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Recent items
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Sensitive Demonstration of the Twin-Core Couplers including Kerr Law Non-Linearity via Beta Derivative Evolution
- Adeel Asad
- Muhammad Riaz
- Yanfeng Geng
To obtain new solitary wave solutions for non-linear directional couplers using optical meta-materials, a new extended direct algebraic technique (EDAT) is used. This model investigates solitary wave propagation inside a fiber. As a result, twin couplers are the subject of this study. Kerr law is the sort of non-linearity addressed there. Because it offers solutions to problems with large tails or infinite fluctuations, the resulting solution set is more generalized than the current solution because it is turned into a fractional-order derivative. Furthermore, the found solutions are fractional solitons with spatial–temporal fractional beta derivative evolution. In intensity-dependent switches, these nonlinear directional couplers also serve as limiters. Non-linearity alters the transmission constants of a system’s modes. The significance of the beta derivative parameter and mathematical approach is demonstrated graphically, with a few of the extracted solutions. A parametric analysis revealed that the fractional beta derivative parameter has a significant impact on the soliton amplitudes. With the aid of the advanced software tools for numerical computations, the categories of semi-dark solitons, singular dark-pitch solitons, single solitons of Type-1 along with 2, intermingled hyperbolically, trigonometric, and rational solitons were established and evaluated. We also discussed sensitivity analysis, which is an inquiry that determines how sensitive our system is. A comparative investigation via different fractional derivatives was also studied in this paper so that one can easily understand the correlation with other fractional derivatives. The findings demonstrate that the approach is simple and efficient and that it yields generalized analytical results. The findings will be extremely beneficial in examining and comprehending physical issues in nonlinear optics, specifically in twin-core couplers with optical metamaterials.
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Sensors and System for Vehicle Navigation
- Andrzej Stateczny
- Witold Kazimierski
- Pawel Burdziakowski
In recent years, vehicle navigation, in particular autonomous navigation, has been at the center of several major developments, both in civilian and defense applications. New technologies, such as multisensory data fusion, big data processing, or deep learning, are changing the quality of areas of applications, improving the sensors and systems used. Recently, the influence of artificial intelligence on sensor data processing and understanding has emerged. Radar, LiDAR, visual sensors, sonar systems, and other sensors are mounted onboard smart and flexible platforms and on several types of unmanned vehicles in all types of environments. These technologies focusing on vehicle navigation may encounter many common scientific challenges. Particularly interesting is autonomous navigation for non-GNSS applications, such as underwater and indoor vehicle navigation. The Special Issue entitled “Sensors and System for Vehicle Navigation” focused on many aspects of vehicle navigation, such as autonomous navigation, multisensor fusion, big data processing for vehicle navigation, sensors related to science/research, algorithms/technical development, analysis tools, synergy with sensors in navigation, data fusion, and artificial intelligence methods for navigation.
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Separation and determination of the group-type composition of modern base and lubricating oils with a wide range of polarity, especially emitted to the environment
- Paulina Dyguła
- Karolina Kucharska
- Marian Kamiński
Lubricating oils are composed of base oils (>85% v/v) and enriching additives (<15% v/v). Three types of base oils may be distinguished: 1) traditional bases (obtained by low-volatile fractions from crude oil distillation refining), 2) synthetic bases (mainly poly-alpha-olefins, sometimes esters, especially succinic acid esters), 3) bases of natural origin (especially obtained from refined plant oils). The bases of natural origin are the only ones recommended for application when lubricating oil may be emitted to the environment (e.g. when the machine with an open cutting system is used). Group-type separation and analysis of group-type composition of base and lubricating oils are of significant importance in quality control and environmental monitoring. Due to the potentially wide range of polarity of the components of base and lubricating oils, group- type separation becomes a difficult separation problem. It is also a serious analytical problem due to the considerable diversity of physicochemical properties. The authors propose a new procedure for the separation and determination of the group-type composition of base and lubricating oils using thin-layer liquid chromatography in normal phase systems (abr. NP-TLC) on silica gel plates impregnated with berberine salt/in the coupling of thin-layer chromatography with flame ionization detection (abr. TLC-FID). A new, effective procedure of TLC plates impregnation with berberine sulphate was presented. The proposed procedure ensures the visualization of all groups of base oils. Extensive experimental research showed that a 2-step development procedure with application of n-hexane up to 100% height of development +15 min and further n-hexane: isopropanol: tri-fluoroacetic acid 96.25: 3: 0.75 (v: v: v) up to 75% height of development is advantageous for the group-type separation, both in TLC-FID and TLC.
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SFEM Analysis of Beams with Scaled Lengths including Spatially Varying and Cross-Correlated Concrete Properties
- Ewelina Korol
This paper presents the results obtained for plain concrete beams under four-point bending with spatially varying material properties. Beams of increasing length but constant depth were analyzed using the stochastic finite element method. Spatial fluctuation of a uniaxial tensile strength, fracture energy and elastic modulus was defined within cross-correlated random fields. The symmetrical Gauss probability distribution function was applied for the material properties. The shape of the probability distribution function was modified by changing the coefficient of variation in order to find its right value. The correctness of the numerical solution was verified against the experimental results of Koide et al. (1998, 2000). The stochastic FEM analysis was performed with an autocorrelation length of 40 mm and material coefficients of variation of 0.12, 0.14, 0.16, 0.20 and 0.24. The comparison between numerical outcomes and experimental results demonstrated that the coefficient of variation of 0.24 gave the best agreement when referring to the experimental mean values. On the other hand, the variation of results was better captured with the coefficient of variation of 0.16. The findings indicate that the Gauss probability distribution function with cov = 0.24 correctly reproduced the statistical size effect, but its tails needed modification in order to project experimental result variation.
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Shaking table experimental study on pounding between adjacent structures founded on different soil types
- Mahmoud Miari
- Robert Jankowski
The aim of this study is to extensively investigate the effect of the soil type on the response of colliding structures based on shaking table experimental tests. Two single-storey models of steel buildings with different dynamic parameters were considered in this study. Three pounding scenarios were taken into account by applying different seismic gaps (0.5 cm, 1 cm and 1.5 cm as well as the no pounding case). First, the effect of pounding on the response of these two structures was analysed. Then, the effect of the seismic gap on the response of colliding structures was studied. Finally, the effect of soil type on the response of structures exposed to interactions was investigated. Five soil types were considered in the study, which are the five soil types defined in the ASCE 7-10 code (hard rock, rock, very dense soil and soft rock, stiff soil and soft clay soil). The results of the investigation show that pounding significantly increases the level of accelerations of structures during the whole time of vibrations as well as the peak acceleration itself. Pounding is more significant for the flexible structure than for the stiff one. Also, the seismic gap has a significant effect on the acceleration response of colliding structures. Not necessarily larger gap leads to lower responses unless it is large enough to eliminate collisions at all. Moreover, the results of the study show that the soil type has a significant effect on the response of colliding structures. The soil type effect is more significant when pounding takes place. The maximum and minimum peak acceleration differs for various soil types, pounding scenarios, seismic gaps and earthquakes.
