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Gdańsk University of Technology

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  • Linking optical and electronic properties to photoresponse of heterojunctions based on titania nanotubes and chromium, molybdenum, and tungsten oxides
    • Łukasz Haryński
    • Adrian Olejnik
    • Jakub Karczewski
    • Jacek Ryl
    • Katarzyna Grochowska
    • Katarzyna Siuzdak
    2022 OPTICAL MATERIALS

    The development of photosensitization strategies for titanium dioxide is necessary for the enhancement of its optical and electronic properties towards its application potential in solar photoelectrochemistry. In this work, significant differences in the photosensitizing capability of the 6th group transition metal oxides applied on the surface of titania nanotubes are reported. For the first time, correlations between the experimentally determined Tauc coefficients, sample photoresponse, and ab-initio simulated properties of the heterojunctions are established. Experimental results show undoubtedly that the decoration of TiO2 nanotubes with chromium oxides leads to the enhanced photoresponse, which originates from the interplay of mid-gap states and both direct and indirect nature of the transitions contributing to the optical absorption. The opposite tendency and decrease of photocurrent were found for molybdenum and tungsten oxides which exhibited forbidden nature of dominating transition. Although computations report intraband states in all interfaces, experimentally only chromium oxides contribute to the photocurrent. The uniqueness of this interface lies in the highest density of states in the vicinity of the conduction band and the low energy difference between the direct and indirect transitions of the innate chromium oxide. The obtained results demonstrate that the determination of the Tauc exponent and the nature of optical transition are more reliable experimental predictors of the photoactivity enhancement in the heterojunctions than the value of the band gap.

  • Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb): A Mixed‐Ligand Pathway to New Lanthanide(III) Multifunctional Materials Featuring Nonlinear Optical and Magnetic Anisotropy Properties
    • Ebube E. Oyeka
    • Michał Winiarski
    • Hanna Świątek
    • Wyatt Balliew
    • Colin D. McMillen
    • Mingli Liang
    • Maurice Sorolla II
    • Thao Tran
    2022 Full text ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

    Bottom-up assembly of optically nonlinear and magnetically anisotropic lanthanide materials involving precisely placed spin carriers and optimized metal-ligand coordination offers a potential route to developing electronic architectures for coherent radiation generation and spin-based technologies, but the chemical design historically has been extremely hard to achieve. To address this, we developed a worthwhile avenue for creating new noncentrosymmetric chiral Ln3+ materials Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb) by mixed-ligand design. The materials exhibit phase-matching nonlinear optical responses, elucidating the feasibility of the heteroanionic strategy. Ln2(SeO3)2(SO4)(H2O)2 displays paramagnetic property with strong magnetic anisotropy facilitated by large spin-orbit coupling. This study demonstrates a new chemical pathway for creating previously unknown polar chiral magnets with multiple functionalities.

  • Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
    • Qing-Yun Deng
    • Shun-Peng Zhu
    • Xiaopeng Niu
    • Grzegorz Lesiuk
    • Wojciech Macek
    • Qingyuan Wang
    2022 Full text INTERNATIONAL JOURNAL OF FATIGUE

    Engineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have attracted increasing attentions. In this study, for distinguishing the effects of different load paths on fatigue life, a simple and applicable method to quantify the non-proportionality is defined, which comprehensively considers the influence of loadings on all material planes. A new equivalent strain damage parameter based on critical plane is proposed in this study. Specifically, to quantify the effect of non-proportional loading on fatigue damage, a non-proportional degree of loading on the generalized plane is developed. Coupling with the existing non-proportional coefficient, a novel fatigue damage parameter is derived by combining a non-proportional factor. Experimental data of 304 stainless steel, sintered porous iron and CuZn37 brass are utilized for model validation and comparison. Fatigue lives with different load paths are evaluated respectively. In comparison with the Fatemi-Socie (FS), Chen and Itoh models, proposed method more effectively evaluate the multiaxial fatigue life of materials under non-proportional loadings.

  • Local variability in snow concentrations of chlorinated persistent organic pollutants as a source of large uncertainty in interpreting spatial patterns at all scales
    • Filip Pawlak
    • Krystyna Koziol
    • Klaudia Kosek
    • Żaneta Polkowska
    2022 Full text JOURNAL OF ENVIRONMENTAL QUALITY

    Single point sampling, a widespread practice in snow studies in remote areas, due to logistical constraints, can present an unquantified error to the final study results. The low concentrations of studied chemicals, such as chlorinated persistent organic pollutants, contribute to the uncertainty. We conducted a field experiment in the Arctic to estimate the error stemming from differences in the composition of snow at short distances (1–3 m), including 13 single organochlorine pesticides and 6 polychlorinated biphenyls, thus providing the most detailed published dataset on the subject. We contrasted this variability with the uncertainty at larger spatial scales, both within one valley (regional scale, this study) and as described in the worldwide literature. The range of values for the coefficient of variation for local samples was 20–58% for single organochlorine pesticides (OCPs) and 33–54% for polychlorinated biphenyls (PCBs), and for regional samples it was 21–69% for OCPs and 65–93% for PCBs. We suggest that, to observe the actual changes in the concentration of selected compounds in snow, they should vary at the level of 40–60%, depending on the compound in question. The uncertainty margin remains much smaller than the current discrepancy between observation data and atmospheric deposition models considering snow, deeming field data on snow concentrations a useful ground-truthing dataset. However, field observations on spatial differences at all scales need to be interpreted with caution, and the dataset provided here on the local sampling uncertainty helps define the margins of such interpretations.

  • Locally sculptured modification of the electrochemical response of conductive poly(lactic acid) 3D prints by femtosecond laser processing
    • Mateusz Cieślik
    • Mirosław Sawczak
    • Rafał Jendrzejewski
    • Joanna Celej
    • Wojciech Nogala
    • Jacek Ryl
    2022 Full text ELECTROCHIMICA ACTA

    This manuscript presents an approach to sculpture high electrochemical activity of the 3D printed electrodes with poly(lactic acid) (PLA) matrix and carbon black (CB) filler by femtosecond laser (FSL) ablation. CB-PLA utility for electrochemical applications depends on a surface modification aiming to remove the PLA and uncover the conductive CB. We have discussed how laser pulse energy is critical for such an activation process. The best performance was obtained for 4.1 J cm−2, while scanning electron microscopy (SEM) shows only partial evaporation of PLA at lower energy densities. Next, we have confirmed the efficiency of locally sculptured CB-PLA surface activation by FSL treatment, obtaining high linearity between electrochemically active surface and FSL-treated surface from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies. The electrode's efficient sculpturing of stripes 0.2 mm in width was confirmed with electrochemical microscopy (SECM). Finally, by using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy, we confirmed no significant oxidation of the CB filler after FSL treatment. We revealed significant differences with ablation by longer nanosecond laser pulses, where significant heat transferred to the electrode surface contributed to partial melting and re-solidification of the PLA, negatively influencing the activation efficiency.

