Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • Design of a compact planar transmission line for miniaturized rat-race coupler with harmonics suppression
    • Ali Lalbakhsh
    • Golshan Mohamadpour
    • Saeed Roshani
    • Mohammad Ami
    • Sobhan Roshani
    • Abu Sadat Sayem
    • Mohammad Alibakhshikenari
    • Sławomir Kozieł
    2021 Pełny tekst IEEE Access

    This paper presents an elegant yet straightforward design procedure for a compact rat-race coupler (RRC) with an extended harmonic suppression. The coupler’s conventional λ/4 transmission lines (TLs) are replaced by a specialized TL that offers significant size reduction and harmonic elimination capabilities in the proposed approach. The design procedure is verified through the theoretical, circuit, and electromagnetic (EM) analyses, showing excellent agreement among different analyses and the measured results. The circuit and EM results show that the proposed TL replicates the same frequency behaviour of the conventional one at the design frequency of 1.8 GHz while enables harmonic suppression up to the 7th harmonic and a size reduction of 74%. According to the measured results, the RRC has a fractional bandwidth of 20%, with input insertion losses of around 0.2 dB and isolation level better than 35 dB. Furthermore, the total footprint of the proposed RRC is only 31.7 mm × 15.9 mm, corresponding to 0.28 λ × 0.14 λ, where λ is the guided wavelength at 1.8 GHz.

  • Design of a Patch Power Divider with Simple Structure and Ultra-Broadband Harmonics Suppression
    • Saeed Roshani
    • Sławomir Kozieł
    • Sobhan Roshani
    • Mohammad Jamshidi
    • Fariborz Parandin
    • Stanisław Szczepański
    2021 Pełny tekst IEEE Access

    This paper introduces a simple H-shaped patch Wilkinson power divider (WPD), which provides ultra wide harmonics suppression band. The presented WPD designed at 1.8 GHz, and exhibits good performance at the operating bandwidth. In the proposed divider structure, two simple patch low-pass filters (LPFs) are employed at each branch, and three open ended stubs are added at each port. The proposed divider, implemented using the aforementioned structures has a good performance at both higher frequencies, and the operating frequency. In particular, the designed divider provides an ultra wide suppression band from 3 GHz to 20 GHz, which encompasses the 2nd up to the 11th harmonic. The proposed WPD has an operating band from 1.62 GHz to 2.1 GHz, with the operating bandwidth exceeding 480 MHz. Consequently, the fractional bandwidth (FBW) of 25.8 percent is obtained. The results indicate |S11|, |S12|, |S22|, and |S23|, are equal to –17 dB, –3.5 dB, –20 dB, and –17 dB, respectively, at the operating frequency. The simulation results are corroborated through the measurements of the fabricated divider prototype. The superior harmonic suppression capability is also demonstrated through comparisons with state-of-the-art divider circuits from the literature.

  • Design of experiments approach for ultimate strength assessment of corroded stiffened plates
    • Krzysztof Wołoszyk
    • Yordan Garbatov
    2021 Pełny tekst

    The impact of corrosion degradation on the ultimate strength of stiffened plates subjected to compressive loading is investigated. The DoE technique is used considering different plate and column slenderness ratios and corrosion severity. The FE method, considering geometrical and material nonlinearities, is employed. A two-stage corrosion degradation model is adopted. Firstly, a uniform thickness loss is adopted to reflect the mean loss of the volume of material. Secondly, mechanical properties are reduced, to reflect the local non-uniformity of the corroded surface, leading to a local strain reduction when compared to a smooth surface plate. As an analysis outcome, the most important governing factors and interactions between them are obtained. The post-collapse shapes are presented and discussed. The resulting structural response surface allows for fast estimation of the ulti-mate strength of corroded stiffened plate, revealing to be a swift and practical tool to be adopted in the engineering practice.

  • Design of High-Performance Scattering Metasurfaces through Optimization-Based Explicit RCS Reduction
    • Sławomir Kozieł
    • Muhammad Abdullah
    • Stanisław Szczepański
    2021 Pełny tekst IEEE Access

    The recent advances in the development of coding metasurfaces created new opportunities in realization of radar cross section (RCS) reduction. Metasurfaces, composed of optimized geometries of meta-atoms arranged as periodic lattices, are devised to obtain desired electromagnetic (EM) scattering characteristics. Despite potential benefits, their rigorous design methodologies are still lacking, especially in the context of controlling the EM wavefront through parameter tuning of meta-atoms. One of the practical obstacles hindering efficient design of metasurfaces is implicit handling of RCS performance. To achieve essential RCS reduction, the design task is normally formulated in terms of phase reflection characteristics of the meta-atoms, whereas their reflection amplitudes—although contributing to the overall performance of the structure—is largely ignored. As a result, the conventional approaches are unable to determine truly optimum solutions. This article proposes a novel formulation of the metasurface design task with explicit handling of RCS reduction at the level of meta-atoms. Our methodology accounts for both the phase and reflection amplitudes of the unit cells. The design objective is defined to directly optimize the RCS reduction bandwidth at the specified level (e.g., 10 dB) w.r.t. the metallic surface. The benefits of the presented scheme are twofold: (i) it provides a reliable insight into the metasurface properties even though the design process is carried out at the level of meta-atoms, (ii) the obtained design requires minimum amount of tuning at the level of the entire metasurface. None of these is possible for phase-response-based approach fostered in the literature. For practical purposes, the design is conducted using a surrogate-assisted procedure involving kriging metamodels, which enables global optimization at a low computational cost. To corroborate the utility of our formulation, a high-performance metasurface incorporating crusader-cross-shaped meta-atoms has been developed. The obtained results indicate that the system characteristics predicted at the design stage are well aligned with those of the EM-simulated structure (which is not the case for the traditional design approach). The metasurface features 10-dB RCS reduction in the frequency range of 16.5 GHz to 34.6 GHz, as validated both numerically and experimentally.

  • Design of Intelligent Low-Voltage Load Switch for Remote Control System in Smart Grid
    • Dezhi Xiong
    • Xiangqun Chen
    • Radek Martinek
    • He Wen
    • Derong Luo
    • Janusz Smulko
    2021 Pełny tekst Iranian Journal of Science and Technology-Transactions of Electrical Engineering

    Current low-voltage load switches do not support remote disconnect/connect and real-time monitoring of a disconnect/connect state. Addressing to these issues, this paper presents a low-voltage load switch for a smart remote control system, which uses a one-chip microcontroller board and a DC step motor drive mechanism and provides the feedback on the switch status also. Arrears disconnect and full-pay connect control is implemented via the microcomputer and Hall sensor. The low-power supply and state feedback circuit are designed to reduce the power consumption. And the motor drive mechanism is optimized to improve the performance of motor. Finally, a test environment includes the system control and feedback is created to illustrate the feasibility of the designed low-voltage switch. The test results that the design supports disconnect/connect control and state feedback in various conditions validate the feasibility of this designed system, which has high practical value and is worthy of promotion.

  • Design of weighted PID controllers for control of the Stewart-Gough platform
    • Justyna Kolasiewicz
    • Anna Perżyło
    • Robert Piotrowski
    2021

    Stewart-Gough platform (SGP) is a popular parallel type manipulator that involves a 6 degrees of freedom (DOF) motion. In this paper, the process of mathematical modelling of SGP is presented. Two selected control algorithms that use PID controllers and weighted PID controllers are designed. Both control systems using these algorithms are implemented in MATLAB environment as well as on the actual SGP. Parameters of the controllers are optimized with the use of different integral performance criteria. Tests of the designed control systems on the computer model and on the SGP are presented.