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Sharing research data across disciplines
2022 Full textThis monograph is a collection of experiences gathered by the team implementing the Bridge of Data project. However, it is not just a simple summary of the project implementation. It shows and systematizes the substantive and technical works performed by the teams and several issues related to data management itself in various disciplines, represented by members of the scientific team and other researchers from partner universities.The aim of an attempt to describe as much data as possible and the diversity thereof was to approximate to the reader of this publication both the complexity of research processes and data acquisition methods in different disciplines. Thus, it also shows various data types, formats, and methods – collection, description, and sharing. The importance of ensuring that the results of research in the form of data are not lost is increasingly emphasized. There is also a growing awareness among researchers themselves, though not everywhere and not at the same pace. Some funding bodies have defined requirements that plans for managing the data (Data Management Plans) produced during a research project should be included in grant proposals. These plans show how research data will be collected, organized, managed, and preserved during the project and after. What such a plan looks like depends on the specificity and conditions of the project
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Shrinking-shifting and amplifying-shifting device using transformation optics
- Hamza Madni
- Slawomir Koziel
- Muhammad Musavir Bilal
- Muhammad Afzal
- Farrukh Jaleel
- Ahmed Sohaib
- Wei Xiang Jiang
Based on transformation optics (TO), this paper uses geometric divisions and linear coordinate transformations to design “shrinking-shifting—and reshaping”, and “amplifying-shifting—and reshaping” devices. The proposed devices can reshape the sizes and locations of the wrapped-objects inside the core-region. The shrinking-shifting device shrinks the larger object into a smaller one and shifts it to different location, whereas the shrinking-reshaping device can generate a smaller-size image with different shape located at different location. In contrast to previously designed shrinking devices, the real object wrapped inside the proposed core-region and the transformed object contains the same material properties, and the location-shifting is another feature. Here, the shifting-region is located inside the physical-space boundaries to achieve the non-negative, homogeneous, and anisotropic material properties of the proposed device, which are easier for real implementations. Thus, we further verified this concept with the amplifying-shifting and -reshaping devices for visually transformation of smaller object into bigger one placed at different location and position. We also applied active scatterer to further validate the working functionality of proposed devices. In addition, the proposed devices behave like the concentrator and (or) rotator effect in the absence of any scatterer. Our findings highlight the role of TO, suggesting directions for future research on bi-functional devices that will be useful for shrinking and amplifying devices, illusion optics, camouflage, and object protection etc.
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Side Effects of National Immunization Program: E-Governance Support Toward Elders' Digital Inclusion
- Magdalena Ciesielska
- Nina Rizun
- Anna Baj-Rogowska
In response to the coronavirus pandemic, the European Union (EU) governments develop policies to regulate exclusive health protection actions that consider societal needs with the emphasis on elders. Given that the EU vaccination strategy uses a centralized ICT-based approach, there is little guidance on how seniors are included in national immunization programs (NIP). In this paper, we addressed a knowledge gap of the side effects of e-governance of NIP for the elderly. To fill this gap, we identified 40 side effects by analyzing online textual opinions (tweets, comments, articles) that express public perception regarding the results of the Polish NIP implementation to seniors' digital inclusion, categorized them into 8 categories and assign them to four e-governance functions. The main contribution of this paper is a better understanding of the digital divide and to provide guidelines for government policy improvement.
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Signals Features Extraction in Radioisotope Liquid-Gas Flow Measurements using Autocorrelation Function
- Robert Hanus
- Marcin Zych
- Anna Golijanek-Jędrzejczyk
Knowledge of the two-phase flow structure is essential for the proper conduct of industrial processes. Description of liquid-gas flow regimes is possible by using of data analysis in time, frequency, or state-space domain. In this research studies, the autocorrelation function is applied for analysis of signals obtained for liquid-gas flow by use gamma-ray absorption. The experiments were carried out on the laboratory hydraulic installation fitted with Am-241 radioactive source and scintillation probe with NaI(Tl) crystal. Four types of flow regimes as plug, slug, bubble, and transitional plug - bubble were studied in this work. It was found that the selected amplitudes of the normalized autocorrelation function are helpful to recognize the flow regime.
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Significance of Dermoscopy in Association with Clinical Features in Differentiation of Basal Cell Carcinoma and Benign Trichoblastic Tumours
- Martyna Sławińska
- Anna Płaszczyńska
- Joanna Lakomy
- Krzysztof Pastuszak
- Wojciech Biernat
- Monika Sikorska
- Roman J. Nowicki
- Michał Sobjanek
Background: Although basal cell carcinoma (BCC) can, in the majority of cases, be diagnosed based on clinical and dermoscopic assessment, a potential overlap with benign adnexal skin tumours seems to exist, including trichoblastic tumours (TT). Methods: Retrospective analysis of clinical and dermoscopic features of benign TT and BCC cases was performed to develop a diagnostic algorithm with a potential utility in clinical practice. Results: In the study, 502 histopathologically confirmed BCC cases were compared with 61 TT (including 44 TB (72.13%), 10 TE (16.39%) and 7 DTE (11.48%]). Patients in the BCC group were statistically older (mean age was 71.4 vs. 64.4 years, respectively; p = 0.009). BCC presented generally as larger tumours (mean tumour size 11.0 vs. 8.2 mm for the TT group; p = 0.001) and was more frequently associated with clinically visible ulceration (59.4% vs. 19.7%, respectively; p < 0.001). Comparison of lesion morphology, clinically visible pigmentation, and anatomical location did not show significant differences between the analysed groups. Dermoscopically visible ulceration was significantly more common in the BCC group compared to the TT group (52.2% vs. 14.8%; p < 0.0001). Pigmented structures, specifically brown dots and brown globules, were significantly more prevalent in the TT group (32.8% vs. 11.4%; p = 0.0001 and 29.5% vs. 8.2%; p <0.0001). Similarly, TT more commonly than BCC showed the presence of cloudy/starry milia-like cysts (26.2% vs. 11.6%; p = 0.0031) and yellow globules (16.4% vs. 7.2%; p = 0.033). Conclusions: Despite differences in frequency of clinical and dermoscopic features between BCC and TT in the studied group, differential diagnosis based on these variables is not reliable. Histopathological examination remains a diagnostic gold standard in differentiation of BCC and TT.
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Silicon oxycarbide-tin nanocomposite derived from a UV crosslinked single source preceramic precursor as high-performance anode materials for Li-ion batteries
- Dominik Knozowski
- Pradeep Vallachira Warriam Sasikumar
- Romain Dubey
- Marcel Aebli
- Kostiantyn V. Kravchyk
- Grzegorz Trykowski
- Maksym V. Kovalenko
- Thomas Graule
- Monika Wilamowska-Zawłocka
- Gurdial Blugan
In this work, we report an innovative and facile UV light-assisted synthesis of a nanocomposite based on silicon oxycarbide (SiOC) and tin nanoparticles. SiOC ceramic matrix, containing a conductive free carbon phase, participates in lithium-ion storage, and buffers the volume changes of Li-alloying/de-alloying material. The reported synthesis procedure through a polymer-derived ceramic route involves the preparation of a single-source precursor by UV crosslinking of a preceramic polymer in the presence of a tin precursor. Pyrolysis of this starting precursor at 1000 °C leads to a homogenous distribution of tin nanoparticles (25–35 nm) within the SiOC ceramic matrix, which is crucial for electrochemical stability of the material. SiOC/Sn nanocomposite tested as an anode for Li-ion battery exhibits high reversible capacity values (603 mAh g−1 at the current density of 74.4 mA g−1), outstanding rate capability (524 mAh g−1 at 2232 mA g−1), and superior stability (494 mAh g−1 after 250 charge/discharge cycles).