  • Lokalizowanie terminala użytkownika z użyciem interfejsu NB-IoT
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Sadowski
    2022 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    W artykule przedstawiono metodę estymacji położenia terminala użytkownika korzystając z sygnałów okazjonalnych nadawanych w łączu w dół w interfejsie NB-IoT. Zweryfikowano praktyczną zdolność estymacji położenia na testowym obszarze korzystając z sygnałów wzorcowych o zmiennej wartości stosunku sygnału do szumu oraz z różnym emulowanym profilem kanału radiowego. Dodatkowo przedstawiono metodę umożliwiającą zwięk-szenie dokładności estymacji położenia terminala bez konieczności zwiększania częstotliwości próbkowania sygnału radiowego

  • Long-Term GNSS Tropospheric Parameters for the Tropics (2001-2018) Derived from Selected IGS Stations
    • Zofia Baldysz
    • Grzegorz Nykiel
    • Mariusz Figurski
    2022 Full text

    This paper describes dataset “Tropospheric parameters derived from selected IGS stations in the tropics for the years 2001-2018” contains GNSS-derived zenith tropospheric delay (ZTD), a posteriori corrected zenith wet delay (ZWD), and precipitable water vapour (PWV) time series. These troposphere-related data were estimated for the Jan 2001 – Dec 2018 period for 43 International GNSS Service (IGS) stations located across the global tropics. As one coherent strategy for the processing of the GNSS observations was adopted, the dataset is a robust source of long-term, homogeneous tropospheric time series, which can be used in meteorological and climate-related studies. It enables the examination of moisture patterns on numerous time scales, including seasonal and interannual variability.

  • Long-Term Measurement of Physiological Parameters – Child Dataset
    • Małgorzata Szczerska
    2022 Full text

    The dataset titled “Long-term measurement of physiological parameters – child is one dataset” of the bigger series named Long-term measurement of physiological parameters. The dataset contains physiological parameter measurements such as skin temperature and resistance, blood pulse, as well as the stress detection marker, which can have a value of 0 when there is no stress detected or 1 when stress appeared. Additionally, the dataset contains information about the value of the device battery charge. The measurements were conducted for a long period of 120 minutes.

  • Long-term operating conditions for different sorption materials to capture phosphate from domestic wastewater
    • Andrzej Jucherski
    • Andrzej Walczowski
    • Piotr Bugajski
    • Krzysztof Jóźwiakowski
    • Joanna Rodziewicz
    • Wojciech Janczukowicz
    • Shubiao Wu
    • Magda Kasprzyk
    • Magdalena Gajewska
    • Artur Mielcarek
    2022 Full text Sustainable Materials and Technologies

    This paper presents the results of a study on the possibility of applying various configured filters filled with a mixture of Rockfos® and Leca® material for the effective capture of phosphate from domestic wastewater. The tests were carried out for two years at two wastewater flow rates (20 and 40 L/day) in three pairs of filtration columns with a volume of filter material equal to 20 liters each. Columns 1A and 1B were filled only with Rockfos®. Columns 2A and 2B contained Rockfos® and two 5-cm layers of Leca®. Columns 3A and 3B were filled with Rockfos® and a 10% addition of Leca®. A high phosphate removal efficiency was obtained at a level of 93.2 – 94.9% for all columns tested at a flow rate of 20 L/day with a retention time of 12 h. After 250 days of the experiment, the efficiency of phosphate removal decreased significantly, which was associated with a drop in the temperature of the inflowing wastewater (<10°C). The alkaline characteristic (11–12 pH) of the filter material promoted the removal of phosphate from the wastewater. The pH value of the treated wastewater gradually decreased from pH 12 on the first days of an experiment to pH below 9.0 after about 300 days of operation. Studies showed that Rockfos® material can be used successfully to capture phosphate from wastewater for the sustainable development of rural areas in the circular economy. When designing and building phosphate removal filters, it is recommended to use 1 m3 Rockfos® with the addition of Leca® in 1 m3/day of wastewater inflow.

  • Long-Term Stability of Benzodiazepines and Z-Hypnotic Drugs in Blood Samples Stored at Varying Temperatures
    • Laura Banaszkiewicz
    • Mateusz Woźniak
    • Ewa Domagalska
    • Michal Kaliszan
    • Agata Kot-Wasik
    2022 JOURNAL OF ANALYTICAL TOXICOLOGY

    Benzodiazepines (BZDs) and Z-drugs are among the most commonly prescribed pharmaceuticals in the world and are considered standard care for various mental illnesses and for treatment of sleeping and anxiety disorders, alcohol withdrawal, muscle spasms and epilepsy. Some BZDs are not allowed as pharmaceuticals in many countries, and they are used as "designer benzodiazepines" (DBZDs). All these compounds are typically screened in routine toxicological analyses for forensic purposes. Knowledge of time-dependent decreases in drug concentrations during storage or transport of samples is of considerable significance and allows forensic toxicologists to achieve reliable data, proper interpretation and high-quality results. The aim of this study was to evaluate changes in the amounts of selected BZDs, DBZDs and Z-drugs in blood samples stored at various temperatures. The study involved BZDs (19), DBZDs (3) and Z-drugs (2) spiked into blank blood. Subsequently, the blood samples were stored at various temperatures (room temperature, 4°C, -20°C and -80°C) for up to six months. Analyses were performed at 1-2 week intervals using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The stability of compounds were evaluated under four temperature conditions over a 6 month. Some benzodiazepines were stable at all temperatures tested (e.g., diazepam, oxazepam, nordazepam, prazepam) and degradated of only 0-10%. The highest instability was observed for analyte samples kept at room temperature, and the losses in content for some compounds, e.g., lorazepam and chlordiazepoxide, were almost 100%. For other compounds, the stability was clearly different at each tested temperature. To the best of our knowledge, this is one of the first such comprehensive study of the long-term stability of benzodiazepines covering a wide range of different storage temperatures.

  • Low energy inelastic electron scattering from carbon monoxide: II. Excitation of the b3Σ+, j3Σ+, B1Σ+, C1Σ+ and E1Π Rydberg electronic states
    • Mateusz Zawadzki
    • Murtadha Khakoo
    • Ahmad Sakaamini
    • Logan Voorneman
    • Luka Ratkovich
    • Zdeněk Mašín
    • Amar Dora
    • Russ Laher
    • Jonathan Tennyson
    2022 JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

    In this second part of a two part paper (first part: Zawadzki et al (2020 J. Phys. B: At. Mol. Opt. Phys. 53 165201)) we present differential scattering cross sections for excitation of several Rydberg electronic states of carbon monoxide by electron impact. The first part concerned the low-lying valence states of CO. In the present study cross sections are obtained experimentally using low-energy electron energy-loss spectroscopy and theoretically using the R-matrix method. Incident electron energies range from near-threshold of 12.5 eV to 20 eV while the scattering angles range from 20° to 120°. The R-matrix calculations use three distinct close-coupling models and their results are compared to available experimental and theoretical cross sections. The overall comparison leads to significantly improved description of the excitation cross sections for this target.

  • Low-Cost Design Optimization of Microwave Passives Using Multi-Fidelity EM Simulations and Selective Broyden Updates
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    2022 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES

    Geometry parameters of contemporary microwave passives have to be carefully tuned in the final stages of their design process to ensure the best possible performance. For reliability reasons, the tuning has to be to be carried out at the level of full-wave electromagnetic (EM) simulations. This is because traditional modeling methods are incapable of quantifying certain phenomena that may affect operation and performance of these devices, such as cross-coupling effects. As a consequence, the designs yielded with the use of equivalent network models, may only serve as starting points that need further refinement. Unfortunately, simulation-driven numerical optimization is computationally demanding even in the case of local search procedures. Thus, significant research efforts have been aimed toward identifying effective ways of expediting EM-driven optimization procedures, critical from the point of view of cost of design cycles. Among these, one may list the recently proposed multi-fidelity optimization frameworks. Another option for accelerating simulation-driven design procedures are sparse sensitivity updating schemes, where costly gradient estimation through finite-differentiation (FD) is suppressed for selected variables. This work proposes a novel algorithm that capitalizes on both aforementioned mechanisms to reduce the optimization cost of local gradient-based parameter tuning of compact microwave components. In our approach, multi-fidelity optimization is further expedited by replacing expensive FD sensitivity updates with the Broyden formula for selected design variables. Verification using two microwave structures, a branch-line coupler and a power divider, demonstrates average savings of around eighty percent over the basic trust-region (TR) routine, with only minor degradation of the design quality.

