2024 - Repozytorium publikacji - Politechnika Gdańska

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Monitoring Artificial Light Pollution Using a Multispectral Camera
- Anna Bobkowska
- Paweł Tysiąc
- Paweł Burdziakowski
- Jakub Szulwic
2024
Studying the adverse effects of artificial light pollution requires systematic monitoring using various methods. One commonly used technique involves assessing the intensity of light reflected from surfaces with different types of digital cameras at various measurement levels. However, this approach does not always fully capture the characteristics of the light source itself. In our study, we focused on the potential application of a multispectral camera, designed to be mounted on a drone (UAV), to evaluate the spectrum of the light source. We conducted laboratory measurements using the Micasense Dual RedEdge-MX multispectral camera. While recording scenes that included both the light source and reflected light, we also took reference measurements with a spectrometer. Using classical image analysis and mathematical methods, we verified the feasibility of assessing the spectral characteristics of light sources. Based on these results, we developed and tested a concept for monitoring light pollution with drone-mounted multispectral cameras. Our research highlights challenges related to photogrammetry and remote sensing under nighttime conditions. The short shutter-exposure time significantly limits the data needed for generating multispectral orthomosaics. As an alternative, we correlated our data with a conventional nocturnal orthomosaic and performed point-based analysis of bright pixel clusters in the images to evaluate light-source characteristics. Our findings indicate considerable potential for using multispectral cameras to monitor artificial light pollution. By broadening the range of recorded data in narrow spectral bands, we can more accurately assess this phenomenon, which is crucial for identifying sources that may negatively affect the environment, including flora, fauna, and even humans.
Monitoring of Ship Operations in Seaport Areas in the Sustainable Development of Ocean–Land Connections
- Mirosław Gerigk
- Jacek Jachowski
- Zbigniew Burciu
- Teresa Abramowicz-Gerigk
2024 Sustainability
The paper is devoted to underlining the important role of monitoring systems in the sustainable development of seaport areas—sensitive ocean–land connections exposed to the harmful effects of multimodal transport. The study concerns the existing monitoring possibilities of the environmental factors and ship traffic near port infrastructure. The main aim of the study is presenting the example of solutions, supporting the sustainable development of port areas, related to the most dangerous ship maneuvering operations carried out near the berths. An indirect method for measuring loads on the seabed from the propeller and thruster jets during ship berthing and an experimental method for predicting the hydrodynamic forces generated on a moored Panamax-size bulk carrier by a similar vessel passing along in shallow water conditions are described in the context of their implementation in monitoring systems. The cloud-based system—installed in the ferry terminal in the Port of Gdynia and developed for monitoring the flow generated by the ship propellers during maneuvers near the berth and warning about the exceedance of allowable pressure on the quay wall—allows, after a two-year operation, to draw the conclusions related to maintenance planning and has an impact on port sustainability. The discussion presented in the paper underlines the influence of monitoring both the environmental elements and hazardous ship operations on the sustainable development of seaport areas.
Monometallic/Bimetallic Co‐ZIFs Synthesis, Characterization, and Application for Adsorption of SO2 and CO2 in Continuous Flow System
- Sara Sumbal
- Zaheer Aslam
- Umar Irshad
- Sobia Anwar
- Aamir Abbas
- Waqar Ahmad
- Ali Hamza
2024 APPLIED ORGANOMETALLIC CHEMISTRY
Sulfur dioxide is serious ultimatum to human health as well as environment, while carbon dioxide is viewed as one of the primary drivers of the worldwide temperature alteration. Therefore, capturing of these gases is a dynamic research subject attracting much consideration from scientists. Herein, we report synthesis of a series of Co-ZIF and bimetallic M-Co-ZIF adsorbents and application for room temperature adsorption of SO2 and CO2. In this work, the breakthrough curves for the adsorption of sulfur dioxide and carbon dioxide on Co-ZIF and M-Co-ZIF were obtained experimentally and theoretically using a laboratory-scale fixed bed column at room temperature. In this work, the adsorption capacities and breakthrough points for modified bimetallic M-Co-ZIF were found to be relatively higher than parent Co-ZIF. Notably, a high SO2 uptake capacity of 7.1 mmol/g for Zr-Co-ZIF and high CO2 uptake capacity of 69.9 mmol/g for Ni-Co-ZIF were achieved. The parent cobalt and bimetallic ZIF materials were characterized by XRD, FTIR, SEM, and nitrogen physisorption. The XRD results confirm the formation of pure phase highly crystalline ZIF materials while BET analysis suggests high surface area of prepared adsorbents. Finally, the results of dynamic adsorption combined with characterization show great potential for preparation of bimetallic ZIF adsorbents for effective SO2 and CO2 adsorption.