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Simple Millimeter Wave Identification System Based on 60 GHz Van Atta Arrays
- Kamil Trzebiatowski
- Mateusz Rzymowski
- Łukasz Kulas
- Krzysztof Nyka
The paper presents a proof-of-concept of a millimeter-wave identification system based on Van Atta array tags in the 60 GHz band. For interrogation of the tags, a vector network analyzer and a measurement transceiver were employed in alternative test configurations. The design, fabrication and measurements of co- and cross-polarized Van Atta arrays are presented in the paper. They can be treated as simple chipless RFID tags with frequency-response-based identification. Tags with various resonance frequencies are designed by scaling an optimized base model. The designed 57–67 GHz co-polarized and cross-polarized tags have small dimensions of approximately 23 mm 21 mm and 40 mm 25 mm, and they exhibit radar cross-section (RCS) levels of 16 dBsm and 21 dBsm, respectively. Owing to the retrodirective properties of Van Atta arrays, the RCS can be maintained at a high level within a broad range of angles of incidence. The system was validated in an anechoic chamber where the spectral responses of all the manufactured tags can be clearly distinguished from the environment, enabling their identification. Tests in a reflective environment were also performed, and they have shown that only the cross-polarized tags could be detected and identified in the presence of reflections from the tags’ surroundings.
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Simple synthesis route for fabrication of protective photo‐crosslinked poly(zwitterionic) membranes for application in non‐enzymatic glucose sensing
- Adrian Olejnik
- Jakub Karczewski
- Anna Dołęga
- Katarzyna Siuzdak
- Adam Cenian
- Katarzyna Grochowska
This work focuses on the fabrication of non-enzymatic glucose sensing materials based on laser-formed Au nanoparticles embedded in Ti-textured substrates. Those materials possess good catalytic activity toward glucose oxidation in 0.1 × phosphate buffered saline as well as resistance to some interferants, such as ascorbic acid, urea, and glycine. The electrodes are further coated with three different polymers, that is, Nafion, photo-crosslinked poly(zwitterions) based on sulfobetaine methacrylate, and a hybrid membrane consisting of both polymers. Both the optimal integrity of the material and its catalytic activity toward glucose oxidation were maintained by the hybrid membranes with a large excess of poly(zwitterions) (mass ratio 20:1). The chemical structures of the as-formed membranes are confirmed by Fourier transform infrared spectroscopy. Due to the zwitterionic nature of the coating, the electrodes are resistant to biofouling and maintain electrochemical activity toward glucose for 4 days. Moreover, due to the synergistic effect of both Nafion and poly(zwitterions), the interference from the two compounds, namely, from acetylsalicylic acid and acetaminophen, was diminished. Besides the presence of polymer membranes, the electrode possesses a sensitivity of 36.8 μA cm−2 mM−1 in the linear range of 0.4–12 mM, while the limit of detection was estimated to be 23 μM. Finally, the electrodes are stable, and their response is not altered even by 1,000 bending cycles.
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SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
- Przemysław Sorn
- Mateusz Sondej
- Jarosław Górski
Fuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing for its optimization.
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Simplified Numerical Model for Transient Flow of Slurries at Low Concentration
- Katarzyna Weinerowska-Bords
- Apoloniusz Kodura
- Michał Kubrak
Rapid transients are particularly dangerous in industrial hydro-transport systems, where solid-liquid mixtures are transported via long pressure pipelines. A mathematical description of such flow is difficult due to the complexity of phenomena and difficulties in determining parameters. The main aim of the study was to examine the influence of the simplified mixture density and wave celerity description on satisfactory reproduction of pressure characteristics during the transient flow of slurry at low concentrations. The paper reports and discusses the selected aspects of experimental and numerical analyses of transient slurry flow in a polyethylene pipe. The experiments were conducted by using the physical model of a slurry’s transportation pressure. The aim of the experiments was to determine the wave celerity during a transient flow in slurries. A low concertation of slurries, which was used during experiments, is typical for one of the biggest slurry networks in Poland. A comparison of the effects of different wave celerity descriptions was performed. The research reported that the theoretical formulas for slurry wave celerity and mixture density were not sufficiently accurate to obtain satisfactory compliance between calculations and observations. To improve the model, the experimental values of wave celerity and the concept of equivalent mixture density have been applied to indirectly consider the influence of variable mixture parameters. With such modifications, the calculated pressure characteristics in all analyzed episodes demonstrated satisfactory compliance with observations. The simplified approach proved to be effective in properly reproducing the intensity and frequency of rapid pressure changes.
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Simulation of hybridized nanofluids flowing and heat transfer enhancement via 3-D vertical heated plate using finite element technique
- Muhammad Bilal Hafeez
- Marek Krawczuk
- Hasan Shahzad
- Amjad Ali Pasha
- Mohammad Adil
The present study probed the creation of heat energy and concentrating into Newtonian liquids across vertical 3D-heated plates. The role of the Soret and Dufour theories in concentrating and energy formulas is discussed. The role of hybrid nanoparticles is introduced to illustrate particle efciency in terms of solute and thermal energy. It is removed a viscous dissipation process and a changing magnetic feld. The proposed approach is motivated by the need to maximize solute and thermal energy uses in biological and industrial domains. The constructed system of (partial diferential equations) PDEs includes concentration, momentum, and thermal energy equations within various thermal characteristics. Transformations are used to formulate the system of (ordinary diferential equations) ODEs for solution. To assess various features vs various variables, a Galerkin fnite element approach is used. Motion into nanoscale components is shown to be smaller than motion into hybrid nanoparticles. Furthermore, fuctuations in heat energy and solute particle counts are seen in relation to changes in Soret, Eckert, magnetic, and Dufour numbers. The basic fnding is that the generation of thermal energy for hybridized nanomaterials is much higher.
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Simulations of the Derecho Event in Poland of 11th August 2017 Using WRF Model
- Mariusz Figurski
- Grzegorz Nykiel
This series contains datasets related to the forecasting of a severe weather event, a derecho, in Poland on 11 August 2017. The simulations were conducted using the Weather Research and Forecasting (WRF) model version 4.2.1 with different initial and boundary conditions of the pressure and model levels derived from 5 global models: Global Forecast System (GFS), Global Data Assimilation System (GDAS), European Centre for Medium-Range Weather Forecasts (ECMWF), and ERA5. Each simulation, shared as a separate dataset, was performed for two starting hours: at 00:00 and 12:00 UTC. The datasets contain about 280 meteorological parameters stored as 2D or 3D fields with high-spatial (2.5 km and 0.5 km domains) and temporal (10 minutes) resolutions. The three-dimensional fields are calculated at 50 levels up to 50 hPa. All data are stored in easily accessible NetCDF files.