  • Low-Cost Quasi-Global Optimization of Expensive Electromagnetic Simulation Models by Inverse Surrogates and Response Features
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    2022 Full text Scientific Reports

    Conceptual design of contemporary high-frequency structures is typically followed by a careful tuning of their parameters, predominantly the geometry ones. The process aims at improving the relevant performance figures, and may be quite expensive. The reason is that conventional design methods, e.g., based on analytical or equivalent network models, often only yield rough initial designs. This is especially the case for miniaturized components featuring considerable electromagnetic (EM) cross couplings, or antenna systems with non-negligible radiator coupling (e.g., MIMO, closely-spaced arrays). For reliability reasons, parametric optimization is carried out using EM simulation tools, which is a time-consuming task. In many cases, designer needs to resort to a global search, especially when handling several objectives and constraints is necessary, or the high-frequency structure under design is overly complex. Combination of both aforementioned factors makes it no longer possible to rely on engineering insight, even to detect a promising region of the design space. Unfortunately, nature-inspired algorithms, commonly employed for solving these tasks typically exhibit significant computational expenditures. This paper proposes a simple yet efficient method for globalized search using a response feature approach and inverse regression surrogates. Owing to less nonlinear dependence of the feature point coordinates on the system variables (as compared to the original responses, e.g., S-parameter frequency characteristics), our methodology permits a rapid identification of the most appropriate regions of the parametric space, and further design tuning by means of local routines. At the same time, the overall optimization cost is comparable to the cost of local procedures. The proposed approach is validated using several high-frequency structures (a dual-band antenna, a microstrip coupler, an impedance matching transformer) optimized under different design scenarios. Global search capability and computational efficiency are demonstrated through comprehensive comparisons with multiple-start local search, as well as particle swarm optimizer, a representative nature-inspired algorithm.

  • Low-Cost Yield-Driven Design of Antenna Structures Using Response-Variability Essential Directions and Parameter Space Reduction
    • Anna Pietrenko-Dąbrowska
    • Sławomir Kozieł
    • Łukasz Gołuński
    2022 Full text Scientific Reports

    Quantifying the effects of fabrication tolerances and uncertainties of other types is fundamental to improve antenna design immunity to limited accuracy of manufacturing procedures and technological spread of material parameters. This is of paramount importance especially for antenna design in the industrial context. Degradation of electrical and field properties due to geometry parameter deviations often manifests itself as, e.g., center frequency shifts or compromised impedance matching. Improving antenna performance at the presence of uncertainties is typically realized through maximization of the fabrication yield. This is normally carried out at the accuracy level of full-wave electromagnetic (EM) analysis, which incurs considerable computational expenses. The involvement of surrogate modeling techniques is the most common approach to alleviating these difficulties, yet conventional modeling methods suffer to a great extent form the curse of dimensionality. This work proposes a technique for low-cost yield optimization of antenna structures. It capitalizes on meticulous definition of the domain of the metamodel constructed for statistical analysis purposes. The domain is spanned by a limited number of essential directions being the most influential in terms of affecting antenna responses in the frequency bands of interest. These directions are determined through an automated decision-making process based on the assessment of the circuit response variability. Our approach permits maintaining small domain volume, which translates into low cost of surrogate model setup, while providing sufficient room for yield improvement. The presented method is validated using three antenna structures and favorably compared to several surrogate-assisted benchmark methods. EM-driven Monte Carlo simulation is also conducted to verify reliability of the yield optimization process.

  • Low-Loss Mechanically Tunable Resonator and Phase Shifters in Groove Gap Waveguide Technology
    • Ali Karami Horestani
    • Zahra Shaterian
    • Michał Mrozowski
    2022 Full text IEEE Access

    This research is focused on the design and realization of high-performance high-power variable phase shifters in groove gap waveguide technology. Specifically, it is shown that the unique characteristic of groove gap waveguides, which is its proper operation without the need for electrical connection between the top and bottom sections of the waveguide, can be used to design mechanically tunable devices. Using the proposed method, a mechanically tunable cavity resonator and phase shifters with a wide range of achievable phase shifts are presented. To validate the concept, a phase shifter with 540 degrees relative phase shift at 15 GHz is designed, fabricated, and measured. Moreover, a multi-layer version of the proposed phase shifter with stationary feed ports and improved performance is presented.

  • Low-Molecular Pyrazine-Based DNA Binders: Physicochemical and Antimicrobial Properties
    • Paulina Mech-warda
    • Giełdoń Artur
    • Anna Kawiak
    • Natalia Maciejewska
    • Mateusz Olszewski
    • Mariusz Makowski
    • Agnieszka Chylewska
    2022 Full text MOLECULES

    Pyrazine and its derivatives are a large group of compounds that exhibit broad biological activity, the changes of which can be easily detected by a substituent effect or a change in the functional group. The present studies combined theoretical research with the density functional theory (DFT) approach (B3LYP/6-311+G**) and experimental (potentiometric and spectrophotometric) analysis for a thorough understanding of the structure of chlorohydrazinopyrazine, its physicochemical and cytotoxic properties, and the site and nature of interaction with DNA. The obtained results indicated that 2-chloro-3-hydrazinopyrazine (2Cl3HP) displayed the highest affinity to DNA. Cytotoxicity studies revealed that the compound did not exhibit toxicity toward human dermal keratinocytes, which supported the potential application of 2Cl3HP in clinical use. The study also attempted to establish the possible equilibria occurring in the aqueous solution and, using both theoretical and experimental methods, clearly showed the hydrophilic nature of the compound. The experimental and theoretical results of the study confirmed the quality of the compound, as well as the appropriateness of the selected set of methods for similar research.

  • Low-Profile Interdigitated UHF RFID Tag Antenna for Metallic Objects
    • Fuad Erman
    • Dalia Mansour
    • Mohammad Kouali
    • Arafat Shabaneh
    • Leifur Leifsson
    • Sławomir Kozieł
    • Effariza Hanafi
    2022 Full text IEEE Access

    This article presents a novel miniature interdigitated ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna that can be placed on metallic objects. The tag structure comprises two horizontal strip lines, each loaded with seven identical open stubs, and an integrated circuit (IC) chip connected directly to the feed lines in the middle of the structure. The perfect match to the IC chip’s impedance is realized by adjusting the length of the loaded open stubs and the spaces between the stubs. Molding the antenna’s geometry can be applied to realize conjugated impedance with any sort of IC chip due to the flexibility of the tag structure. It is fabricated on a Polytetrafluoroethylene (PTFE) slab. Moreover, its structure does not involve any metallic vias or shorting walls, which makes its construction simple and suitable for mass production. The tag of the size of 55.2 mm×44.2 mm×1.5 mm yields a total realized gain of -4.11 dB at the operating frequency while being placed on a 20 cm×20 cm metallic plate. The measured detection distance is 8.14 m on metallic objects. A good match between the measured and simulated results is observed.