  • Design principles for creating digital transparency in government
    • Ricardo Matheus
    • Marijn Janssen
    • Tomasz Janowski
    2021 Pełny tekst GOVERNMENT INFORMATION QUARTERLY

    Under pressure to fight corruption, hold public officials accountable, and build trust with citizens, many governments pursue the quest for greater transparency. They publish data about their internal operations, externalize decision-making processes, establish digital inquiry lines to public officials, and employ other forms of transparency using digital means. Despite the presence of many transparency-enhancing digital tools, putting such tools together to achieve the desired level of digital transparency, to design entire government systems for digital transparency, remains challenging. Design principles and other design guides are lacking in this area. This article aims to fill this gap. We identify a set of barriers to digital transparency in government, define 16 design principles to overcome such barriers, and evaluate these principles using three case studies from different countries. Some principles apply to projects, others to systems, yet others to entire organizations. To achieve digital transparency, before building and deploying digital solutions, government organizations should build technological and institutional foundations and use such foundations to organize themselves for transparency. The proposed design principles can help develop and apply such foundations.

  • Designing acoustic scattering elements using machine learning methods
    • Adam Kurowski
    2021 Pełny tekst

    In the process of the design and correction of room acoustic properties, it is often necessary to select the appropriate type of acoustic treatment devices and make decisions regarding their size, geometry, and location of the devices inside the room under the treatment process. The goal of this doctoral dissertation is to develop and validate a mathematical model that allows predicting the effects of the application of the scattering system in selected points of the room. Further, it is aimed to use this model in the process of computer optimization of the room sound treatment process. The means for achieving these goals are machine learning algorithms with a particular focus on deep learning and reinforcement learning. Deep machine learning models are trained by using computer simulation employing the finite difference method (FDTD), which is used as a source of the reward signal. The simulation model is based on the modified difference equations derived by the author of this thesis that allows simulating the behavior of acoustic diffusers in anechoic conditions. In order to reproduce this type of conditions, the results obtained by the reinforcement learning algorithms, in particular - by the deep policy gradient algorithm, were compared with the results obtained with the classical methods of designing acoustic diffusers and those obtained using another optimization method, i.e., genetic algorithms, where the numerical simulation of the behavior of the acoustic diffuser serves to calculate the value of the fitness function, which plays a role analogous to the reward function. The optimized property of acoustic diffusers is the autocorrelation diffusion coefficient. Numerical experiments have shown that optimization algorithms can be used to maximize the metrics computed by numerical simulation. The best results were obtained with the reinforcement learning algorithms. To validate the calculation results, the measurement of acoustic diffuser prototypes was also performed in the anechoic chamber. As a result of the measurements, the thesis confirmed that the algorithms resulting from computer optimization are characterized by more desirable parameters - the broadband autocorrelation diffusion coefficient and the band diffusion coefficients calculated for the bands with central frequencies with the values from 250 Hz up to 4 kHz. The proposed algorithm is a new approach to the intelligent design of acoustic systems to improve room acoustic properties.

  • Designing Control and Protection Systems with Regard to Integrated Functional Safety and Cybersecurity Aspects
    • Marcin Śliwiński
    • Emilian Piesik
    2021 Pełny tekst ENERGIES

    This article addresses current problems of risk analysis and probabilistic modelling for functional safety management in the life cycle of safety-related systems. Two main stages in the lifecycle of these systems are distinguished, namely the design and operation. The risk analysis and probabilistic modelling differ in these stages in view of available knowledge and data. Due to the complexity and uncertainty involved, both qualitative and quantitative information can be useful in risk analysis and probabilistic modelling. Some methodological aspects of the functional safety assessment are outlined that include mod-elling of dependent failures or cybersecurity and verifying the safety integrity level (SIL) under uncertainty. It is illustrated how the assumptions in the process of risk analysis and probabilistic modelling influence results obtained and, therefore, potentially the decisions taken in functional safety management. Programmable control and safety systems play an important role in mitigating and controlling risks in the operation of hazardous installa-tions. This paper presents ways to deal with safety hazards involving such systems to be considered in risk analysis and integrated functional safety and cybersecurity manage-ment.

  • Designing with Green and Blue – Climate Adaption Proposals for Lowland Areas of Gdańsk
    • Lucyna Nyka
    • Rui Simões
    • Pedro Ressano Garcia
    • Joanna Rayss
    2021

    The paper gives insight into issues explored within the framework of the SOS Climate Waterfront workshop that took place in Gdańsk in June 2019. The aim of the study was to propose solutions that will decrease the number of flooding events and span the gap between flood prevention strategies and the provision of other benefits such as ecological, urban, cultural and social. Historical cartography enquiries and research by the design method were used to develop design concepts. The main foundation for the design concept was built on the goal of providing more room for water, particularly for stormwater and rainwater. The second aim was to create blue-green connections that would span the amorphous territory and bring various benefits, including environmental, hydrological, and social. As research studies demonstrate, historical hydrographies can be effectively explored as guiding agents in urban climate adaptation schemes. Referring to past landscapes contributes not only to the protection but also to the exposition of cultural heritage and strengthening the relations between historical buildings and urban surroundings. It conduces to questioning the land-water dichotomy in favour of proposing their alternative and more fluid boundaries making territories less vulnerable to the threats brought by climate disasters.

  • Detecting Apples in the Wild: Potential for Harvest Quantity Estimation
    • Artur Janowski
    • Rafał Kaźmierczak
    • Cezary Kowalczyk
    • Jakub Szulwic
    2021 Pełny tekst Sustainability

    Knowing the exact number of fruits and trees helps farmers to make better decisions in their orchard production management. The current practice of crop estimation practice often involves manual counting of fruits (before harvesting), which is an extremely time-consuming and costly process. Additionally, this is not practicable for large orchards. Thanks to the changes that have taken place in recent years in the field of image analysis methods and computational performance, it is possible to create solutions for automatic fruit counting based on registered digital images. The pilot study aims to confirm the state of knowledge in the use of three methods (You Only Look Once—YOLO, Viola–Jones—a method based on the synergy of morphological operations of digital imagesand Hough transformation) of image recognition for apple detecting and counting. The study compared the results of three image analysis methods that can be used for counting apple fruits. They were validated, and their results allowed the recommendation of a method based on the YOLO algorithm for the proposed solution. It was based on the use of mass accessible devices (smartphones equipped with a camera with the required accuracy of image acquisition and accurate Global Navigation Satellite System (GNSS) positioning) for orchard owners to count growing apples. In our pilot study, three methods of counting apples were tested to create an automatic system for estimating apple yields in orchards. The test orchard is located at the University of Warmia and Mazury in Olsztyn. The tests were carried out on four trees located in different parts of the orchard. For the tests used, the dataset contained 1102 apple images and 3800 background images without fruits.

  • Detection and Direction-of-Arrival Estimation of Weak Spread Spectrum Signals Received with Antenna Array
    • Jarosław Magiera
    2021 Pełny tekst Electronics

    This paper presents a method for the joint detection and direction of arrival (DOA) estimation of low probability of detection (LPD) signals. The proposed approach is based on using the antenna array to receive spread-spectrum signals hidden below the noise floor. Array processing exploits the spatial correlation between phase-delayed copies of the signal and allows us to evaluate the parameter used to make the decision about the presence of LPD transmission. The DOA estimation is based on the covariance between signals received by sensors for the fixed geometry of the antenna array. Moreover, the paper provides a method for mitigating narrowband interferences prior to signal detection. The presented methods were verified through simulations which proved that the confident detection of a one-second transmission in an additive white Gaussian noise channel is possible even when the noise is 24 dB higher than the power of the received signal. The performance of DOA estimation is analyzed in a wide range of signal-to-noise and interference-to-noise ratios. It is found that the DOA may be estimated with an RMS error not exceeding 10 degrees, even if interference occupies 15% of the analyzed frequency band.