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Simultaneous removal of heavy metals and dyes in water using a MgO-coated Fe3O4 nanocomposite: Role of micro-mixing effect induced by bubble generation
- Manoj Panayamthatta Rayaroth
- Dasom Oh
- Chung-seop Lee
- Yoon-seok Chang
This study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly Fe3O4@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb2+) and a dye, rhodamine B (RhB). The addition of H2O2 into the system enabled the self-mixing of the aqueous solution containing Fe3O4@MgO through the generation of bubbles. This system showed an excellent removal efficiency of 99% in just 15 min for Pb2+ and 120 min for RhB, which is far better than the control experiment (without H2O2). The cation exchange mechanism dominated in the removal of heavy metals, while the adsorptive removal of dye proceeded through the H-bonding between Mg(OH)2 and dye molecules. The removal efficiency increased exponentially with the increase of H2O2 at the optimal concentration of 5% and it was effective over a wide pH range. Moreover, the performance of the Fe3O4@MgO-H2O2 system was verified for other heavy metals such as Cd, Ni, Zn, Co, and Cu, demonstrating that the Fe3O4@MgO-H2O2 system can be widely implemented in the treatment of real water matrices contaminated with heavy metals and organic dyes.
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Single and Series of Multi-valued Decision Diagrams in Representation of Structure Function
- Michal Mrena
- Miroslav Kvassay
- Stanisław Czapp
Structure function, which defines dependency of performance of the system on performance of its components, is a key part of system description in reliability analysis. In this paper, we compare two approaches for representation of the structure function. The first one is based on use of a single Multi-valued Decision Diagram (MDD) and the second on use of a series of MDDs. The obtained results indicate that the series of MDDs can be more efficient than a single MDD in case of series-parallel systems, which belong to the most fundamental types of topologies studied by reliability engineers.
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Single-phase, Five-level Inverter with SPWM-Based Neutral Point Voltage Balancing Scheme
- Dmytro Kondratenko
- Arkadiusz Lewicki
- Charles Odeh
Multilevel inverter topologies provide several advantages over two-level inverter configuration. These benefits are the reason for the growing interest in multilevel topologies among research society. One of the most popular topological concepts (diode and active switch clamping) requires neutral-point potential balancing due to series-connected capacitor banks across the input dc link in such derived inverter configurations. This paper presents a Sinusoidal PWM (SPWM) scheme that ensures balanced and reduced input capacitor voltages' variations in single-phase T-type inverter. Comparison analyses with existing carrier-based pulse-width modulation methods are provided. Simulation results are provided which showcase the effectiveness of the control approach. Experimental validation of these results was provided with a five-level single-phase T-type VSI; that supplies single-phase RL load.
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Size effect at aggregate level in microCT scans and DEM simulation – Splitting tensile test of concrete
- Jan Suchorzewski
- Michał Nitka
The paper describes an experimental and numerical study of size effect on concrete cylindrical specimens in splitting tensile test. Own experimental campaign was performed on specimens with 5 various diameters from D = 74, 105, 150, 192 and 250 mm with hardboard loading strips (distributed load according to standard methods) scaled proportionally to the specimen diameter. The crack opening-control system was applied to obtain the post-peak behaviour of all tested specimens including catastrophic behaviour (snap-back). The tested specimens at a certain point were unloaded and scanned with novel high-resolution micro tomography to analyse the macro cracks and phenomena like aggregate breakage, crack branching etc. at the aggregate level. Based on realistic mesostructure the discrete element method (DEM) 2D model of 3 specimens with diameters of D = 74, 150 and 250 mm were constructed and tested. The fracture was analysed at macro and micro-level in DEM and directly compared with microCT scans. DEM simulations revealed additional information related to the loss of material strength and ductility with increasing specimen size (size effect). The simulation and experimental results were in good agreement.
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Skills mismatch in the context of technological change
- Franciszek Kutrzeba
The main purpose of this dissertation is to assess the perception asymmetry of smart skills and formal education in ICT based economy. In other words, the goal of this research is to assess perceptions of smart skills and competences in the context of technological change from the perspectives of employers and students in Poland. Determining the fore-mentioned relationship gives insight into the hypothetical perception asymmetry for demanded smart skills in an ICT-based economy with possible practical implications for policymakers and educators. I have defined the following research questions: 1. What is the interrelation of perceptions on smart skills and competences between Polish higher education students and employers in Poland? 2. What is the significance of formal education in the context of recent technological change?
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Slowly-closing valve behaviour during steam machine accelerated start-up
- Mateusz Bryk
- Mariusz Banaszkiewicz
- Tomasz Kowalczyk
- Waldemar Dudda
- Paweł Ziółkowski
The paper discusses the state of stress in a slowly-closing valve during accelerated start-up of a steam turbine. The valve is one of the first components affected by high temperature gradients and is a key element on which the power, efficiency and safety of the steam system depend. The authors calibrated the valve model based on experimental data and then performed extended Thermal-FSI analyses relative to experiment. The issue is important as determining the possibility of accelerating the start-up of a steam turbine while not exceeding the strength limit in the design of the steam valve. The shorter the startup time, the more environmental and economic benefits. The most important results of the work include the possibility to reduce the start-up time of a steam machine without excessive strain on the valve structural components and not to exceed the stress limits. The important news for the industry is that there is no need to change the valves construction in terms of accelerated start-up of the steam engine. The results of the work confirm the belief that fast start-up of a steam turbine is possible without large capital expenditures for design changes in the components of the steam system.
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Small Polymeric Toys Placed in Child-Dedicated Chocolate Food Products—Do They Contain Harmful Chemicals? Examination of Quality by Example of Selected VOCs and SVOCs
- Monika Śmiełowska
- Mariusz Marć
- Bożena Zabiegała
This study was focused on child-dedicated chocolate food products that contain a plastic package with a small toy inside (also known as chocolate eggs). Three types of these products that are commercially available on the Polish market, with different prices, chocolate composition, and main types of polymers used in the toy manufacturing process, were investigated. The polymers were identified using Fourier-transform infrared (FT-IR) analysis and emissions of selected toxic volatile organic compounds of toy and packaging samples were identified using stationary emission micro-chamber. Total volatile organic compounds emissions were also estimated. Moreover, the content of polybrominated diphenyl ethers (PBDEs) as bioaccumulative semi-volatile organic compounds was checked in all parts of the cheapest product. The highest PBDE concentra- tions, which ranged from 5.32 ± 0.79 to 1768 ± 289 ng/g, were recorded in chocolate samples. This demonstrates the need for consumer knowledge on the safety of such products available on the Polish market to be broadened. This is one of the many examples of studies showing that products sold on the European market do not always comply with the Conformité Européenne (CE) declaration of conformity. Furthermore, the presence of phased-out PBDEs in toys may provide evidence of wrong recycling practices. Forward-looking considerations showed that, based on assessments of the hazard quotient (HQ) and cancer risk of BDE-209 and assuming each child has contact with one toy and eats one of the studied chocolate products per day, there is no high risk associated with the exposure of children to PBDEs.