  • Low-Voltage Low-Power Filters with Independent ω0 and Q Tuning for Electronic Cochlea Applications
    • Waldemar Jendernalik
    • Jacek Jakusz
    • Grzegorz Blakiewicz
    2022 Full text Electronics

    An acoustic second-order low-pass filter is proposed for filter banks emulating the operation of a human cochlea. By using a special filter structure and an innovative quality (Q)-factor tuning technique, an independent change of the cutoff frequency (ω0) and the Q-factor with unchanged gain at low frequencies is achieved in this filter. The techniques applied result in a simple filter design with low Q-factor sensitivity to component mismatch. These filter features greatly simplify the implementation of the electronic cochlea in CMOS technologies. An exemplary filter bank designed and simulated in an X-FAB 180 nm CMOS process is presented, which consumes 1.25–34.75 nW of power per individual filter when supplied with 0.5 V. The 11-channel filter bank covers a 20–20 kHz band, while the Q-factor of each channel can be tuned from 2 to 40. The simulation-predicted sensitivities of Q and ω0 to process/voltage/temperature (PVT) variations are less than 1%. The input-referred noise is no greater than 22 μVRMS, and the dynamic range is at least 68 dB for all filters in the bank.

  • LTE and NB-IoT Performance Estimation Based on Indicators Measured by the Radio Module
    • Robert Burczyk
    • Agnieszka Czapiewska
    • Małgorzata Gajewska
    • Sławomir Gajewski
    2022 Full text Electronics

    Monitoring the operating parameters of power grids is extremely important for their proper functioning as well as for ensuring the security of the entire infrastructure. As the idea of the Internet of Things becomes more ubiquitous, there are tools for monitoring the state of the complex electrical grid and means to control it. There are also developed new measuring devices and transmission technologies allowing for the transfer of performed measurements from many places to the network management center. However, there are still no devices that act as data concentrators, which would integrate many transmission technologies and protocols in one device, supporting the communication between those different transmission technologies and which would realize edge computing to assist the management center by prioritizing and combining transmitted data. In this article, the authors present a device that meets the above-mentioned requirements. There are presented research results leading to the development of a decision algorithm, called Multilink—ML, dedicated to the presented device. This algorithm enables the selection between LTE and NB-IoT interfaces for packet transmission without the need to burden the communication system with additional transmissions.

  • Machine learning applied to acoustic-based road traffic monitoring
    • Karolina Marciniuk
    • Bożena Kostek
    2022 Full text Procedia Computer Science

    The motivation behind this study lies in adapting acoustic noise monitoring systems for road traffic monitoring for driver’s safety. Such a system should recognize a vehicle type and weather-related pavement conditions based on the audio level measurement. The study presents the effectiveness of the selected machine learning algorithms in acoustic-based road traffic monitoring. Bases of the operation of the acoustic road traffic detector are briefly described. Principles of several machine learning algorithms, data acquisition process, and information about the dataset built are explained. The study is conducted using the audio recordings prepared by the authors, registered in several locations and under different meteorological conditions of the road surface. For each recording containing a single-vehicle passage, a vector of 67 parameters extracted from the audio signal is calculated. Fisher Linear Discriminant Analysis and Regression Analysis, the fastest among algorithms employed, return the following values of accuracy: 0.968 and 0.978, precision: 0.919 and 0.853, recall: 0.882 and 0.974, and F1-score: 0.898 and 0.868 for vehicle type classification. In the case of the road pavement conditions, the obtained metrics are as follows: accuracy of 0.933, precision of 0.898, recall of 0.9, and F1-score of 0.884.

  • Machine learning applied to acoustic-based road traffic monitoring
    • Karolina Marciniuk
    • Bożena Kostek
    2022 Full text

    The motivation behind this study lies in adapting acoustic noise monitoring systems for road traffic monitoring for driver’s safety. Such a system should recognize a vehicle type and weather-related pavement conditions based on the audio level measurement. The study presents the effectiveness of the selected machine learning algorithms in acoustic-based road traffic monitoring. Bases of the operation of the acoustic road traffic detector are briefly described. Principles of several machine learning algorithms, data acquisition process, information about the dataset built are explained. The study is conducted using the audio recordings prepared by the authors, registered in several locations and different meteorological conditions of the road surface. For each recording containing a single-vehicle passage, a vector of 67 parameters extracted from the audio signal is calculated. Fisher Linear Discriminant Analysis and Regression Analysis, the fastest among algorithms employed, return the following values of accuracy: 0.968 and 0.978, precision: 0.919 and 0.853, recall: 0.882 and 0.974, and F-score: 0.898 and 0.868 for vehicle type classification. In the case of the road pavement conditions, the obtained metrics are as follows: accuracy of 0.933, precision of 0.898, recall of 0.9, and F-score of 0.884.

  • Machine-aided detection of SARS-CoV-2 from complete blood count
    • Barbara Klaudel
    • Aleksander Obuchowski
    • Małgorzata Dąbrowska
    • Kornelia Sałaga-zaleska
    • Zdzisław Kowalczuk
    2022

    The current gold standard for SARS-CoV-2 detection methods lacks the functionality to perform population screening. Complete blood count (CBC) tests are a cost-effective way to reach a wide range of people – e.g. according to the data of the Central Statistical Office of Poland from 2016, there are 3,000 blood diagnostic laboratories in Poland, and 46% of Polish people have at least one CBC test per year. In our work, we show the possibility of machine detection of SARS-CoV-2 virus on the basis of routine blood tests. The role of the model is to facilitate the screening of SARS-CoV-2 in asymptomatic patients or in the incubation phase. Early research suggests that asymptomatic patients with COVID-19 may develop complications of COVID-19 (e.g., a type of lung injury). The solution we propose has an F1 score of 87.37%. We show the difference in the results obtained on Polish and Italian data sets, challenges in cross-country knowledge transfer and the selection of machine learning algorithms. We also show that CBC-based models can be a convenient, cost-effective and accurate method for the detection of SARS-CoV-2, however, such a model requires validation on an external cohort before being put into clinical practice.

  • Magazynowanie ciepła i energia odpadowa
    • Tomasz Minkiewicz
    2022

    Przedstawiono technologie magazynowania ciepła, opisano wybrane konstrukcje magazynów ciepła i ich zasadę działania, zdefiniowano pojęcie energii odpadowej oraz wskazano wybrane urządzenia i układy służące do odzyskiwania energii cieplnej.

  • Magnetic deep eutectic solvents – Fundamentals and applications
    • Patrycja Makoś-Chełstowska
    • Massoud Kaykhaii
    • Justyna Płotka-Wasylka
    • Miguel de la Guardia
    2022 Full text JOURNAL OF MOLECULAR LIQUIDS

    Magnetic deep eutectic solvents (MDES), a relatively new subclass of conventional deep eutectic solvents (DES) containing additional paramagnetic components in their structure. MDES exhibit a strong response toward external magnetic fields, thus they can improve many industrial and analytical applications. In addition, this new group of solvents present unique physicochemical properties that can be easily tuned by selecting the appropriate ingredients for MDES synthesis. Therefore, the reported studies on properties and applications have increased in recent years. This review highlights the structures and mechanism of MDES formation, methods of synthesis, basic physicochemical properties, including melting point/freezing point, decomposition temperature, magnetic susceptibility, dynamic viscosity, density, ionic conductivity surface tension, toxicity, and hydrophobic/hydrophilic character, together with current application in analytical and industrial methods/procedures. Moreover, advantages, limitations, and future perspectives of the application MDES are critically discussed. We hope that this review will inspire many new perspectives and developments in the field of MDES applications.