Monte Carlo simulations of the fracture resistance of an asphalt pavement layer
- Łukasz Smakosz
- Cezary Szydłowski
- Jarosław Górski
2024 CONSTRUCTION AND BUILDING MATERIALS
The purpose of the proposed numerical model is to analyze the cracking of the wearing course in a pavement overlay, assuming a pre-existing crack that passes through the binding layer and base. The computations employed the author's simulation-based Monte Carlo material model, which describes the failure process of a Semi-Circular Bend (SCB) specimen during standard laboratory testing of asphalt concrete. A key feature of this model is the incorporation of the random nature of material parameters, allowing for the simulation of result dispersion when analyzing a sufficiently large population of samples. The proposed FEM model and obtained material data were directly applied to the numerical analysis of the pavement structure. The comprehensive computational algorithm allows for a random description of the load that induces crack propagation in the pavement wearing course, leading to the creation of a histogram that defines the range of failure load dispersion. Such supporting calculations can assist in optimizing asphalt mix design and, in the future, may allow for the estimation of pavement structure reliability.
Monte-Carlo Modeling of Optical Sensors for Postoperative Free Flap Monitoring
- Paulina Stadnik
- Ignacy Rogoń
- Mariusz Kaczmarek
2024 Pełny tekst
This work aims to develop a numerical tissue model and implement software to simulate photon propagation using the Monte Carlo method to determine design guidelines for a physical measurement system. C++ was used for the simulation program, and Python as a programming environment to create an interface that allows the user to customize individual simulation elements, allowing for increased accuracy and flexibility when simulating photon movement. This allows the user to customize the simulation to their specific requirements, ensuring the results are as accurate and reliable as possible. It also models the detector to determine if a given photon is in the desired location. The program simulates the propagation of light from a normal illumination medium with anisotropic scattering and records the escape of photons on the upper surface. The simulation also takes into account absorption and scattering coefficients for a given wavelength, and data regarding these parameters are read from a .csv file. The variance reduction technique is used to improve the efficiency of the simulation. The user interface allows users to define their own parameters, such as wavelength, anisotropy coefficient, refractive index, and layer thickness. In this paper, we simulate four photodiodes and different distances between the source and detector to determine the most suitable model for designing a physical sensor.
More than just a beer – Brewers' spent grain, spent hops, and spent yeast as potential functional fillers for polymer composites
- Aleksander Hejna
- Mateusz Barczewski
- Paulina Kosmela
- Joanna Aniśko
- Joanna Szulc
- Katarzyna Skórczewska
- Adam Piasecki
- Tairong Kuang
2024 WASTE MANAGEMENT
Beer is among the most popular beverages in the world, with the production distributed uniformly between the biggest continents, so the utilization of brewing by-products is essential on a global scale. Among their potential recipients, the plastics industry offers extensive range of potential products. Herein, the presented study investigated the application of currently underutilized solid brewing by-products (brewers' spent grain, spent hops, spent yeast) as fillers for highly-filled poly(ε-caprolactone)-based composites, providing the first direct connection between spent hops or spent yeast and the polymer composites. Comprehensive by-product characterization revealed differences in chemical composition. The elemental C:O ratio, protein content, and Trolox equivalent antioxidant capacity varied from 1.40 to 1.89, 12.9 to 32.4 wt%, and 2.41 to 10.24 mg/g, respectively, which was mirrored in the composites' structure and performance. Morphological analysis pointed to the composition-driven hydrophilicity gap limiting interfacial adhesion for high shares of brewers' spent grain and spent hops, due to high hydrophilicity induced by carbohydrate content. Phytochemicals and other components of applied by-products stimulated composites' oxidative resistance, shifting oxidation onset temperature from 261 °C for matrix over 360 °C for high spent yeast shares. Simultaneously, spent yeast also provided compatibilizing effects for poly(ε-caprolactone)-based composites, reducing complex viscosity compared to other fillers and indicating its highest affinity to poly(ε-caprolactone)due to the lowest hydrophilicity gap. The presented results indicate that the proper selection of brewing by-products and adjustment of their shares creates an exciting possibility of engineering composites' structure and performance, which can be transferred to other polymers differing with hydrophilicity.