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Smart Knowledge Engineering for Cognitive Systems: A Brief Overview
- Caterine Silva de Oliveira
- Cesar Sanin
- Edward Szczerbicki
Cognition in computer sciences refers to the ability of a system to learn at scale, reason with purpose, and naturally interact with humans and other smart systems, such as humans do. To enhance intelligence, as well as to introduce cognitive functions into machines, recent studies have brought humans into the loop, turning the system into a human–AI hybrid. To effectively integrate and manipulate hybrid knowledge, suitable technologies and guidelines are required to sustain the human–AI interface so that communication can occur. However, traditional Knowledge Management (KM) and Knowledge Engineering (KE) approaches encounter problems when dealing with cutting-edge technologies, imposing impediments for the use of traditional methods in cognitive systems (CS). This paper presents a brief overview of the Smart Knowledge Engineering for Cognitive Systems (SKECS), which is based on methods, technologies, and procedures that bring innovations to the fields of KE, KM, and CS. The goal is to bridge the gap in the hybrid cognitive interface by the combination of experience-based knowledge representation with the use of emerging technologies such as deep learning, context-aware indexing/retrieval, active learning with a human-in-the-loop, and stream reasoning. In this work Set of Experience Knowledge Structure (SOEKS) and Decision DNA (DDNA) is extended to the visual domain and utilized for knowledge capture, representation, reuse, and evolution. These technologies are examined throughout the layers of SKECS for applications in knowledge acquisition, formalization, storage/retrieval, learning, and reasoning, with the final goal of achieving knowledge augmentation (wisdom) in CS. Features of the SKECS and their practical implementation is discussed through a case study—the Cognitive Vision Platform for Hazard Control (CVP-HC)—suggesting that methods, techniques and procedures comprising the SKECS are suitable for advancing systems toward augmented cognition.
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Smart Virtual Product Development: Manufacturing Capability Analysis and Process Planning Module
- Muhammad Ahmed
- Cesar Sanin
- Edward Szczerbicki
Smart Virtual Product Development (SVPD) system provides effective use of information, knowledge, and experience in industry during the process of product development in Industry 4.0 scenario. This system comprises of three primary modules, each of which has been developed to cater to a need for digital knowledge capture for smart manufacturing in the areas of product design, production planning, and inspection planning. Manufacturing Capability Analysis and Process Planning (MCAPP) module is an important module of the SVPD system, and it involves the provision of manufacturing knowledge to experts working on product development at the early stages of the product lifecycle. In this research, we firstly describe the structure and working mechanism of the SVPD system’s MCAPP module. This is followed by validation of the MCAPP module’s Manufacturing Process Planning (MPP) sub-module against the key performance indicators (KPIs) by using our threading tap case study. Our results verify the feasibility of our approach and show how manufacturing knowledge relating to features and functions can be used to enhance the manufacturing process across similar products during the early stages of product development. An analysis of the basic concepts and methods of implementation show that this is an expert system capable of supporting smart manufacturing which can play a vital role in the establishment of Industry 4.0.
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SnO2 nanoparticles embedded onto MoS2 nanoflakes - An efficient catalyst for photodegradation of methylene blue and photoreduction of hexavalent chromium
- Mariusz Szkoda
- Zuzanna Zarach
- Małgorzata Nadolska
- Grzegorz Trykowski
- Konrad Trzciński
In this work, a molybdenum disulfide/tin oxide (MoS2/SnO2) composite was successfully prepared via a hydrothermal method. The MoS2/SnO2 composite was used as a photocatalyst for photoreduction of hexavalent chromium and photodecomposition of methylene blue. It exhibited higher photocatalytic performance under simulated solar light irradiation than MoS2 itself. The obtained material was characterized by several spectroscopic and microscopic techniques, namely X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). TEM images of the MoS2/SnO2 revealed that SnO2 nanoparticles were embedded into MoS2. Furthermore, photodegradation mechanism and the role of adsorption were discussed. The enhanced photocatalytic performance of MoS2/SnO2 composite can be directly attributed to the presence of SnO2, which may increase the separation efficiency of the electron-hole pairs. The 99.5% of MB removal was achieved after 5 minutes of illumination. To the best of our knowledge, it is one of the most photoactive MoS2-based photocatalysts for methylene blue (MB) photodecomposition. Moreover, the obtained composite was highly active against chromium (VI) photo-reduction. This work provides evidence that the MoS2/SnO2 composite possesses enormous potential in photocatalytic applications.
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Social Capital, Human Capital, Tacit Knowledge, and Innovations: A Polish-US Cross-Country Study
- Wioleta Kucharska
- G. Scott Erickson
This study measures the relationship between human and social capital (internal and external) and tacit knowledge sharing's influence on innovativeness among knowledge workers employed in Polish (n=1050) and US (n=1118) organizations. The structural equation modeling method revealed that internal social capital matters more for organizational innovativeness in the US. In Poland, both external and internal were important. Specifically, in the US, external social capital supports internal innovativeness directly and external - indirectly. On the contrary, in Poland, social capital directly influences internal and external innovativeness. These differences are partially due to country differences regarding public and private financing. Also apparent is the need for strong social bonds between employees in innovative companies. Furthermore, this study confirms that internal innovativeness is vital for external innovativeness and reveals that social capital is a structural enabler for innovativeness, given its critical role in the distribution of tacit knowledge.
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Social learning in cluster initiatives
- Małgorzata Rozkwitalska
- Anna Lis
Purpose – The purpose of the paper is to portray social learning in cluster initiatives (CIs), namely: 1) to explore, with the lens of the communities of practice (CoPs) theory, in what ways social learning occurs in CIs; 2) to discover how various CoPs emerge and evolve in CIs to facilitate a collective journey in their learning process. Subsequently, the authors address the research questions: In what ways does social learning occur in CIs? How is social learning facilitated through the emergence and evolution of various CoPs in CIs? Design/methodology/approach – The study applies the abduction approach for the interpretation of the collected data and attempts to create the best explanations for the observations on the basis of the CoP theory. The qualitative study of four CIs helped to identify various ways that social learning occurs in CIs and the role of the identified CoPs in the process. Social learning is portrayed as a collective journey within and between CoPs, where the interactions of their members deepen their level of involvement and help them to enhance learning in their CoP. Findings – The paper shows ways that social learning occurs in CIs and describes the role of CoPs. It identifies three types of CoPs in CIs: participants, cooperators and locomotives. Additionally, it documents different ways of social learning in CIs, namely one-way or two-way information transfer and raising awareness, demonstrating and inspiring, or motivating and educating. It also shows that while potentially every member of a CI has access to these practices, only a limited number of members are actually involved. Social learning in CIs is selective and some CI members accept their role as more peripheral in their CI. Originality/value – The literature on CIs, which are peculiar forms of clusters, is still underdeveloped. The research fills in the gap concerning the ways social learning occurs in CIs. It shows that selectiveness can be observed in this process, and emphasizes the role of interactions developed through CoPs and the benefits offered by them. The study applies the CoP approach. Consequently, it expands the theoretical base in view of the generally lacking studies on social learning in CIs in the literature on clustering. Since the CoP theory has rarely been applied in the management literature, it also augments this specific field.
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Social Learning in Cluster Organizations and Accumulation of Technological Capability
- Małgorzata Rozkwitalska
- Anna Lis
The purpose of the paper is to present how members of cluster organizations perceive their role in the accumulation of technological capability through social learning. The paper presents the results of a qualitative study of four cluster organizations. The theoretical foundation of the study are the communities of practice and the organizational inertia theories. The study indicates that the dynamics of technological capability of cluster organizations’ companies varies regarding three identified communities of practice, namely Participants, Cooperators and Locomotives. The so-called Dead souls (not included in any of the identified communities of practice) did not accumulate technological capability, while the companies classified as Participants increased their technological capability through social learning in cluster organizations provided that the cluster organizations offered comparatively high benefits. Those members of cluster organizations, identified as Cooperators and Locomotives, exhibited relatively high initial technological capability and increased it when the benefits received through social learning in cluster organizations were aligned with their technological trajectories. The study adds to the underdeveloped knowledge of cluster organizations by examining their role in enabling social learning that helps cluster firms accumulate technological capability.