  • Magnetic nanocomposites for biomedical applications
    • Mina Naghdi
    • Mahsa Ghovvati
    • Navid Rabiee
    • Sepideh Ahmadi
    • Nikzad Abbariki
    • Soheil Sojdeh
    • Amirhossein Ojaghi
    • Mojtaba Bagherzadeh
    • Omid Akhavan
    • Esmaeel Sharifi
    • Mohammad Rabiee
    • Mohammad Saeb
    • Keivan Bolouri
    • Thomas J. Webster
    • Ehsan Nazarzadeh Zare
    • Ali Zarrabi
    2022 ADVANCES IN COLLOID AND INTERFACE SCIENCE

    Tissue engineering and regenerative medicine have solved numerous problems related to the repair and regeneration of damaged organs and tissues arising from aging, illnesses, and injuries. Nanotechnology has further aided tissue regeneration science and has provided outstanding opportunities to help disease diagnosis as well as treat damaged tissues. Based on the most recent findings, magnetic nanostructures (MNSs), in particular, have emerged as promising materials for detecting, directing, and supporting tissue regeneration. There have been many reports concerning the role of these nano-building blocks in the regeneration of both soft and hard tissues, but the subject has not been extensively reviewed. Here, we review, classify, and discuss various synthesis strategies for novel MNSs used in medicine. Advanced applications of magnetic nanocomposites (MG-NCs), specifically magnetic nanostructures, are further systematically reviewed. In addition, the scientific and technical aspects of MG-NC used in medicine are discussed considering the requirements for the field. In summary, this review highlights the numerous opportunities and challenges associated with the use of MG-NCs as smart nanocomposites (NCs) in tissue engineering and regenerative medicine.

  • Magnetic properties of α-KCoPO4 compound with a chiral polar crystal structure
    • Jędrzej Kondek
    • Sandra Szczupaczyńska-Zalewska
    • Michał Winiarski
    2022 Full text JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

    We have obtained polycrystalline samples of a metastable α variant of KCoPO4 by low temperature (350–400 °C) solid state metathesis reaction of potassium oxalate and ammonium cobalt orthophosphate. The material crystallizes in a polar chiral structure (sg. P63, no. 173). Measurements of magnetic properties reveal antiferromagnetic interactions and no ordering observed down to T = 1.9 K, well below the Weiss temperature |Θcw| = 13.9 K.

  • Magnetic Signature Description of Ellipsoid-Shape Vessel Using 3D Multi-Dipole Model Fitted on Cardinal Directions
    • Jarosław Tarnawski
    • Tomasz Rutkowski
    • Mirosław Wołoszyn
    • Adam Cichocki
    • Krystian Buszman
    2022 Full text IEEE Access

    The article presents a continuation of the research on the 3D multi-dipole model applied to the reproduction of magnetic signatures of ferromagnetic objects. The model structure has been modified to improve its flexibility - model parameters determined by optimization can now be located in the cuboid contour representing the object's hull. To stiffen the model, the training dataset was expanded to data collected from all four cardinal directions. The robustness of the modified multi-dipole model was verified with various noise levels applied to the synthetic data. A comprehensive numerical verification of the proposed methodology was performed using only data not involved in determining the modified multi-dipole model parameters: the data from intercardinal directions and from different depth were used for cross-validation. An analysis of the influence of initial conditions on the optimization process was carried out. In addition to the gradient optimization method, an evolutionary strategy was also used. Regularization was carried out to search for effective model parameterization. New verification methods were also applied based on the balance of magnetic moments and on the average width of the fit error interval. The results of the performed experiments have shown high robustness of the modified multi-dipole model, even in the face of high noise in the input data. The most significant advantage of the model is its predictive ability, enabling determination of magnetic signatures in any directions and depths with high accuracy.

  • Magnetically sensitive fiber probe with nitrogen-vacancy center nanodiamonds integrated in a suspended core
    • Adam Filipkowski
    • Mariusz Mrózek
    • Grzegorz Stępniewski
    • Maciej Głowacki
    • Dariusz Pysz
    • Wojciech Gawlik
    • Ryszard Buczyński
    • Mariusz Klimczak
    • Adam M. Wojciechowski
    2022 Full text OPTICS EXPRESS

    Efficient collection of photoluminescence arising from spin dynamics of nitrogen vacancy (NV) centers in diamond is important for practical applications involving precise magnetic field or temperature mapping. These goals may be realized by the integration of nanodiamond particles with optical fibers and volumetric doping of the particles alongside the fiber core. That approach combines the advantages of robust axial fixation of NV diamonds with a direct spatial overlap of their fluorescence with the guided mode of the fiber. We developed a suspended core silicate glass fiber with 750 nm-diameter nanodiamonds located centrally in the 1.5 μm-core cross-section along its axis. The developed fiber probe was tested for its magnetic sensing performance in optically detected magnetic resonance measurements using a 24 cm-long fiber sample, with the NV excitation and fluorescence collection from the far ends of the sample and yielding optical readout contrast of 7% resulting in 0.5 μT·Hz−1/2 magnetic field sensitivity, two orders of magnitude better than in earlier designs. Thanks to its improved fluorescence confinement, the developed probe could find application in magnetic sensing over extended fiber length, magnetic field mapping or gradiometry.

  • Mainstream shortcut N removal modeling current status and perspectives
    • Gamze Kirim
    • Kester Mccullough
    • Thiago Bressani-ribeiro
    • Carlos Domingo-félez
    • Haoran Duan
    • Ahmed Al-omari
    • Haydee Clippeleir De
    • Jose Jimenez
    • Stephanie Klaus
    • Mojooulo Ladipo-obasa
    • Mohammad Javad Mehrani
    • Pusker Regmi
    • Elena Torfs
    • Evelina I. P. Volcke
    • Peter Vanrolleghem A.
    2022 Full text WATER SCIENCE AND TECHNOLOGY

    This work gives an overview of the state-of-the-art in modelling of short-cut processes for nitrogen removal in mainstream wastewater treatment and presents future perspectives for directing research efforts in line with the needs of practice. The modelling status for deammonification (i.e., anammox-based) and nitrite-shunt processes is presented with its challenges and limitations. The importance of mathematical models for considering N2O emissions in the design and operation of short-cut nitrogen removal processes is considered as well. Modelling goals and potential benefits are presented and the needs for new and more advanced approaches are identified. Overall, this contribution presents how existing and future mathematical models can accelerate successful full-scale mainstream short-cut nitrogen removal applications.

  • Managing Unemployment under COVID-19 Conditions (States of Emergency or Crisis)
    • Przemysław Banasik
    • Sylwia Morawska
    • Małgorzata Porada - Rochoń
    • Iga Rudawska
    • Małgorzata Godlewska
    • Barbara Kryk
    • Daria Jaskuła
    • Natalia Skalska
    2022 Full text

    Rising unemployment is one of the consequences of the COVID-19 pandemic in many countries. This, in turn, has forcedpolicymakers to respond immediately with policy tools to minimize unemployment. The purpose of our study is to contribute toempirical knowledge by looking at activities of 40 local government units to counteract unemployment in the cross-border regionon the Polish side. In doing this, our study contributes to the efforts to manage unemployment in times of COVID-19 and othercrisis situations. The results show that most of the rural and rural-urban communes did not undertake diagnostic activities thatwould allow one to identify the economic sectors most affected by changes related to the COVID-19 pandemic, e.g., reduction inthe number of employees, suspension, or liquidation of activities. According to LGUs surveyed, companies operating in rural-urban communes applied much more frequently for support for job protection in connection with the COVID-19 pandemic thancompanies located in rural communes.The COVID-19 pandemic demonstrated the crucial role of LGUs in overcoming its impacts. The empirical results of this study(in-depth interviews) indicate that policy makers should pay more attention to consolidating or strengthening the role of LGUs innational disaster management and provide them with the competencies and resources necessary to deal with emergencies (inparticular, they concern strengthening cooperation and coordination with other levels of government, effective communicationand sharing of good practices also in cross-border areas). It would strengthen decision support systems (DSS) in the regions.