  • Detection and Model of Thermal Traces Left after Aggressive Behavior of Laboratory Rodents
    • Magdalena Mazur-Milecka
    • Jacek Rumiński
    • Wojciech Glac
    • Natalia Głowacka
    2021 Pełny tekst Applied Sciences-Basel

    Automation of complex social behavior analysis of experimental animals would allow for faster, more accurate and reliable research results in many biological, pharmacological, and medical fields. However, there are behaviors that are not only difficult to detect for the computer, but also for the human observer. Here, we present an analysis of the method for identifying aggressive behavior in thermal images by detecting traces of saliva left on the animals’ fur after a bite, nape attack, or grooming. We have checked the detection capabilities using simulations of social test conditions inspired by real observations and measurements. Detection of simulated traces different in size and temperature on single original frame revealed the dependence of the parameters of commonly used corner detectors (R score, ranking) on the parameters of the traces. We have also simulated temperature of saliva changes in time and proved that the detection time does not affect the correctness of the approximation of the observed process. Furthermore, tracking the dynamics of temperature changes of these traces allows to conclude about the exact moment of the aggressive action. In conclusion, the proposed algorithm together with thermal imaging provides additional data necessary to automate the analysis of social behavior in rodents.

  • DETECTION OF BREATHING AND HEART RATE USING AN ECG SIGNAL MEASURED WHILE BATHING IN THE BATHTUB
    • Kamil Osiński
    • Adam Bujnowski
    • Jerzy Wtorek
    • Oliwia Andrejko
    2021

    Nowadays a new area of interest is gaining importance - it is home biomedical examination. Intelligent home can be supported by set of devices for habitants observation. It can be particularly useful for elders or person with some health risks but living alone. One of critical locations within the house is bathroom. One of utilities in the bathroom is a bathtub which is sometimes preferred over shower. There are reports of problems during bath such as mobility problem when leaving bathtub or even sudden death cases.

  • Detection of Lexical Stress Errors in Non-Native (L2) English with Data Augmentation and Attention
    • Daniel Korzekwa
    • Roberto Barra-Chicote
    • Szymon Zaporowski
    • Grzegorz Beringer
    • Jaime Lorenzo-trueba
    • Alicja Serafinowicz
    • Jasha Droppo
    • Thomas Drugman
    • Bożena Kostek
    2021 Pełny tekst

    This paper describes two novel complementary techniques that improve the detection of lexical stress errors in non-native (L2) English speech: attention-based feature extraction and data augmentation based on Neural Text-To-Speech (TTS). In a classical approach, audio features are usually extracted from fixed regions of speech such as the syllable nucleus. We propose an attention-based deep learning model that automatically de rives optimal syllable-level representation from frame-level and phoneme-level audio features. Training this model is challenging because of the limited amount of incorrect stress patterns. To solve this problem, we propose to augment the training set with incorrectly stressed words generated with Neural TTS. Combining both techniques achieves 94.8% precision and 49.2% recall for the detection of incorrectly stressed words in L2 English speech of Slavic and Baltic speakers.

  • Detection of petroleum products using optical coherence tomography
    • Aleksandra Kamińska
    • Jerzy Pluciński
    2021 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    In this work, we present a novel method developed for the analysis of the properties of thin layers for detecting petroleum products on a water surface using a commercially available optical coherence tomography (OCT) system. The spectral density analysis of the signal from a spectroscopic OCT (S-OCT) enables us to perform the precision calculation of the thin layer thickness and other properties like homogeneity, and dispersion, even if layer thickness is smaller than the coherence length of light from the used broadband light source. Mathematical modeling has been confirmed by measurements. The experiment with thin oil films on the surface of the water was conducted. The obtained results indicate that it is possible to measure the thickness of the petroleum product layers on the surface of the water smaller than 1 μm with 10 nm resolution.

  • Deterioration and Protection of Concrete Elements Embedded in Contaminated Soil: A Review
    • Ginneth Patricia Millán Ramírez
    • Hubert Byliński
    • Maciej Niedostatkiewicz
    2021 Pełny tekst Materials

    Coating materials are considered one of the most antique materials of human civilization; they have been used for decoration and the protection of surfaces for millennia. Concrete structures—due to their permanent exposure to different types of environments and contaminants—require the use of coatings that contribute to its preservation by reducing the corrosion of its components (steel and aggregates). This article intends to introduce the principal causes of concrete deterioration and the coating materials used to protect concrete structures, including a summary of the coating types, their advantages and disadvantages, and the latest developments and applications. Furthermore, this paper also assesses brief information about the potential challenges in the production of eco-friendly coating materials.

  • Determinants of COVID-19 Impact on the Private Sector: A Multi-Country Analysis Based on Survey Data
    • Magdalena Olczyk
    • Marta Kuc-Czarnecka
    2021 Pełny tekst ENERGIES

    Our paper aims to investigate the impact of COVID‐19 on private sector companies in terms of sales, production, finance and employment. We check whether the country and industry in which companies operate, government financial support and loan access matter to the behaviour and performances of companies during the pandemic. We use a microdata set from a worldwide survey of more than 15,729 companies conducted between April and September 2020 by the World Bank. Logistic regression is used to assess which factors increase the likelihood of businesses suffering due to the COVID‐19 pandemic. Our results show that COVID‐19 negatively impacts the performance of companies in almost all countries analysed, but a stronger effect is observed among firms from developing countries. The pandemic is more harmful to firms providing services than those representing the manufacturing sector. Due to the pandemic, firms suffer mainly in sales and liquidity decrease rather than employment reduction. The increase in the number of temporary workers is an important factor that significantly reduces the probability of sales, exports or supply decline. The analysis results indicate policy tools supporting enterprises during the pandemic, such as increasing the flexibility of the labour market or directing aid to developing countries.

  • Determinants of the primary stability of cementless acetabular cup implants: A 3D finite element study
    • Katharina Immel
    • Vu–Hieu Nguyen
    • Arnaud Dubory
    • Charles-Henri Flouzat-Lachaniette
    • Roger Sauer
    • Guillaume Haiat
    2021 Pełny tekst COMPUTERS IN BIOLOGY AND MEDICINE

    Primary stability of cementless implants is crucial for the surgical success and long–term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press–fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference fit IF and the sliding friction coefficient of the bone–implant interface μ on the primary stability of an AC implant. For each parameter combination, the insertion of the AC implant into the hip cavity and consequent pull–out are simulated with a 3D finite element model of a human hemi–pelvis. The primary stability is assessed by determining the polar gap and the maximum pull–out force. The polar gap increases along with all considered parameters. The pull–out force shows a continuous increase with Ec and Et and a non-linear variation as a function of μ and IF is obtained. For μ > 0.6 and IF > 1.4mm the primary stability decreases, and a combination of smaller μ and IF lead to a better fixation. Based on the patient's bone stiffness, optimal combinations of μ and IF can be identified. The results are in good qualitative agreement with previous studies and provide a better understanding of the determinants of the AC implant primary stability. They suggest a guideline for the optimal choice of implant surface roughness and IF based on the patient's bone quality.

  • DETERMINATION OF THE AERODYNAMIC DRAG OF PNEUMATIC LIFE RAFTS AS A FACTOR FOR INCREASING THE RELIABILITY OF RESCUE OPERATIONS
    • Edyta Ksiązkiewicz
    • Jacek Jachowski
    • Izabela Szwoch
    2021 Pełny tekst Polish Maritime Research

    Ensuring the safety of ship crews at sea is of the utmost importance. Life rafts are one of the basic components of any seagoing vessel and ensuring their stability is an important component of maritime research. This study concerns the determination of the aerodynamic drag coefficients of pneumatic life rafts in a full range of wind speed and directions. The drag coefficients are based on full-scale experimental studies and numerical calculations (computational fluid dynamics) carried out with Flow-3D software. Two types of life rafts are analysed in the numerical simulations, namely, a non-deformed raft and a raft deformed under the influence of wind pressure at a given flow velocity. The shape of the deformed pneumatic life raft is recreated on the basis of photographic documentation from experimental studies. The results of the numerical calculations are verified on the basis of full-scale flow experiments carried out at the Low Speed Wind Tunnel T-3 Laboratory at the Institute of Aviation in Warsaw. This study shows that there is a dependence of aerodynamic drag on the degree of deformation of the above-water part of the life raft, as well as the angle of the raft setting to the wind. In real water conditions, this angle depends mainly on the anchor point of the drift anchor and therefore should be considered at the design stage, which will directly reduce the wind leeway of the raft.