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Social perception of technological innovations at sports facilities: justification for financing ‘white elephants’ from public sources? The case of Euro 2012 Stadiums in Poland
- Krystian Zawadzki
The main purpose of the paper is to provide a monetary valuation of social benefits in connection with the hypothetical implementation of technological innovations at four Euro 2012 stadiums in Poland. Not only the construction of the sport’s arenas, but also the ongoing maintenance drain the pockets of Polish taxpayers. At the same time Euro 2012 stadiums remain underused, which familiarize the host cities with the concept of ‘white elephants’. Due to the application of the contingent valuation method (CVM), the social effects obtained by the residents of four Polish cities were linked to proposed technological innovations, which were given appropriate monetary values. The research has proved the importance of technological innovations at the Euro 2012 stadiums in Poland. As a result, the residents of four Polish cities valued the social benefits related to the implementation of these innovations at PLN 70 million (USD 18 million).
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Solar Photovoltaic Energy Optimization and Challenges
- Arsalan Muhammad Soomar
- Abdul Hakeem
- Mustapha Messaoudi
- Piotr Musznicki
- Amjad Iqbal
- Stanisław Czapp
The study paper focuses on solar energy optimization approaches, as well as the obstacles and concerns that come with them. This study discusses the most current advancements in solar power generation devices in order to provide a reference for decision-makers in the field of solar plant construction throughout the world. These technologies are divided into three groups: photovoltaic, thermal, and hybrid (thermal/photovoltaic). As a result, this article begins by outlining the approach that will be employed to undertake this research. Following that, solar energy production methods are researched and their sub-classifications are described in order to establish their resource needs and features. Following that, a detailed conversation is held. Each technology’s environmental and economic performance will be evaluated. Furthermore, a statistical analysis is conducted to emphasize the efficiency and performance of each solar technology, as well as to identify their global rankings in terms of power output. Finally, research trends in the development of solar power plants are presented. The credibility of the Photovoltaic system, types and limitations is the discussion under study system makes use of sun’s energy to generate electricity with the help of varied procedural systems; stand-alone, hybrid or grid charged. Based on this research, it is possible to infer that the primary goals of optimization approaches are to reduce investment, operation and maintenance costs, and emissions in order to improve system dependability. This paper also includes a brief overview of several solar energy optimization problems and issues.
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Solubility of Methane in Water: Some Useful Results for Hydrate Nucleation
- Joanna Grabowska
- Samuel Blazquez
- Eduardo Sanz
- Iván M. Zerón
- Jesús Algaba
- José Manuel Míguez
- Felipe J. Blas
- Carlos Vega
In this paper, the solubility of methane in water along the 400 bar isobar is determined by computer simulations using the TIP4P/Ice force field for water and a simple LJ model for methane. In particular, the solubility of methane in water when in contact with the gas phase and the solubility of methane in water when in contact with the hydrate has been determined. The solubility of methane in a gas–liquid system decreases as temperature increases. The solubility of methane in a hydrate–liquid system increases with temperature. The two curves intersect at a certain temperature that determines the triple point T3 at a certain pressure. We also determined T3 by the three-phase direct coexistence method. The results of both methods agree, and we suggest 295(2) K as the value of T3 for this system. We also analyzed the impact of curvature on the solubility of methane in water. We found that the presence of curvature increases the solubility in both the gas–liquid and hydrate–liquid systems. The change in chemical potential for the formation of hydrate is evaluated along the isobar using two different thermodynamic routes, obtaining good agreement between them. It is shown that the driving force for hydrate nucleation under experimental conditions is higher than that for the formation of pure ice when compared at the same supercooling. We also show that supersaturation (i.e., concentrations above those of the planar interface) increases the driving force for nucleation dramatically. The effect of bubbles can be equivalent to that of an additional supercooling of about 20 K. Having highly supersaturated homogeneous solutions makes possible the spontaneous formation of the hydrate at temperatures as high as 285 K (i.e., 10K below T3). The crucial role of the concentration of methane for hydrate formation is clearly revealed. Nucleation of the hydrate can be either impossible or easy and fast depending on the concentration of methane which seems to play the leading role in the understanding of the kinetics of hydrate formation.
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SOLUTIONS OF THE INTERMEDIATE SUPPORT STRUC- TURES OF THE NORTHERN MARMARA HIGHWAY (ISTAN- BUL’S RING ROAD) IN THE CONTEXT OF SEISMIC ACTIVITY
- Karol Grębowski
- Mikołaj Miśkiewicz
- Krzysztof Wilde
In 2014–2018, as a result of the expansion of the city of Istanbul in Turkey, a project was imple- mented consisting of building a northern ring road, called the Northern Marmara Highway. The concept of the structural design of the ring road’s intermediate supports aims at constructing sup- ports that according to the TURKISH DLH 2008 standard must comply with the design require- ments for the three calculated earthquake insensitivity levels (D1, D2, D3). The article discusses the modelling of plastic hinges in the reinforced concrete intermediate supports using finite elements methods. The Ductility Demand-Capacity method was used to determine the geometrical parame- ters of the cross-section plasticisation zones, their ability to move and rotate, and their ductility. Due to the varied geometry and stiffness of the supports and their non-linear behaviour under dynamic load, this method was concluded to be imperfect. Therefore, an improved algorithm was proposed by determining the main parameters of the plastic hinges depending on the degree of concrete deg- radation according to Lubliner’s assumptions. The new algorithm was used to design the structure of viaducts of the Istanbul Northern Marmara Highway ring road implemented by the authors. The obtained results may help to prevent failures and damage to the viaducts’ supports structure and thus ensure the safety of all users exploiting the objects. Based on the collected results, it was prov- en that the proposed concept of intermediate supports with a variable geometry and stiffness design including the plastic-damage reinforced concrete model, and on the basis of the plastic hinges con- cept, broadens and enriches the issue of analysis of bridge structures exposed to earthquakes.
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Solvent Exchange around Aqueous Zn(II) from Ab Initio Molecular Dynamics Simulations
- Adrian Malinowski
- Maciej Śmiechowski
Hydrated zinc(II) cations, due to their importance in biological systems, are the subject of ongoing research concerning their hydration shell structure and dynamics. Here, ab initio molecular dynamics (AIMD) simulations are used to study solvent exchange events around aqueous Zn2+, for which observation in detail is possible owing to the considerable length of the generated trajectory. While the hexacoordinated Zn(H2O)62+ is the dominant form of Zn(II) in an aqueous solution, there is a non-negligible contribution of the pentacoordinated Zn(H2O)52+ complex which presence is linked to the dissociative solvent exchange events around Zn2+. The pentacoordinated Zn(II) has a much tighter hydration sphere and is characterized by a trigonal bipyramidal structure, in contrast to the usual octahedral symmetry of the hexacoordinated complex. In total, two full exchange events are registered in the analyzed trajectory. AIMD simulations on an adequate length scale thus provide a direct way of studying such solvent exchange events around ions in molecular detail.