  • Manifesto [Intellectual Output 5] for High-quality Baukultur in the Digital Age
    • Justyna Borucka
    • Annette Boegle
    • Uģis Bratuškins
    • Günther H. Filz
    • Anna Kaczorowska
    • Dorota Kamrowska-Załuska
    • Małgorzata Kostrzewska
    • Olga Popovic Larsen
    • Roode Liias
    • Bartosz Macikowski
    • Karl-Gunner Olsson
    • Emiliya Popova
    • Raido Puust
    • Sandra Treija
    • Lotte Bjerregaard Jensen
    2022

    The aim of the Manifesto is to extract the most important messages of the work on the BuildDigiCraft project and to translate them into a public declaration of views, intentions and policy recommendations directed at the academic, professional and policy-making community responsible for the shaping of the built environment (on local, regional, national and European/international level). With the BuildDigiCraft Manifesto the project partners have created a shared official statement on the future of Baukultur in the Digital Age.

  • Marcinkiewicz Averages of Smooth Orthogonal Projections on Sphere
    • Marcin Bownik
    • Karol Dziedziul
    • Anna Kamont
    2022 Full text JOURNAL OF FOURIER ANALYSIS AND APPLICATIONS

    We construct a single smooth orthogonal projection with desired localization whose average under a group action yields the decomposition of the identity operator. For any full rank lattice \Gamma ⊂ R^d , a smooth projection is localized in a neighborhood of an arbitrary precompact fundamental domain R^d / \Gamma. We also show the existence of a highly localized smooth orthogonal projection, whose Marcinkiewicz average under the action of S O(d), is a multiple of the identity on L^2(S^{d−1}). As an application we construct highly localized continuous Parseval frames on the sphere.

  • Market Regeneration in Line with Sustainable Urban Development
    • Justyna Borucka
    • Piotr Czyż
    • Giorgio Gasco
    • Weronika Mazurkiewicz
    • Dorota Nałęcz
    • Marcin Szczepański
    2022 Full text Sustainability

    This article presents the study of the optimal design solutions for regeneration of marketplaces. It examines the design variants for the revitalisation of the marketplace, in particular, investment in their modernisation in order to find the most optimal model for transforming these public spaces to have a significant impact on the city’s development. The research is a comparative analysis of the implementation of regeneration design models on the marketplace within the Oliwa district of Gdansk (Poland).The data for the case study design models includes analysis based on various optimisation criteria, taking into account the urban and economic aspects of the city landscape when selecting a specific space revitalisation design model. The implementation of regeneration investment includes a number of complex processes that must be sustainable and so require rational social and spatial planning, as well as proper organisation in terms of cost and time.

  • Matematyczny świat wirusów i bakterii
    • Agnieszka Bartłomiejczyk
    2022

    Kiedyś, mówiąc o zastosowaniach matematyki, przychodziła nam na myśl głównie fizyka. Dziś wiemy, że matematyka ma ważne zastosowania również w biologii i medycynie. To, jak szybko rozwijają się bakterie i wirusy oraz jak szybko odpowiada na ich obecność nasz układ odpornościowy, można opisać językiem matematyki. Głównym narzędziem służącym do opisu tempa zmiany interesującej nas wielkości jest pochodna. Dzięki pochodnej możemy przewidzieć wzrost lub spadek liczby zachorowań, np. na grypę czy COVID-19, co pozwala nam na podjęcie skutecznych działań zapobiegających rozwojowi pandemii.

  • Mater-Bi/Brewers’ Spent Grain Biocomposites—Novel Approach to Plant-Based Waste Filler Treatment by Highly Efficient Thermomechanical and Chemical Methods
    • Aleksander Hejna
    • Mateusz Barczewski
    • Paulina Kosmela
    • Olga Mysiukiewicz
    • Paweł Sulima
    • Jerzy Andrzej Przyborowski
    • Daria Kowalkowska-Zedler
    2022 Full text Materials

    Thermoplastic starch (TPS) is a homogenous material prepared from native starch and water or other plasticizers subjected to mixing at a temperature exceeding starch gelatinization temperature. It shows major drawbacks like high moisture sensitivity, poor mechanical properties, and thermal stability. To overcome these drawbacks without significant cost increase, TPS could be blended with bio-based or biodegradable polymers and filled with plant-based fillers, beneficially waste-based, like brewers’ spent grain (BSG), the main brewing by-product. Filler modifications are often required to enhance the compatibility of such composites. Herein, we investigated the impact of BSG thermomechanical and chemical treatments on the structure, physical, thermal, and rheological performance of Mater-Bi-based composites. Thermomechanical modifications enhanced matrix thermal stability under oxidative conditions delaying degradation onset by 33 ◦C. Moreover, BSG enhanced the crystallization of the polybutylene adipate terephthalate (PBAT) fraction of Mater-Bi, potentially improving mechanical properties and shortening processing time. BSG chemical treatment with isophorone diisocyanate improved the processing properties of the composites, expressed by a 33% rise in melt flow index. Depending on the waste filler’s selected treatment, processing, and rheological performance, thermal stability or interfacial adhesion of composites could be enhanced. Moreover, the appearance of the final materials could be adjusted by filler selection.

  • Material characterisation of biaxial glass-fibre non-crimp fabrics as a function of ply orientation, stitch pattern, stitch length and stitch tension
    • Philipp Quenzel
    • Hauke Kröger
    • Boris Manin
    • Khiêm Ngoc Vu
    • Thang X. Duong
    • Thomas Gries
    • Mikhail Itskov
    • Roger Sauer
    2022 Full text JOURNAL OF COMPOSITE MATERIALS

    Due to their high density-specific stiffnesses and strength, fibre reinforced plastic (FRP) composites are particularly interesting for mobility and transport applications. Warp-knitted non-crimp fabrics (NCF) are one possible way to produce such FRP composites. They are advantageous because of their low production costs and the ability to tailor the properties of the textile to the reinforcement and drape requirements of the application. Based on their specific production parameters, their draping properties can vary significantly. Draping simulations are used to predict the forming behaviour without relying on costly and time consuming trial and error experiments. However, these simulations require a broad material dataset to make accurate predictions. Previous studies have investigated the relationships between production parameters and drape behaviour only in isolation for a limited number of material parameters at a time. In this study, a comprehensive material characterisation is carried out. The influence of ply orientation, stitch pattern, stitch length and stitch tension on the tensile and bending properties and the friction, shear and drape behaviour of NCFs are investigated on a meso and macro scale. Furthermore, the inter-ply sliding phenomena in bias extension tests are analysed and the results of bias extension and picture frame tests are compared.