  • Determination of the refractive index and wavelength‐dependent optical properties of few‐layer CrCl3 within the Fresnel formalism
    • Shafaq Kazim
    • Roberto Gunnella
    • Marco Zannotti
    • Rita Giovannetti
    • Tomasz Klimczuk
    • Luca Ottaviano
    2021 Pełny tekst JOURNAL OF MICROSCOPY

    Based on previous reports on the optical microscopy contrast of mechanically exfoliated few layer CrCl3 transferred on 285 nmand 270 nmSiO2 on Si(100), we focus on the experimental determination of an effective mean complex refractive index via a fitting analysis based on the Fresnel equations formalism. Accordingly, the layer and wavelength-dependent absorbance and reflectance are calculated. Layer and wavelength-dependent optical contrast curves are then evaluated demonstrating that the contrast is significantly high only around welldefined wavelength bands. This is validated a posteriori, by experimental UVVis absorbance data. The present study aims to show the way towards the most reliable determination of thickness of the 2D material flakes during exfoliation.

  • Determination of the Theoretical and Actual Working Volume of a Hydraulic Motor—Part II (The Method Based on the Characteristics of Effective Absorbency of the Motor)
    • Paweł Śliwiński
    2021 Pełny tekst ENERGIES

    : In this article, the second method of determination of the theoretical and actual working volume of a hydraulic motor is described. The proposed new method is based on the characteristics of effective absorbency of the motor. The effective absorbency has been defined as the ratio of flow rate in a motor to the rotational speed of the motor’s shaft. It has been shown that the effective absorbency is a nonlinear function of the rotational speed and nonlinear function of the pressure drop in the motor’s working chambers. Furthermore, it has been proven that the actual working volume of a motor is a function of a third degree of pressure drop in the motor’s working chamber. The actual working volume should be taken to assess the mechanical and volumetric energy losses in the motor. Furthermore, the influence of the flowmeter location in the measurement system and the compressibility of liquid on the result of the theoretical and actual working volume calculation was also taken into account and is described in this article. The differences in the assessment of the volumetric efficiency assuming the theoretical and actual working volume was also shown.

  • Determining horizontal curvature of railway track axis in mobile satellite measurements
    • Władysław Koc
    • Andrzej Wilk
    • Cezary Specht
    • Krzysztof Karwowski
    • Jacek Skibicki
    • Krzysztof Czaplewski
    • Sławomir Judek
    • Piotr Chrostowski
    • Jacek Szmagliński
    • Paweł Dąbrowski
    • Mariusz Specht
    • Sławomir Grulkowski
    • Roksana Licow
    2021 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences

    The article discusses the applicability of a novel method to determine horizontal curvature of the railway track axis based on results of mobile satellite measurements. The method is based on inclination angle changes of a moving chord in the Cartesian coordinate system. In the presented case, the variant referred to as the method of two virtual chords is applied which consists in manoeuvring with only one GNSS (Global Navigation Satellite System) receiver. The assumptions of the novel method are formulated, and the assessment of its application in the performed campaign of mobile satellite measurements is given. The shape of the measured railway axis is shown in the national spatial reference system PL-2000, and the speed of the measuring trolley during the measurement is calculated based on the recorded coordinates. It has been observed that over the test section, the curvature ordinates differ from the expected waveform, which can be caused by disturbances of the measuring trolley trajectory. However, this problem can easily be overcome by filtering the measured track axis ordinates to obtain the correct shape – this refers to all track segments: straight sections, circular arcs, and transition curves. The virtual chord method can also be the basis for assessing the quality of the recorded satellite signal. The performed analysis has shown high accuracy of the measuring process.

  • Determining the Seasonal Variability of the Territorial Sea Baseline in Poland (2018–2020) Using Integrated USV/GNSS/SBES Measurements
    • Mariusz Specht
    • Cezary Specht
    • Andrzej Stateczny
    • Łukasz Marchel
    • Oktawia Lewicka
    • Monika Paliszewska-Mojsiuk
    • Marta Wiśniewska
    2021 Pełny tekst ENERGIES

    The Territorial Sea Baseline (TSB) allows coastal states to define the maritime boundaries, such as: contiguous zone, continental shelf, exclusive economic zone and territorial sea. Their delimitations determine what rights (jurisdiction and sovereignty) a given coastal state is entitled to. For many years, the problem of delimiting baseline was considered in two aspects: legal (lack of clear-cut regulations and different interpretations) and measurement (lack of research tools for precise and reliable depth measurement in ultra-shallow waters). This paper aimed to define the seasonal variability of the TSB in 2018–2020. The survey was conducted in three representative waterbodies of the Republic of Poland: open sea, river mouth and exit from a large port, differing between each other in seabed shape. Baseline measurements were carried out with Unmanned Surface Vehicles (USV), equipped with Global Navigation Satellite System (GNSS) geodetic receivers and miniature Single Beam Echo Sounders (SBES). The survey has shown that the smallest seasonal variability of TSB (1.86–3.00 m) was confirmed for the waterbody located near the Vistula ´Smiała River mouth, which features steep shores. On the other hand, the greatest variability in the baseline (5.73–8.37 m) as observed in the waterbody adjacent to the public beach in Gdynia. Factors conditioning considerable changes in TSB determination were: periodically performed land reclamation works in the area and the fact that the depth of the waterbody increases slowly when moving away from the coastline.

  • Detoxification of the tricyclic antidepressant opipramol and its analog – IS-noh by UGT enzymes before and after activation by phase I enzymes in rat liver microsomes
    • Anna Mieszkowska
    • Koleta Hemine
    • Anna Skwierawska
    • Ewa Augustin
    • Zofia Mazerska
    2021 Pełny tekst CHEMICAL PAPERS

    The present studies were carried out to evaluate the simultaneous one-pot metabolism of opipramol (IS-opi) and analog (IS-noh) by phase I and phase II enzymes present in rat liver microsomes (RLM) as an alternative to separate testing with recombinant enzymes. This approach allows for more time-saving and cost-effective screening of the metabolism of newly discovered drugs. We also considered that the lack of results for phase II, including UGT, often creates problems in correct selection of valuable compounds. Moreover, microsomes data set is richer in the contest and provides medical scientist to determine also the susceptibility of drugs to undergo phase I and then phase II. In the present work, we have shown that IS-noh was metabolized in vitro by phase I enzymes to the oxidation product, which was next transformed with UGTs to glucuronide. The results showed also that the previously known oxidation product of opipramol was changed to previously no reported glucuronidation product by UDP-glucuronosyltransferases. In addition, unlike IS-noh, opipramol did not prove to be the substrate for UGTs. Therefore, tricyclic antidepressants depending on the structure can trigger a different response after contact with UGT enzymes. Some will metabolize directly with UGTs, others only after activation by phase I enzymes.

  • Developing Methods for Building Intelligent Systems of Information Resources Processing Using an Ontological Approach
    • Vasyl Lytvyn
    • Victoria Vysotska
    • Myroslava Bublyk
    • Piotr Grudowski
    • Yurii Matseliukh
    • Roman Nanivskyi
    2021 Advances in Intelligent Systems and Computing

    The problem of developing methods of information resource processing is investigated. A formal procedure description of processing text content is developed. A new ontological approach to the implementation of business processes is proposed. Consider that the aim of our work is to develop methods and tools for building intelligent systems of information resource processing, the core of knowledge bases of which are ontology’s, and improve the efficiency of such systems by adapting ontology to the specifics of the subject area. The proposed approach is aimed at solving such problems: Analysis of the specifics and methods of building intelligent systems of information resource processing by classifying them according to the principle and space of functioning, which will distinguish the types of such systems depending on the mathematical support of their functioning; Development of mathematical models and methods of functioning of various classes of intelligent systems of information resource processing, the core of knowledge bases which is ontology, to study the effectiveness of such systems; Development of methods and algorithms of ontology adaptation to the specific tasks of the subject area in order to improve the efficiency of intelligent systems of information resources processing within this subject area; Definition of characteristics of quality of intellectual systems of processing of information resources and criteria of optimization of ontology’s as a part of their knowledge bases for increase of indicators of efficiency of functioning of such systems. The methods and tools will be used to build modern applied intelligent systems of information resource processing, the core of knowledge bases which are ontology’s, in such subject areas as management and maintenance of information resources on the Internet, during the construction of systems on-line and off-line content implementation, cloud storage, cloud computing, in the military and legal sphere. The expansion of the areas of application of the designed and developed intelligent systems of information resource processing based on ontology’s will help to overcome social, organizational, methodological and psychological barriers that arise as a reaction to the introduction of innovative approaches to the conduct of activities in the relevant sectors of the economy and regulatory spheres of functioning.