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Some accelerationist remarks on Marcuse’s drives theory and his dialectics of civilization
- Andrzej Karalus
Marcuse’s theory of civilization offers a promising Freud-Marx synthesis. His approach, best articulated in Eros and Civilization, aims at a thorough reformulation of the Freudian drive doctrine to render it more historical and concatenate it to the problem of structural violence and the institutionalized (and internalized) mechanism of repression. I claim that the said reformulation provides a cornerstone for Marcuse’s highly idiosyncratic variant of a critical theory, which, according to my interpretation, possesses clear proto-accelerationist undertones. The article offers a concise recapitulation of Marcuse’s “dialectics of civilization” and points at the somewhat surprising close convergences with the accelerationist version of postcapitalism in his reflection on politics, technology, and the role of arts and aesthetic imagination in challenging the affirmative (desublimating) character of culture.
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Some new soliton solutions to the higher dimensional Burger–Huxley and Shallow water waves equation with couple of integration architectonic
- Farrah Ashraf
- Tehsina Javeed
- Romana Ashraf
- Amina Rana
- Ali Akgül
- Shahram Rezapour
- Muhammad Bilal Hafeez
- Marek Krawczuk
In this paper, we retrieve some traveling wave, periodic solutions, bell shaped, rational, kink and anti-kink type and Jacobi elliptic functions of Burger’s equation and Shallow water wave equation with the aid of various integration schemes like improved -expansion scheme and Jacobi elliptic function method respectively. We also present our solutions graphically in various dimensions.
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Sources and composition of chemical pollution in Maritime Antarctica (King George Island), part 1: Sediment and water analysis for PAH sources evaluation in the vicinity of Arctowski station
- Joanna Potapowicz
- Małgorzata Szopińska
- Danuta Szumińska
- Robert Józef Bialik
- Żaneta Polkowska
The paper presents a study regarding the identification of polycyclic aromatic hydrocarbons (PAHs) in fresh waters and surface sediments on the western shore of Admiralty Bay over four sampling seasons from 2017 to 2018. The results were compared to literature data from 2016 to provide a more comprehensive image of the environmental fate of PAHs over the years. The highest value of Σ PAHs was 82.9 ng/L and 445 ng/g dw in water and sediment samples, respectively. The analysis of PAH indicator ratio values showed that pyrogenic or mixed sources contribute to the PAH pollution in Antarctic sediments and water more than does petroleum. The main source is the combustion of biomass (e.g. as a result of fires) and coal, and PAHs are mostly associated with the activity of stations or are transported to a lesser extent by long-range atmospheric transport (LRAT) from South America. The values of the ΣLMW/ΣHMW ratio in sediments indicate that petrogenic sources contribute to PAH contamination, but among the six PAH ratios tested, petrogenic sources were identified as dominant in approximately 17–19% of cases. Lack of coherence in the obtained results confirms the mixed origin of PAHs in the studied samples. Although the differentiation of PAHs sources is still ambiguous, caution is recommended in light of the Antarctic system's evident and rapid response to global and local PAH emissions, and the dependency of accumulation and release cycle processes on weather conditions. A reduction in petrol usage in favour of renewable energy sources, and restriction of tourism are strongly recommended for better preservation of the pristine Antarctic environment.
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Spatiotemporal Assessment of Satellite Image Time Series for Land Cover Classification Using Deep Learning Techniques: A Case Study of Reunion Island, France
- Naik Nitesh Navnath
- Kandasamy Chandrasekaran
- Andrzej Stateczny
- Venkatesan Meenakshi Sundaram
- Prabhavathy Panneer
Current Earth observation systems generate massive amounts of satellite image time series to keep track of geographical areas over time to monitor and identify environmental and climate change. Efficiently analyzing such data remains an unresolved issue in remote sensing. In classifying land cover, utilizing SITS rather than one image might benefit differentiating across classes because of their varied temporal patterns. The aim was to forecast the land cover class of a group of pixels as a multi-class single-label classification problem given their time series gathered using satellite images. In this article, we exploit SITS to assess the capability of several spatial and temporal deep learning models with the proposed architecture. The models implemented are the bidirectional gated recurrent unit (GRU), temporal convolutional neural networks (TCNN), GRU + TCNN, attention on TCNN, and attention of GRU + TCNN. The proposed architecture integrates univariate, multivariate, and pixel coordinates for the Reunion Island’s landcover classification (LCC). the evaluation of the proposed architecture with deep neural networks on the test dataset determined that blending univariate and multivariate with a recurrent neural network and pixel coordinates achieved increased accuracy with higher F1 scores for each class label. The results suggest that the models also performed exceptionally well when executed in a partitioned manner for the LCC task compared to the temporal models. This study demonstrates that using deep learning approaches paired with spatiotemporal SITS data addresses the difficult task of cost-effectively classifying land cover, contributing to a sustainable environment.
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Sperm segmentation and abnormalities detection during the ICSI procedure using machine learning algorithms
- Aleksandra Frączek
- Gabriela Karwowska
- Mateusz Miler
- Joanna Liss
- Anna Węsierska
- Magdalena Mazur-Milecka
(1) About 15-20% of couples struggle with the problem of infertility. 30 to 40% of these cases are caused by abnormalities in the structure and motility of sperm. Sometimes the only possibility for such people is to use the procedure of artificial insemination. CASA systems are used to increase the efficiency of this procedure by selecting the appropriate sperm cell. (2) This paper presents an approach to the sperm classification on the basis of its entire structure analysis, including flagella - often poorly visible and therefore ignored in the CASA systems element. The training of the Mask R-CNN architecture was performed on 2 publicly available and one specially created for this purpose sperm database. A 14-element feature vector was also proposed for the classification of 4 classes of typical head defects (amorphous, normal, tapered and pyriform) by the Support Vector Machine. (3) The sperm head (mAP 94.28%) and the whole flagellum (mAP 90.29%) were successfully detected. However, the flagella segmentation results were significantly lower (50.88%) than that the head segmentation (88.32%). Classification with SVM scored 82% accuracy. (4) Research has shown that segmentation and the use of a simple SVM classifier allow for quite good results in the classification of sperm defects. However, it is important to develop a larger whole sperm database, to improve the segmentation results.
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Spiral Search Grasshopper Features Selection with VGG19-ResNet50 for Remote Sensing Object Detection
- Andrzej Stateczny
- G. Uday Kiran
- G. Bindu
- Kanegonda Ravi Chythanya
- K. Ayyappa Swamy
Remote sensing object detection plays a major role in satellite imaging and is required in various scenarios such as transportation, forestry, and the ocean. Deep learning techniques provide efficient performance in remote sensing object detection. The existing techniques have the limitations of data imbalance, overfitting, and lower efficiency in detecting small objects. This research proposes the spiral search grasshopper (SSG) optimization technique to increase the exploitation in feature selection. Augmentation is applied in input images to generate more images, and this helps to train the model and reduces data imbalance problems. The VGG-19 and ResNet50 model is applied for feature extraction, and this helps to extract deep features to represent objects. The SSG feature selection technique increases the exploitation and select unique features for object detection that helps to overcome the data imbalance and overfitting problem. The SSG feature selection model helps to balance the exploration and exploitation that escape from the local optima trap. The SSG model has 82.45% mAP, the SSD model has 52.6% mAP, and the MPFP-Net model has 80.43% mAP.
