of the cross-section of material’s grains revealed a homogenous distribution of elements in the final product.

  • A study on fibre-reinforced concrete elements properties based on the case of habitat modules in the underwater sills
    • Marzena Kurpińska
    • Beata Grzyl
    • Adam Kristowski
    2020 Pełny tekst Polish Maritime Research

    Hydrotechnical constructions are mostly objects functioning in extreme conditions and requiring a custom-made construction project. In the case of using prefabricated elements, it is required to develop production, transport, assembly, conservation and repair technology. Concerning the problem of concrete cracks, modern repair systems allow positive effects to be achieved in many cases of concrete elements repair. In this work an attempt has been made to assess the properties of concrete, situated in the Baltic Sea environment, in which traditional rebar was partly replaced by dispersed fibre-phase. Fibre-reinforced concrete belongs to the group of composite materials. The presence of fibres helps to increase the tensile strength, flexural strength and resilience and also prevents the appearance of cracks. In the given paper we will also discuss basic parameters of steel and polymer fibres and the influence of both types of fibres on the maturing and hardened concrete. In this work special attention has been paid to the advantages of polypropylene and polymer fibres with regard to commonly-known steel fibres. The use of synthetic fibres will be advantageous in constructions where the reduction of shrinkage cracks and high resilience are essential. On top of that, the use of synthetic fibres is highly recommended when constructing objects that will be exposed to the impact of an aggressive environment. Undoubtedly, polymer fibres are resistant to the majority of corrosive environments. Fibre-reinforced concretes are a frequently implemented construction solution. The possibility of concrete modification allows the emergence of new construction materials with improved physical-mechanical properties, under the condition of being applied relevantly.

  • A Subspace-Splitting Moment-Matching Model-Order Reduction Technique for Fast Wideband FEM Simulations of Microwave Structures
    • Damian Szypulski
    • Grzegorz Fotyga
    • Valentin de la Rubia
    • Michał Mrozowski
    2020 Pełny tekst IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    This article describes a novel model-order reduction (MOR) approach for efficient wide frequency band finite-element method (FEM) simulations of microwave components. It relies on the splitting of the system transfer function into two components: a singular one that accounts for the in-band system poles and a regular part that has no in-band poles. In order to perform this splitting during the reduction process, the projection basis is formed of two sets of orthogonal vectors that must be computed in sequence. The first set to be computed consists of the in-band eigenvectors that are associated with the dynamics of the electromagnetic field, while the second set uses the block moments of the original system, which are computed in the orthogonal complement to the subspace spanned by the in-band eigenvectors. The advantage of this method is that it results in a more compact reduced-order model than a method that employs only moment matching for the projection basis computations.

  • A survey of neural networks usage for intrusion detection systems
    • Anna Drewek-Ossowicka
    • Mariusz Pietrołaj
    • Jacek Rumiński
    2020 Pełny tekst Journal of Ambient Intelligence and Humanized Computing

    In recent years, advancements in the field of the artificial intelligence (AI) gained a huge momentum due to the worldwide appliance of this technology by the industry. One of the crucial areas of AI are neural networks (NN), which enable commer‐ cial utilization of functionalities previously not accessible by usage of computers. Intrusion detection system (IDS) presents one of the domains in which neural networks are widely tested for improving overall computer network security and data privacy. This article gives a thorough overview of recent literature regarding neural networks usage in intrusion detection system area, including surveys and new method proposals. Short tutorial descriptions of neural network architectures, intrusion detection system types and training datasets are also provided.

  • A Theoretical and Experimental Study of Moderate Temperature Alfa Type Stirling Engines
    • Jacek Kropiwnicki
    • Mariusz Furmanek
    2020 Pełny tekst ENERGIES

    The Stirling engine is a device that allows conversion of thermal energy into mechanical energy with relatively high efficiency. Existing commercial designs are mainly based on the usage of high temperature heat sources, whose availability from renewable or waste heat sources is significantly lower than that of moderate temperature sources. The paper presents the results of experimental research on a prototype alpha type Stirling engine powered by a moderate temperature source of heat. Obtained results enabled calibration of the evaluated theoretical model of the Stirling engine. The model of the engine has been subsequently used for the analysis of regenerator effectiveness influenced by the charge pressure and the heating temperature. Performed study allowed to determine further development directions of the prototype engine to improve its power and efficiency. As a result of optimization, worked out design will potentially increase the indicated efficiency up to 19.5% (5.5% prototype) and the indicated power up to 369 W (114 W prototype).

  • 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.