  • Development and validation of a method for the simultaneous analysis of fatty acid ethyl esters, ethyl sulfate and ethyl glucuronide in neonatal meconium: application in two cases of alcohol consumption during pregnancy
    • Mateusz Woźniak
    • Laura Banaszkiewicz
    • Justyna Aszyk
    • Marek Wiergowski
    • Iwona Jańczewska
    • Jolanta Wierzba
    • Agata Kot-Wasik
    • Marek Biziuk
    2021 Pełny tekst ANALYTICAL AND BIOANALYTICAL CHEMISTRY

    Alcohol consumption during pregnancy constitutes one of the leading preventable causes of birth defects and neurodevelopmental disorders in the exposed children. Fatty acid ethyl esters (FAEEs), ethyl glucuronide (EtG) and ethyl sulfate (EtS) have been studied as potential biomarkers of alcohol consumption. However, most analytical approaches proposed for their analysis in meconium samples consist of separated extraction procedures requiring the use of two meconium aliquots, which is costly in terms of both time and materials. Therefore, the aim of this study was to develop and validate a method for the simultaneous extraction of 9 FAEEs, EtG and EtS from one meconium aliquot. The sample was homogenized using methanol, and then FAEEs were extracted with hexane while EtG and EtS were isolated using acetonitrile. Then, extracts were applied to solid-phase extraction columns and analysed by gas chromatography mass spectrometry (FAEEs) and liquid chromatography tandem mass spectrometry (EtG and EtS). Calibration curves were linear with r values greater than 0.99. The LODs ranged from 0.8 to 7.5 ng/g for FAEEs and were 0.2 ng/g and 0.8 ng/g for EtS and EtG, respectively. LOQs ranged from 5 to 25 ng/g for FAEEs and were 1 ng/g and 2.5 ng/g for EtS and EtG, respectively. Accuracies and precisions were between 93.8 and 107% and between 3.5 and 9.7%, respectively. The recovery values ranged from 89.1 to 109%. The method proved to be sensitive, specific, simple and fast and allowed for the reduction of the amount of organic solvent used for extraction compared to other published data while higher recoveries were obtained. The method was used for analysis meconium samples in two cases of mothers who were consuming alcohol during pregnancy.

  • Development, characterization and evaluation of composite adsorbent for the adsorption of crystal violet from aqueous solution: Isotherm, kinetics, and thermodynamic studies
    • Mohamed Sulyman
    • Justyna Kucińska-Lipka
    • Maciej Sienkiewicz
    • Andrzej Gierak
    2021 Pełny tekst Arabian Journal of Chemistry

    The purpose of this work focuses on the production and investigations of a new composite material as alternative low-cost adsorbent for the removal of crystal violet (CV) dye from waste solution. The production method was performed by in-situ thermal activation technology via extrusion process of polymer wastes containing tire rubber (50 wt%) and polyurethane foam (50 wt%) using single-screw extruder under processing temperature of 180 °C and shearing rate 100 rpm. The physico-chemical properties of the materials obtained were examined such as bulk density, zero surface charge (pHpzc), Brunauer-Emmett-Teller (BET) surface area, as well as samples tested by infrared absorption spectroscopy (FT-IR), scanning electron microscopy (SEM). X-ray fluorescence spectroscopy (WD-XRF). Thermogravimetric analysis (TGA). These techniques were additionally applied to the full characteristics of the composite materials obtained. The impacts of solution pH (3.0–9.0), adsorbent dosage (0.1–1.0 g) and initial adsorbate concentration (in range 10 –90 mg/l) on adsorption capacity of the investigated adsorbent were studied. From our investigation we found that adsorption equilibrium was achieved within 200 min. The maximum monolayer adsorption capacity (qmax) for our composite adsorbent were obtained from the Langmuir equation and equaled 20.92 mg/g. Mathematical analysis has shown that the pseudo second kinetic model of the order describes the kinetics of the adsorption process well.

  • Development of a tropical disease diagnosis system using artificial neural network and GIS
    • Paweł Cieszko
    • Marcin Kulawiak
    • Natalia Kulawiak
    • Katarzyna Sikorska
    • Aleksander Stojanowski
    • Paweł Goławski
    2021

    Expert systems for diagnosis of tropical diseases have been developed and implemented for over a decade with varying degrees of success. While the recent introduction of artificial neural networks has helped to improve the diagnosis accuracy of such systems, this aspect is still negatively affected by the number of supported diseases. A large number of supported diseases usually corresponds to a high number of overlapping symptoms, which results in a considerable drop in diagnosis accuracy. This is particularly important when diagnosing patients returning from holiday or business trips which took them through a number of different tropical regions. The paper presents a system dedicated to diagnosis of patients returning from various tropical countries. The system integrates an artificial neural network with a Geographic Information System (GIS) in order to enhance the diagnostic process. As a result, the system provides several layers of diagnosis support, depending on the types and number of provided patient characteristics. The system has been developed in cooperation with the University Center of Maritime and Tropical Medicine located in the city of Gdynia in northern Poland and applied to diagnosis of patients with malaria, dengue and stechiostomasis with promising results.

  • Development of Gas Sensor Array for Methane Reforming Process Monitoring
    • Dominik Dobrzyniewski
    • Bartosz Szulczyński
    • Tomasz Dymerski
    • Jacek Gębicki
    2021 Pełny tekst SENSORS

    The article presents a new method of monitoring and assessing the course of the dry methane reforming process with the use of a gas sensor array. Nine commercially available TGS chemical gas sensors were used to construct the array (seven metal oxide sensors and two electrochemical ones). Principal Component Regression (PCR) was used as a calibration method. The developed PCR models were used to determine the quantitative parameters of the methane reforming process: Inlet Molar Ratio (IMR) in the range 0.6–1.5, Outlet Molar Ratio (OMR) in the range 0.6–1.0, and Methane Conversion Level (MCL) in the range 80–95%. The tests were performed on model gas mixtures. The mean error in determining the IMR is 0.096 for the range of molar ratios 0.6–1.5. However, in the case of the process range (0.9–1.1), this error is 0.065, which is about 6.5% of the measured value. For the OMR, an average error of 0.008 was obtained (which gives about 0.8% of the measured value), while for the MCL, the average error was 0.8%. Obtained results are very promising. They show that the use of an array of non-selective chemical sensors together with an appropriately selected mathematical model can be used in the monitoring of commonly used industrial processes.

  • Development of globalization in culture on the example of Europe
    • Monika Hadaś-dyduch
    • Sebastian Wilczewski
    2021

    This article attempts to reflect on the consequences of cultural globalization i.e. the opporturnities and threats that exist it brings with it for existing local cultures. As we know, The processes of globalization contribute to the emergence of any, often contradictory phenomena in the field of culture which influence the existing local cultural systems in various ways. It is assumed that the most important consequence of cultural globalization is the increased contact of different cultures, thanks to which certain cultural elements are mixed disseminated and sometimes rnade similar. The study was based on the countries belonging to Europe. The aim of the study is to identify couritries most similar to Poland in the development of cultural globalization. The study used an algorithm based on the wavelet transform and DTW. The DTW algorithm was used in the study because it is extremely effective in measuring the similarity of signials in the time domain. It minimizes the effects of shifting and distorting signals through "flexible" transformation of the time signal which allows you to find similar shapes with different phases.