  • Material Design and Optimisation of Electrochemical Li-Ion Storage Properties of Ternary Silicon Oxycarbide/Graphite/Tin Nanocomposites
    • Dominik Knozowski
    • Pradeep Vallachira Warriam Sasikumar
    • Piotr Madajski
    • Gurdial Blugan
    • Maria Gazda
    • Natalia Kovalska
    • Monika Wilamowska-Zawłocka
    2022 Full text Nanomaterials

    In this work, we present the characterization and electrochemical performance of various ternary silicon oxycarbide/graphite/tin (SiOC/C/Sn) nanocomposites as anodes for lithium-ion batteries. In binary SiOC/Sn composites, tin nanoparticles may be produced in situ via carbothermal reduction of SnO2 to metallic Sn, which consumes free carbon from the SiOC ceramic phase, thereby limiting the carbon content in the final ceramic nanocomposite. Therefore, to avoid drawbacks with carbon depletion, we used graphite as a substitute during the synthesis of precursors. The ternary composites were synthesized from liquid precursors and flake graphite using the ultrasound-assisted hydrosilylation method and pyrolysis at 1000 °C in an Ar atmosphere. The role of the graphitic component is to ensure good electric conductivity and the softness of the material, which are crucial for long term stability during alloying–dealloying processes. The presented approach allows us to increase the content of the tin precursor from 40 wt.% to 60 wt.% without losing the electrochemical stability of the final material. The charge/discharge capacity (at 372 mA g−1 current rate) of the tailored SiOC/C/Sn composite is about 100 mAh g−1 higher compared with that of the binary SiOC/Sn composite. The ternary composites, however, are more sensitive to high current rates (above 372 mA g−1) compared to the binary one because of the presence of graphitic carbon.

  • Mathematical Approach to Assess a Human Gait
    • Wiktoria Wojnicz
    • Bartłomiej Zagrodny
    • Michał Ludwicki
    • Jan Awrejcewicz
    2022

    A purpose of the paper was to create a mathematical approach to assess a human gait. The scope of the study was to model a normal gait in the sagittal plane and frontal plane of the body. Applying the Newton-Euler formulation, three multibody biomechanical models were derived to describe single support phase and double support phase of the gait. To model a gait in the sagittal plane the open-close sagittal 6DOF model and the open-close sagittal 7DOF model can be used. To model a gait in the frontal plane the open-close frontal 7DOF model can be applied. Presented multibody models can be used to solve a forward dynamic task or an inverse dynamic task.

  • Mathematical model to assess energy consumption using water inflow-drainage system of iron-ore mines in terms of a stochastic process
    • Oleg Sinchuk
    • Ryszard Strzelecki
    • Igor Sinchuk
    • Теtуаnа Веridzе
    • Vladyslav Fedotov
    • Vladyslav Baranovskyi
    • Kyrylo Budnikov
    2022 Full text Mining of Mineral Deposits

    Purpose is to develop a unified mathematical model to assess energy efficiency of a water inflow-drainage process as the real variant of stochastic method for water pumping from underground workings of iron-ore mines. Methods. The research process was based upon the methods of probability theory as well as stochastic modelling methods. The stochastic function integration has been reduced to summation of its ordinates and further transition to a proper boundary. Findings. A mathematical model of a water inflow-drainage system as a stochastic process has been developed in terms of input parameters of a standard operating iron-ore mine. The abovementioned has made it possible to assess realistically, substantiate, and obtain possibilities for a specific production facility as well as for generalization of the results involving determination of stochastic characteristics of drainage process. Originality. For the first time, a mathematical model of drainage from underground levels of iron-ore mines has been developed as a stochastic process. The process characteristics have been identified relying upon randomness of a water pumping technique. In contrast to the available settings, the new model parameters characterize their dispersion. Possibility to obtain complete characteristics of energy consumption has been obtained: for drainage; for water accumulation volume in underground water collectors; for water pumping from the specified mine depths over the specific period as random processes. A number of drainage features have been analyzed and differentiated being determined with the help of normal law of water accumulation velocity in the underground water collectors in iron-ore mines. Practical implications. In terms of operating iron-ore mine, a generalized drainage mathematical model has been developed as a stochastic process using statistical data concerning water accumulation velocity in the underground water collectors. It has been proved that if the ordinates of water accumulation velocity in the underground water collectors obey the normal distribution law then it is expedient to characterize drainage as a stochastic process. The developed methods, studying drainage as a stochastic process, help expand the research boundaries involving other auxiliary operations performed during underground mining of iron ore raw materials.

  • Mathematical modelling of gasification process of sewage sludge in reactor of negative CO2 emission power plant
    • Paweł Ziółkowski
    • Janusz Badur
    • Halina Pawlak-kruczek
    • Kamil Stasiak
    • Milad Amiri
    • Lukasz Niedzwiecki
    • Krystian Krochmalny
    • Jakub Mularski
    • Paweł Madejski
    • Dariusz Mikielewicz
    2022 Full text ENERGY

    Sewage sludge is a residue of wastewater processing that is biologically active and consists of water,organic matter, including dead and alive pathogens, as well as organic and inorganic contaminants suchas polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Due to the nature of sewage sludge and itspossible influence on human health and wellbeing, it is a subject of various regulations. Currently,sewage sludge is considered as biomass, according to the new Polish act on renewable energy sources ofFebruary 20, 2015 and its novel version of July 19, 2019. This study presents a novel model, along with acomparison with experimental results. The model could be used for sewage sludge gasification modellingfor accurate assessment of the performance of novel concepts bioenergy with carbon capture and storage(BECCS) installations, using sewage sludge as a fuel. The composition of the dry produced gas, deter-mined experimentally, yields: XCO¼0.093, XCO2¼0.264, XCH4¼0.139, XCxHy¼0.035, and XH2¼0.468.Performed modifications to the original Deringer-with-Gumz-modification gasification model allowed toobtain good agreement with the experimental results, reaching XCO¼0.071, XCO2¼0.243, XCH4¼0.139,XC3H8¼0.035, and XH2¼0.512. The main novelty in the formulas of the internal model was due topropane inclusion, which was not found in the literature before. Additionally, sulphur dioxide wasapplied in exchange for other sulphur components presented in the original model. Equilibrium con-stants were adjusted to suit the experimental model. For ease of calculation, the own code was used toiterate multiple temperatures. Included was the energy balance equation that is essential for verification

  • Maxillary sinus aeration analysis using computational fluid dynamics
    • Dmitry Tretiakow
    • Krzysztof Tesch
    • Karolina Markiet
    • Andrzej Skorek
    2022 Full text Scientific Reports

    The maxillary sinus aeration using the computational fluid dynamics (CFD) method based on individual adult patients’ computed tomography (CT) scans were analyzed. The analysis was based on CT images of 4 patients: one with normal nose anatomy and three with nasal septal deviation (NSD) and concha bullosa (CB). The CFD simulation was performed using the Reynolds-Average Simulation approach and turbulence closure based on linear eddy viscosity supplemented with the two-equation k-\(\omega\) SST model. As a result, it was found that the lower part of NSD has the most significant impact on the airflow change within the maxillary sinuses compared to CB and the upper part of NSD. In a healthy nose, the airflow in the sinuses is continuous, while NSD and CB change this flow into pulsatile. Multiple changes in the direction of flow during one respiratory phase were observed. The flow intensity within the maxillary sinus opening is lower on the NSD side. The concept of vorticity measure is introduced to evaluate and compare various patients qualitatively. Typically, the lowest values of such measures are obtained for healthy airways and the highest for pathological changes in the nasal cavity.