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Społeczność akademicka świętuje Tydzień Otwartego Dostępu 2022
- Kamila Kokot-Kanikuła
- Agnieszka Szymik
W dniach 24-30 października 2022 roku odbyła się kolejna odsłona święta Otwartego Dostępu pod hasłem „Otwartość dla sprawiedliwości klimatycznej”. Jak co roku w ostatni pełny tydzień października, Biblioteka Politechniki Gdańskiej zorganizowała dla społeczności akademickiej szereg atrakcji, które miały na celu promowanie idee otwartości wśród naukowców i studentów.
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Spurious Modes in Model Order Reduction in Variational Problems in Electromagnetics
- Valentin De La Rubia
- David Young
- Grzegorz Fotyga
- Michał Mrozowski
In this work, we address an everlasting issue in 2 model order reduction (MOR) in electromagnetics that has 3 remained unnoticed until now. Contrary to what has been 4 previously done, we identify for the very first time spurious 5 modes in MOR for time-harmonic Maxwell’s equations and 6 propose a methodology to remove their negative influence on the 7 reduced order model (ROM) response. These spurious modes 8 have nonzero resonance frequency and may have shown up 9 in the past giving rise to spikes in the frequency response, 10 in effect, deteriorating the accuracy and efficiency of the MOR 11 process. However, they were never characterized as spurious 12 mode contributions, rather they were most likely considered 13 as poor localized approximation issues in the MOR process. 14 When we try to get further physical insights from the ROM, 15 rather than simple frequency domain data, we cannot afford 16 any poorly localized approximation issue, that is, any spurious 17 mode in the band of analysis. Otherwise, these mathematical, 18 but nonphysical, modes will mislead the physical behavior of the 19 device under analysis. A computationally inexpensive variational 20 divergence condition is established to identify spurious modes in 21 the band of analysis, since any physical in-band mode must be 22 divergence-free. In addition, once a spurious mode is identified in 23 the band of analysis, its influence is removed from the ROM by 24 a physics-based coupling strategy. As a result, a robust spurious 25 mode contribution-free MOR in electromagnetics is proposed. 26 Finally, several actual microwave circuits, such as a quad-mode 27 filter and a triple-mode triple-band filter, will illustrate the 28 capabilities and efficiency of the proposed approach.
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Stability investigation of the PCM nanocomposites
- Paulina Boroń
- Maciej Fabrykiewicz
- Janusz Cieśliński
In present study was showed the results of research the stability of nanoPCMs in terms of types and concentrations of surfactant used. For stearic acid has been added PVP or oleic acid in concentrations of 0%, 5% and 10%. Nanoparticles TiO2 and Al-2O3 in concentration of 1% were chosen to be researched in this test. The mixing of nanocomposites has been done in an ultrasonic scrubber in which the samples were placed for 45 mins. The stability was researched through the measurement the changing of temperature over time. The measurements have been done in controlled thermostatic conditions. The results were obtained after clotting the samples from 70°C to 20°C and melting the samples form 20°C to 70°C. The expected results was obtaining plot waveforms with reduced loading time for materials containing surfactants and nanoparticles at their core.
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Stan przedawaryjny oraz sposób naprawy dźwigarów dachowych z drewna klejonego
- Maciej Niedostatkiewicz
- Tomasz Majewski
W artykule przedstawiono opis uszkodzeń konstrukcji dachu sali sportowej, w szczególności drewnianych dźwigarów dachowych z drewna klejonego, które powstały w wyniku popełnionych błędów projektowych oraz wykonawczych. W pracy przedstawiono różne koncepcje naprawy oraz zrealizowane rozwiązanie projektowe wzmocnienia dźwigarów dachowych.
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Stan przedawaryjny oraz sposób naprawy dźwigarów dachowych z drewna lejonego
- Maciej Niedostatkiewicz
- Tomasz Majewski
W artykule przedstawiono opis uszkodzeń konstrukcji dachu sali sportowej w szczególności drewnianych dźwigarów dachowych z drewna klejonego które powstały w wyniku popełnionych błędów projektowych oraz wykonawczych. W pracy przedstawiono różne koncepcje naprawy oraz zrealizowane rozwiązanie projektowe wzmocnienia dźwigarów dachowych.
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Stardust - Investigation of Microbes in the Stratosphere
- Marcin Jasiukowicz
- Bartosz Rybacki
- Mateusz Grzybowski
- Natalia Czortek
- Dawid Rekowski
- Jakub Pawłowski
- Paulina Podpirko
- Kacper Loret
- Dominika Tomaszewska
- Szymon Magrian
- Karol Pelzner
- Remigiusz Galikowski
- Bartosz Rybak
- Beata Krawczyk
The stratospheric microbiome has been investigated several times using the methods of classical microbiology. In this experiment, we have combined them with some novel approaches including whole- metagenome amplification, Maldi TOF mass spectrometry and Sanger DNA sequencing. The results of the experiment may provide the scientists with knowledge about the mechanisms of survivability of microorganisms in stratospheric conditions such as high doses of UV and cosmic radiation, low temperature and low humidity. The preliminary results have shown that the stratosphere is very poor in microorganisms in comparison to the regular, tropospheric air. Also the investigation is very difficult due to many problems with both small amounts of biological material and the high risk of contamination. However, contamination is possible to control, and modern methods of biotechnology help in the research of low quantities of material. The experiment was launched from Esrange Space Center in September 2021, onboard BEXUS 30 balloon mission conducted within the REXUS/BEXUS programme.
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Starodruki w cyfrowej odsłonie – Biblioteka PG zrealizowała projekt Ministerstwa Edukacji i Nauki
- Anna Sobolewska
- Kamila Kokot-Kanikuła
Biblioteka Politechniki Gdańskiej ukończyła właśnie realizację projektu „Społeczna Odpowiedzialność Nauki” w ramach modułu „Wsparcie dla bibliotek naukowych”. Projekt realizowany był w ramach konkursu ogłoszonego w 2019 roku przez Ministerstwo Edukacji i Nauki.
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State tax policy and reform tools as a risk of running a business. Case study based on Polski Ład – Polish tax reform
- Ewa Łączek-Tarazewicz
- Jarosław Wróblewski
- Piotr Kasprzak
- Gabriela Golawska-Witkowska
The aim of the article is to describe and present the Polish tax reform introduced at the beginning of 2022. Tax changes introduced in Poland had a strong impact on the risk of running a business in Poland because in their assumption they directly changed the rules of running a business. Due to the pace of the introduced changes, as well as the scope of the reform, the new tax law was subject to numerous criticisms of taxpayers in Poland (especially entrepreneurs). Although in its initial assumptions, the program of changes entitled The Polish Deal (“Polski Ład) was aimed not only at changing the tax law, but also introducing numerous investment programs as a response to the COVID-19 post-pandemic reality. The article attempts to assess the risk associated with the change of tax law from the point of view of enterprises from the SME sector, and presents the most important assumptions related to the change in the law, as well as the consequences of their introduction.