  • Development of Microstructured Carbon Coatings by Substrate-Catalytic CVD
    • Mattia Pierpaoli
    • Mirosław Sawczak
    • Anna Dettlaff
    2021 Pełny tekst Coatings

    Carbon nanostructured films were synthesized by chemical vapor deposition (CVD) on H18 stainless steel (AISI 440C) sheets with an H2/CH4/N2 gas mixture at various substrate temperatures. During the synthesis, the iron and chromium oxide layer was formed between the steel and carbonaceous layer. The carbon films exhibited wall-like and spherical morphologies and structures, as characterized by scanning electron microscopy and Raman spectroscopy. It was found that the synthesis temperature affects the microsphere density and, therefore, also in the electrochemical behavior. The electrochemical behavior of nanostructured carbon coatings strongly depends on the CVD deposition conditions. The best corrosion resistance (Rp = 11.8 MΩ·cm2, Icorr = 4.4 nA·cm−2) exhibits a nanostructured carbon sample with a moderate amount of sp2-C-rich carbon microspheres CμSs synthesized at 700 °C. The corrosion resistance of the nanostructured carbon coating is better than raw stainless steel.

  • Development of Strategies for AOB and NOB Competition Supported by Mathematical Modeling in Terms of Successful Deammonification Implementation for Energy-Efficient WWTPs
    • Mehdi Sharifshourjeh
    • Przemysław Kowal
    • Lu Xi
    • Li Xie
    • Jakub Drewnowski
    2021 Pełny tekst Processes

    Novel technologies such as partial nitritation (PN) and partial denitritation (PDN) could be combined with the anammox-based process in order to alleviate energy input. The former combination, also noted as deammonification, has been intensively studied in a frame of lab and full-scale wastewater treatment in order to optimize operational costs and process efficiency. For the deammonification process, key functional microbes include ammonia-oxidizing bacteria (AOB) and anaerobic ammonia oxidation bacteria (AnAOB), which coexisting and interact with heterotrophs and nitrite oxidizing bacteria (NOB). The aim of the presented review was to summarize current knowledge about deammonification process principles, related to microbial interactions responsible for the process maintenance under varying operational conditions. Particular attention was paid to the factors influencing the targeted selection of AOB/AnAOB over the NOB and application of the mathematical modeling as a powerful tool enabling accelerated process optimization and characterization. Another reviewed aspect was the potential energetic and resources savings connected with deammonification application in relation to the technologies based on the conventional nitrification/denitrification processes

  • Developments in Miniaturization of Gas Chromatography
    • Waldemar Wardencki
    • Zygfryd Witkiewicz
    2021

    .

  • DFT study of low-energy electron interaction with pyridine, pyrazine and their halo derivatives
    • Natalia Tańska
    2021 Pełny tekst EUROPEAN PHYSICAL JOURNAL D

    In this work, the density functional theory with B3LYP hybrid functional was employed to calculate quantities useful for estimating the behavior of pyridine, pyrazine and their derivatives monosubstituted with Cl or Br atom, when exposed to low-energy electron impact. Vertical electron affinities obtained in several Pople basis sets and in aug-cc-pVTZ basis set are reported. Although some of the investigated molecules do not form stable anions, the results are in a satisfactory agreement with the available, albeit sparse experimental data, if the diffuse functions are included in calculations. It was found that the 6-31+G* basis is sufficient and its further enlargement does not significantly change the results. At this level of theory, potential energy curves, supported by enthalpies of dissociation to the neutral and anion fragment, were also determined for the description of the dissociative electron attachment. According to B3LYP, the potential energy curves of the halogen bond are almost repulsive in halopyridines, whereas halopyrazine anions require small activation energy for dissociation. Vertical electron affinities, enthalpies and equilibrium C-X distances (X=H, Cl, Br) were also calculated using Møller-Plesset second-order perturbation theory.

  • Diagnostic Accuracy of Liquid Biopsy in Endometrial Cancer
    • Marta Łukasiewicz
    • Krzysztof Pastuszak
    • Sylwia Łapińska-Szumczyk
    • Robert Różański
    • Sjors In ’t Veld
    • Michał Bieńkowski
    • Tomasz Stokowy
    • Magdalena Ratajska
    • Myron G Best
    • Thomas Würdinger
    • Anna Żaczek
    • Anna Supernat
    • Jacek Jassem
    2021 Pełny tekst Cancers

    Background: Liquid biopsy is a minimally invasive collection of a patient body fluid sample. In oncology, they offer several advantages compared to traditional tissue biopsies. However, the potential of this method in endometrial cancer (EC) remains poorly explored. We studied the utility of tumor educated platelets (TEPs) and circulating tumor DNA (ctDNA) for preoperative EC diagnosis, including histology determination. Methods: TEPs from 295 subjects (53 EC patients, 38 patients with benign gynecologic conditions, and 204 healthy women) were RNA-sequenced. DNA sequencing data were obtained for 519 primary tumor tissues and 16 plasma samples. Artificial intelligence was applied to sample classification. Results: Platelet-dedicated classifier yielded AUC of 97.5% in the test set when discriminating between healthy subjects and cancer patients. However, the discrimination between endometrial cancer and benign gynecologic conditions was more challenging, with AUC of 84.1%. ctDNA-dedicated classifier discriminated primary tumor tissue samples with AUC of 96% and ctDNA blood samples with AUC of 69.8%. Conclusions: Liquid biopsies show potential in EC diagnosis. Both TEPs and ctDNA profiles coupled with artificial intelligence constitute a source of useful information. Further work involving more cases is warranted.

  • DIAGNOSTIC INFORMATION ANALYSIS OF QUICKLY CHANGING TEMPERATURE OF EXHAUST GAS FROM MARINE DIESEL ENGINE PART I SINGLE FACTOR ANALYSIS
    • Patrycja Puzdrowska
    2021 Pełny tekst Polish Maritime Research

    In this paper, attention was paid to the problem of low controllability of marine medium- and high-speed engines during operation, which significantly limits the parametric diagnosis. The measurement of quickly changing temperature of engine exhaust gas was proposed, the courses of which can be a source of diagnostic information. The F statistic of the Fisher-Snedecor distribution was chosen as a statistical tool. Laboratory tests were carried out on the bench of a Farymann Diesel engine. The tests consisted of introducing the real changes in the constructional structure of the considered functional systems of the engine. Three changed parameters for the structure were reviewed: the active cross-sectional area of the inlet air channel, injector opening pressure and compression ratio. Based on the recorded plots of the quick-changing temperatures of the exhaust gases, three diagnostic measures were defined and subjected to statistical tests. The following data were averaged over one cycle for a 4-stroke piston engine operation, (1) the peak to peak value of the exhaust gas temperature, (2) the specific enthalpy of the exhaust gas, and (3) the rate of increase and decrease in the values for the quick-changing exhaust gas temperature. In this paper will present results of the first stage of the elimination study: the one-factor statistical analysis (randomised complete plan). The next part will present the results of the second stage of studies: two-factor analysis (block randomised plan), where the significance of the effect of changing the values of the structure parameters on the diagnostic measures was analysed in the background of a variable engine load.