  • May Staphylococcus lugdunensis Be an Etiological Factor of Chronic Maxillary Sinuses Infection?
    • Maja Kosecka-Strojek
    • Mariola Wolska-Gębarzewska
    • Adrianna Podbielska-Kubera
    • Alfred Samet
    • Beata Krawczyk
    • Jacek Międzobrodzki
    • Michał Michalik
    2022 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Staphylococcus lugdunensis is an opportunistic pathogen found in the healthy human skin microbiome bacterial community that is able to cause infections of diverse localization, manifestation, and course, including laryngological infections, such as necrotizing sinusitis. Chronic maxillary sinusitis is a disease present in up to one third of European and American populations, and its etiology is not fully described. Within this study, we aimed to characterize 18 S. lugdunensis strains recovered from maxillary sinuses and evaluate them as etiological agents of chronic disease. We performed MLST analysis, the complex analysis of both phenotypic and genetic virulence factors, antibiotic susceptibility profiles, and biofilm formation assay for the detection of biofilm-associated genes. Altogether, S. lugdunensis strains were clustered into eight different STs, and we demonstrated several virulence factors associated with the chronic disease. All tested strains were able to produce biofilm in vitro with numerous strains with a very strong ability, and overall, they were mostly susceptible to antibiotics, although we found resistance to fosfomycin, erythromycin, and clindamycin in several strains. We believe that further in-depth analysis of S. lugdunensis strains from different niches, including the nasal one, should be performed in the future in order to reduce infection rate and broaden the knowledge about this opportunistic pathogen that is gaining attention.

  • Meandry życiowe Henryka Bajduszewskiego
    • Dariusz Świsulski
    2022 Full text Śląskie Wiadomości Elektryczne

    W artykule przedstawiono książkę Henryka Bajduszewskiego „Moje meandry życiowe”. Zawiera ona pamiętniki spisywane przez autora w czasie II wojny światowej w niemieckim wojsku we Francji oraz w wojsku polskim we Włoszech. Pamiętniki te zostały współcześnie uzupełnione o wspomnienia z czasów młodości, a także nauki i pracy po wojnie.

  • Measurement method for capacitive sensors for microcontrollers based on a phase shifter
    • Zbigniew Czaja
    2022 Full text MEASUREMENT

    A complete measurement method dedicated to capacitive sensors has been developed. It includes the development of hardware (an analogue interface circuit for microcontrollers with built-in times/counters and analogue comparators) and software (a measurement procedure and a systematic error calibration (correction) algorithm which is based on a calibration dictionary). The interface circuit consists of a low-pass filter and a phase shifter with a capacitive sensor. A prototype circuit based on a mid-range 8-bit microcontroller has been developed and investigated. We also analysed the relative inaccuracy of a measured capacitance of the sensor and performed experimental research. We obtained the relative errors of capacitance determination < 0.06%, which gives a measurement accuracy < 72 fF for the assumed range of the capacitance (100 pF – 300 pF).

  • Measurement of the Temporal and Spatial Temperature Distribution on the Surface of PVCP Tissue Phantom Illuminated by Laser Dataset
    • Anna Sękowska-Namiotko
    2022 Full text

    The dataset entitled Measurement of the temporal and spatial temperature distribution on the surface of PVCP tissue phantom illuminated by laser was obtained with a laboratory set-up for characterisation of the thermal properties of optical tissue phantoms during laser irradiation. The dataset contains a single image file representing the spatial temperature distribution on the surface of a PVCP tissue phantom. This thermal image was captured at the moment when the temperature reached its maximum value as a result of irradiation with a dermatological laser.

  • Measurements of Dispersed Phase Velocity in Two-Phase Flows in Pipelines Using Gamma-Absorption Technique and Phase of the Cross-Spectral Density Function
    • Robert Hanus
    • Marcin Zych
    • Anna Golijanek-Jędrzejczyk
    2022 Full text ENERGIES

    This paper concerns the application of the gamma radiation absorption method in the measurements of dispersed phase velocity in two-phase flows: liquid–gas flow in a horizontal pipe- line and liquid–solid particles in a vertical pipe. Radiometric sets containing two linear 241Am gamma radiation sources and two NaI(Tl) scintillation detectors were used in the research. Due to the stochastic nature of the signals obtained from the scintillation probes, statistical methods were used for their analysis. The linear average velocity of the dispersed phase transportation was calcu- lated using the phase of the cross-spectral density function of the signals registered by the scintilla- tion detectors. It is shown that in the presented cases, the phase method can be more accurate than the most commonly used classical cross-correlation one.

  • Measurements of Two-phase Flows in Pipelines Using Radioisotopes and Statistical Signal Processing
    • Robert Hanus
    • Marcin Zych
    • Anna Golijanek-Jędrzejczyk
    2022 Full text

    This paper presents an application of radiotracers and gamma absorption method in two-phase flow measurements in pipelines. Two different methods were implemented to analysis of acquired signals. Investigated methods are based on the cross-correlation function and the phase of the cross-spectral density distribution. The examples presented in the article illustrate the application of the radioisotopes to evaluation of liquid-gas flow in a horizontal pipe and liquid-solid particles flow in a vertical pipe.

  • Mechanical and physical assessment of epoxy, mineral, solvent-based, and water-soluble coating materials
    • Ginneth Millan Ramirez
    • Hubert Byliński
    • Maciej Niedostatkiewicz
    2022 Full text Scientific Reports

    This paper assesses the behavior of mineral, epoxy (EP), solvent, and water-soluble coatings when exposed to salt and regular water for 28 days. Also, it evaluates the pull-off adhesion strength of the same coating materials applied to concrete slabs saturated with oil and water and dried with two different processes: air-dried for 28 days and air-dried for 14 days plus 14 days in the oven at 70 °C. Properties such as carbonation, water absorption rate, pull-off adhesion strength were evaluated for all coatings, and tensile strength, Young’s modulus, and elongation percentage were calculated for mineral coatings. According to the results, the EP coating showed the best performance with the highest pull-off adhesion strength (2.55 MPa) and lowest absorption rate, about 0.02 ± 0.002 g/m2 day in saltwater and 0.03 ± 0.002 g/m2 day in regular water. In addition, EP coatings also presented the lowest carbonation rate and the highest suppress ratio. The excellent performance of epoxy coatings is mainly due to their low porosity and the ability to decrease chloride diffusion, making them better than other types of coatings investigated in this study.

  • Mechanical Behavior of Plastic Strips-Reinforced Expansive Soils Stabilized with Waste Marble Dust
    • Shelema Amena
    • Worku Firomsa Kabeta
    2022 Full text Advances in Civil Engineering

    Expansive soil needs to undergo treatment to be used as safe foundation soil for roads and buildings. From an environmental conservation and economical point of view, the usage of agricultural and industrial wastes is the best option. In this study, the effects of utilizing plastic waste and marble waste dust on the engineering properties of expansive soils were examined. Various laboratory tests were carried out on sampled expansive soil by adding 10, 15, and 20% of marble and 0.25, 0.5, and 0.75% of 5 × 8 mm² plastic strips. The laboratory test results showed that there are good enhancements on strength parameters due to the addition of marble dust and plastic strips. With an increase in percentages of marble dust and plastic strips, California Bearing Ratio (CBR) values rise. With the addition of marble dust, unconfined compressive strength (UCS) values increase linearly, while they increase only up to 0.5% with the addition of plastic strips. As the proportions of marble dust and plastic strips increase, the soil’s free swell and CBR swell are decreased significantly. This shows that environmental pollution waste marble dust and plastic strips can be utilized to strengthen the weak subgrade soil and minimize its swelling properties. Therefore, this study found out that the expansive soil treated with polyethylene terephthalate (PET) plastic and marble dust can be used as a subgrade material since it fulfills the minimum requirement needed by standards.

  • Mechanical Properties of Human Stomach Tissue
    • Szymon Grymek
    2022 Full text

    The dataset entitled Determination of mechanical properties of human stomach tissues subjected to uniaxial stretching contains: the length of the sample as a function of the corresponding load (tensile force) and the initial values of the average width and average thickness of the sample. All tests were conducted in a self-developed tensile test machine: PG TissueTester. The dataset allows the coefficients of various models of incompressible and nearly incompressible hyperelastic materials used to model human tissues to be determined.