  • Diamond Nanofilm Normalizes Proliferation and Metabolism in Liver Cancer Cells
    • Malwina Sosnowska
    • Marta Kutwin
    • Barbara Strojny
    • Mateusz Wierzbicki
    • Dominik Cysewski
    • Jarosław Szczepaniak
    • Mateusz Ficek
    • Piotr Koczoń
    • Sławomir Jaworski
    • André Chwalibog
    • Ewa Sawosz
    2021 Pełny tekst Nanotechnology Science and Applications

    Purpose: Surgical resection of hepatocellular carcinoma can be associated with recurrence resulting from the degeneration of residual volume of the liver. The objective was to assess the possibility of using a biocompatible nanofilm, made of a colloid of diamond nanoparticles (nfND), to fill the side after tumour resection and optimize its contact with proliferating liver cells, minimizing their cancerous transformation. Methods: HepG2 and C3A liver cancer cells and HS-5 non-cancer cells were used. An aqueous colloid of diamond nanoparticles, which covered the cell culture plate, was used to create the nanofilm. The roughness of the resulting nanofilm was measured by atomic force microscopy. Mitochondrial activity and cell proliferation were measured by XTT and BrdU assays. Cell morphology and a scratch test were used to evaluate the invasiveness of cells. Flow cytometry determined the number of cells within the cell cycle. Protein expression in was measured by mass spectrometry. Results: The nfND created a surface with increased roughness and exposed oxygen groups compared with a standard plate. All cell lines were prone to settling on the nanofilm, but cancer cells formed more relaxed clusters. The surface compatibility was dependent on the cell type and decreased in the order C3A >HepG2 >HS-5. The invasion was reduced in cancer lines with the greatest effect on the C3A line, reducing proliferation and increasing the G2/M cell population. Among the proteins with altered expression, membrane and nuclear proteins dominated. Conclusion: In vitro studies demonstrated the antiproliferative properties of nfND against C3A liver cancer cells. At the same time, the need to personalize potential therapy was indicated due to the differential protein synthetic responses in C3A vs HepG2 cells. We documented that nfND is a source of signals capable of normalizing the expression of many intracellular proteins involved in the transformation to non-cancerous cells.

  • Diaryl Sulfide Derivatives as Potential Iron Corrosion Inhibitors: A Computational Study
    • Morad El-Hendawy
    • Asmaa Kamel
    • Mohamed Mahmoud
    • Rabah Boukherroub
    • Jacek Ryl
    • Mohammed Amin
    2021 Pełny tekst MOLECULES

    The present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the reference compound to evaluate the efficiency of the remainder. In this respect, two structural factors were examined, namely, (i) the effect of replacement of the S-atom of diaryl sulfide by SO or SO2 group, (ii) the effect of the introduction of an electron-withdrawing or an electron-donating group in the aryl moiety. Two computational chemical approaches were used to achieve the objectives: the density functional theory (DFT) and the Monto Carlo (MC) simulation. First, B3LYP/6-311+G(d,p) model chemistry was employed to calculate quantum chemical descriptors of the studied molecules and their geometric and electronic structures. Additionally, the mode of adsorption of the tested molecules was investigated using MC simulation. In general, the adsorption process was favorable for molecules with a lower dipole moment. Based on the adsorption energy results, five diaryl sulfide derivatives are expected to act as better corrosion inhibitors than dapsone.

  • Dibutyl phthalate disrupts conserved circadian rhythm in Drosophila and human cells
    • Wen Liu
    • Hao Cao
    • Sifang Liao
    • Błażej Kudłak
    • Michael Williams
    • Helgi B. Schiöth
    2021 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT

    People are constantly exposed to phthalates, due to their common use in the production of plastics, pharmaceuticals, cosmetics and skin care products. The ability of phthalates to disrupt endocrine signaling, leading to developmental, reproductive and metabolic defects, has been studied, yet how phthalates interfere with these biological functions is still unclear. To uncover DBP interacting molecular pathways, we raised Drosophila melanogaster on food containing dibutyl phthalate (DBP) at various concentrations. Whole transcriptome analysis of adult Drosophila reveals that DBP exposure throughout development disrupts the expression of genes central to circadian rhythm regulation, including increased expression of vrille (vri, human NFIL3), timeless (tim, human TIMELESS) and period (per, human PER3), with decreased expression of Pigment-dispersing factor (Pdf). DBP exposure also alters the expression of the evolutionarily conserved nuclear receptor Hormone receptor-like in 38 (Hr38, human NR4A2), which is known to regulate Pdf expression. Furthermore, behavioral assays determined that exposing Drosophila to DBP throughout development modifies the circadian rhythm of adults. Although DBP inhibits the expression of signaling systems regulating vision, including Rh5 and Rh6, two light-sensing G-protein coupled receptors involved in the daily resetting of circadian rhythm, it does not influence eye development. Circadian rhythm genes are well conserved from flies to humans; therefore, we tested the effect of DBP exposure on human breast cells (MCF10A) and demonstrate that, similar to the fruit fly model, this exposure disrupts circadian rhythm (BMAL1 expression) at doses that promote the proliferation and migration ability of MCF10A cells. Our results are the first to provide comprehensive evidence that DBP interferes with circadian rhythm in both adult Drosophila and human cells, which may help to explain the broad physiological action of phthalates.

  • Difference in Perceived Speech Signal Quality Assessment Among Monolingual and Bilingual Teenage Students
    • Przemysław Falkowski-Gilski
    2021

    The user perceived quality is a mixture of factors, including the background of an individual. The process of auditory perception is discussed in a wide variety of fields, ranging from engineering to medicine. Many studies examine the difference between musicians and non-musicians. Since musical training develops musical hearing and other various auditory capabilities, similar enhancements should be observable in case of bilingual people. This paper examines the difference in perceived speech signal quality between students from monolingual and bilingual classes. The subjective study was carried out on a group of 30 people, with 15 individuals in each class, aged 16–18 years old, considering three languages: English, German, and Polish. Results of this study may aid researchers as well as professionals active in the field of auditory perception, hearing loss related with ageing, and of course evaluation of networks and services.

  • Different design aspects of an Organic Rankine Cycle turbine for electricity production using a geothermal binary power plant
    • Paweł Ziółkowski
    • Rafał Hyrzyński
    • Marcin Daniel Lemański
    • Bartosz Kraszewski
    • Sebastian Bykuć
    • Stanisław Głuch
    • Anna Sowiżdżał
    • Leszek Pająk
    • Anna Wachowicz-Pyzik
    • Janusz Badur
    2021 Pełny tekst ENERGY CONVERSION AND MANAGEMENT

    In recent years, pressure has been growing to increase the share of renewable energy sources in electricity generation, which may offer opportunities for the development of geothermal energy in regions that have been so far considered unprofitable in this respect. One such country currently undergoing an energy transition is Poland in which low-temperature geothermal resources are currently used for district heating and recreation purposes. Nevertheless, research on the possibilities of using geothermal energy for electricity production is ongoing. The objective of this paper was to perform a comprehensive analysis of a binary power plant construction in relation to low-temperature petro-geothermal resources. The potential binary power plant is located in the area characterized by temperature of 120 ◦C at depths of 5000 m. About half of Poland’s area, especially the regions of western and central Poland, has these characteristics. It was assumed that brine at volume flow rate of 400 m3/h is a heat source for the Organic Rankine Cycle with isobutane as a working medium. The thermal efficiency based on the First Law of Thermodynamics and the power output were estimated at 10.5% and 1.79 MWe, respectively. In addition, the thermal efficiency based on the Second Law of Thermodynamics was calculated at 29.0%. For the calculated cycle parameters, a preliminary design of a two-stage axial turbine was constructed. All results were compared to the other binary power plants and they confirm that establishing the binary power plant in Poland would be thermodynamically justified. The main novelty of the present work is the combination of three issues, namely the selection of the low- temperature heat source, the design and analysis of the cycle together with a turbine adapted to these conditions.

  • Differentia specifica wystawa indywidualna
    • Dominika Krechowicz
    2021

    Differentia specifica Wystawa indywidualna (wspólnie z Krzysztofem Gliszczyńskim) zrealizowana w Galerii Feininger, w Trzebiatowskim Ośrodku Kultury w Trzebiatowie. Na wystawie zaprezentowane zostały prace malarskie oraz obiekty, które zawierają w sobie pamięć ciała, gestu. Obraz ujawnia pamięć artysty, jego wyobraźnię, która jest zbiorem rzeczy widzianych i zapamiętanych. Podświadomość wykorzystuje je w procesie pracy, dekonstruuje i zestawia na nowo. Tytuł wystawy "Differentia specifica" odnosi się do różnic charakterystycznych dla dwóch odmiennych postaw twórczych. (Differentia specifica - cecha istotna, odróżniająca jakiś gatunek od innych gatunków tego samego rodzaju).

  • Digital Innovations and Smart Solutions for Society And Economy: Pros and Cons
    • Marcin Sikorski
    2021 Pełny tekst Foundations of Management

    Recent developments in artificial intelligence (AI) may involve significant potential threats to personal data privacy, national security, and social and economic stability. AI-based solutions are often promoted as “intelligent” or “smart” because they are autonomous in optimizing various processes. Be-cause they can modify their behavior without human supervision by analyzing data from the environ-ment, AI-based systems may be more prone to malfunctions and malicious activities than conventional software systems. Moreover, due to existing regulatory gaps, development and operation of AI-based products are not yet subject to adequate risk management and administrative supervision. Resonating to recent reports about potential threats resulting from AI-based systems, this paper presents an outline of a prospective risk assessment for adaptive and autonomous products. This research resulted in exten-sive catalogs of possible damages, initiating events, and preventive policies that can be useful for risk managers involved in conducting risk assessment procedures for AI-based systems. The paper concludes with the analysis and discussion of changes in business, legal, and institutional environments required to ensure the public that AI-based solutions can be trusted, are transparent and safe, and can improve the quality of life.

  • Digital technologies and women's empowerment – casting the bridges
    • Ewa Lechman
    • Piotr Paradowski
    2021 Pełny tekst

    This work briefly discusses the nexuses between digital technology development and adoption across societies, and its potential impact on overall welfare through women’s economic empowerment. In the first section it sets out the context and background. Next, Section 2 demonstrates the state of access to and the use of digital technologies across the world. Section 3 intends to trace the causal links and channels of digital technologies' impact on female empowerment, while the last section shows the problem from the perspective of households.

  • Digital Transformation of Terrestrial Radio: An Analysis of Simulcasted Broadcasts in FM and DAB+ for a Smart and Successful Switchover
    • Przemysław Falkowski-Gilski
    2021 Pełny tekst Applied Sciences-Basel

    The process of digitizing radio is far from over. It is an important interdisciplinary aspect, involving Big Data and AI (Artificial Intelligence) when it comes to classifying and handling content, and an organizational challenge in the Industry 4.0 concept. There exist several methods for delivering audio signals, including terrestrial broadcasting and internet streaming. Among them, the DAB+ (Digital Audio Broadcasting plus) system is one of the leading standards of terrestrial digital radio transmission. Compared with analog FM (frequency modulation) radio, it is more bandwidth efficient and offers greater possibilities when it comes to delivering content and forming an ensemble and multiplex. Currently, many countries worldwide, particularly European States, are still making adjustments in order to perform an efficient switchover from analog FM to digital DAB+ radio. This paper presents the current situation of the digital radio market as well as the results of a subjective quality evaluation study and questionnaire concerning broadcasting in both digital and analog techniques. It involves radio programs, transmitting both speech and music signals, simulcasted in DAB+ and FM standards. It also presents the development of the national multiplex. The results of this study may help both researchers and scientists as well as policy makers and professionals active in the field of broadcasting and electronic media and not to mention the consumption of multimedia content.

  • Diphosphinoboranes as Intramolecular Frustrated Lewis Pairs: P–B–P Bond Systems for the Activation of Dihydrogen, Carbon Dioxide, and Phenyl Isocyanate
    • Natalia Szynkiewicz
    • Anna Ordyszewska
    • Jarosław Chojnacki
    • Rafał Grubba
    2021 Pełny tekst INORGANIC CHEMISTRY

    Herein, we present the first example of the activation of small molecules by P-B-P bond systems. The reactivity study involves reactions of two selected diphosphinoboranes, (tBu2P)2BPh (1’) and (Cy2P)2BNiPr2 (2), that differ in terms of their structural and electronic properties for the activation of dihydrogen, carbon dioxide, and phenyl isocyanate. Diphosphinoborane 1’ activates H2 under very mild conditions in the absence of a catalyst with the formation of the dimer (tBu2PB(Ph)H)2 and tBu2PH. Conversely, diphosphinoborane 2 did not react with H2 under the same conditions. The reaction of 1’ with CO2 led to the formation of a compound with an unusual structure, where two phosphinoformate units were coordinated to the PhBOBPh moiety. In addition, 2 reacted with CO2 to insert two CO2 molecules into the P-B bonds of the parent diphosphinoborane. Both diphosphinoboranes activated PhNCO, yielding products resulting from the addition of two and/or three PhNCO molecules and the formation of new P-C, B-O, B-N, and C-N bonds. The products of the activation of small molecules by diphosphinoboranes were characterized with nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy, single-crystal X-ray diffraction, and elemental analysis. Additionally, the reaction mechanisms of the activation of small molecules by diphosphinoboranes were elucidated by theoretical methods.

  • Dipodal Tetraamide Derivatives of 1,10-Diaza-18-Crown-6 and Alkylmalonic Acids—Synthesis and Use as Ionophores in Ion Selective Membrane Electrodes
    • Radosław Pomećko
    • Elżbieta Luboch
    • Maciej Jeszke
    2021 Pełny tekst SENSORS

    Novel dipodal derivatives of an 18-membered diaza-crown ether with two diamide chains featuring methylmalonic or butylmalonic acid residues were obtained and tested as ionophores in ion-selective plasticized membrane electrodes. The objective of the study was to identify measurement conditions which ensure the most favorable performance for magnesium ion-selective electrodes. The relationship between the molar lipophilic anion salt-to-ionophore ratio and selectivity of electrodes was examined. The best result was obtained for the conventional electrode containing Mg2 ionophore. Calculated selectivity coefficients were as follows: logKMg/Ca = −2.77, logKMg/Na = −3.46 and logKMg.K = −2.24 (SSM, 1M)

  • Direct electrical stimulation of the human brain has inverse effects on the theta and gamma neural activities
    • Michał Lech
    • Brent Michael Berry
    • Cagdas Topcu
    • Vaclav Kremen
    • Petr Nejedly
    • Bradley Lega
    • Robert E. Gross
    • Michael R. Sperling
    • Barbara C. Jobst
    • Sameer A. Sheth
    • Kareem Zaghloul
    • Kathryn A. Davis
    • Gregory A. Worrell
    • Michał Kucewicz
    2021 Pełny tekst IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING

    Objective: Our goal was to analyze the electrophysiological response to direct electrical stimulation (DES) systematically applied at a wide range of parameters and anatomical sites, with particular focus on neural activities associated with memory and cognition. Methods: We used a large set of intracranial EEG (iEEG) recordings with DES from 45 subjects with electrodes implanted both subdurally on the cortical surface and subcortically into the brain parenchyma. Subjects were stimulated in blocks of alternating frequency and amplitude parameters during quiet wakefulness. Results: Stimulating at different frequencies and amplitudes of electric current revealed a persistent pattern of response in the slow and the fast neural activities. In particular, amplification of the theta (4–7 Hz) and attenuation of the gamma (29–52 Hz) power-in-bandwas observed with increasing the stimulation parameters. This opposite effect on the low and high frequency bandswas found across a network of selected local and distal sites proportionally to the proximity and magnitude of the electric current. Power increase in the theta and decrease in the gamma band was driven by the total electric charge delivered with either increasing the frequencyor amplitudeof the stimulation current. This inverse effect on the theta and gamma activities was consistently observed in response to different stimulation frequencies and amplitudes.Conclusion: Our results suggest a uniform DES effect of amplifying theta and suppressing gamma neural activitiesin the human brain. Significance: These findingsreveal the utility of simple power-in-band features forunderstanding and optimizing the effects of electrical stimulationon brain functions.

  • Direct spectrum detection based on Bayesian approach
    • Beata Pałczyńska
    • Dariusz Świsulski
    2021 Pełny tekst Przegląd Elektrotechniczny

    The paper investigates the Bayesian framework's performance for a direct detection of spectrum parameters from the compressive measurements. The reconstruction signal stage is eliminated in by the Bayesian Compressive Sensing algorithm, which causes that the computational complexity and processing time are extremely reduced. The computational efficiency of the presented procedure is significantly better than a typical compressive sensing approach. The numerical simulations confirm the possibility of using this method to direct harmonics detection.