Morphology and internal structure of small-scale washovers formed in the coastal zone of the semi-enclosed tideless basin, Gulf of Gdańsk, Baltic Sea
- D. Moskalewicz
- F. Bahr
- Łukasz Janowski
- K. Leszczyńska
- P. Sitkiewicz
- M. Słowik
- K. Stattegger
- Paweł Tysiąc
- C. Winter
2024 GEOMORPHOLOGY
This study explores the morphological features and internal structure of small-scale washovers along the southeastern Baltic Sea coast, providing insights into these most widespread yet often neglected deposits in the recent research of geomorphological and sedimentary record of storm surges. A 15-year-long record of morphological changes of the coast was acquired from regional orthophotos to analyse their geometry and spatial characteristics. Sedimentological analyses comprising a description of deposits, grain size and shape analyses, and Ground Penetrating Radar profiling were undertaken to investigate the internal structure of washovers. The formation of washovers appeared to be correlated with the average winter NAO (North Atlantic Oscillation) index. The study revealed different scaling relationships of selected spatial parameters in two coastal settings and extended previously hypothesized relationships of length-area, area-volume, and length-volume. The internal structure of washovers is defined by low-angle planar cross-stratification and horizontal stratification, both disrupted by small troughs. Grain-size data indicated extremely short transport of dune and beach sediments, lately deposited in the form of washovers. The study proves that in all domains, the geomorphological characteristics of washovers are scalable, despite the different coastal settings, and even small-scale washovers fit the existing development models
Most średnicowy w Warszawie. Koncepcja przebudowy
- Krzysztof Żółtowski
- Mikołaj Binczyk
- Przemysław Kalitowski
- Piotr Żółtowski
- Sebastian Chylewski
- Daniel Pełka
- Tomasz Jabłoński
2024 Mosty
Artykuł omawia koncepcję przebudowy Mostu Średnicowego w Warszawie, który, ze względu na zły stan techniczny i nieprzystosowanie do współczesnych wymagań, wymaga rekonstrukcji. Planowana przebudowa obejmuje wykorzystanie istniejących filarów nurtowych oraz wydłużenie mostu, co pozwoli na eliminację wiaduktów nad Wisłostradą i Wybrzeżem Szczecińskim. Przedstawiono trzy warianty konstrukcyjne: kratownicę o zmiennej wysokości, skrzynkowe przęsła blachownicowe oraz konstrukcję nawiązującą do pierwotnego projektu z lat 20. XX wieku. Analizy nośności i detali konstrukcyjnych wykonano przy użyciu zaawansowanych modeli numerycznych w środowisku MES SOFiSTiK. Ostatecznie inwestor wybrał do dalszego projektowania wariant łukowy. Prace projektowe były częścią większej modernizacji całej Linii Średnicowej w Warszawie, której realizacja ma kluczowe znaczenie dla funkcjonowania stołecznego węzła kolejowego.
MSP for port areas – To what extent should we interfere with governance of ports’ waters? Case study of Polish seaports
- Ernest Czermański
- Magdalena Matczak
- Aneta Oniszczuk-Jastrząbek
- Karolina Krośnicka
- Joanna Witkowska
2024 Pełny tekst MARINE POLICY
The EU MSP Directive imposed the requirement to develop plans for all water areas under the jurisdiction of an EU country by the end of March 2021. Poland is the only country in the Baltic Sea Region whose maritime administration has decided to elaborate detailed maritime spatial plans for port waters. The aim of the paper is to draw conclusions from the work carried out so far on the MSP for Polish port water areas. For this purpose, the drafts of the first ever plans for port areas, constituting Poland’s internal marine waters, were considered. The authors analysed planning efforts concerning Polish port water areas in two stages, quantitative and qualitative. The subjects of the analysis were the draft spatial maritime plans, prepared or in preparation, for three selected ports – Gdańsk, Szczecin and Elbląg. These study cases were chosen to represent the best variety of approaches (they were elaborated by different planning companies, having very different planning backgrounds) and were the basis for evaluating the solutions proposed in the draft plans in terms of possible interpretations of the plan’s provisions. The paper raises such questions as: What kind of functions (uses) occur while elaborating the maritime spatial plan of the port’s waters?; How are the functions distinguished within the ports’ plans interpreted by planers originating from different environments and having different types of planning experience?; How could the process of maritime spatial planning for port waters be coordinated between port authorities, maritime administration, and municipal authorities?
Multi-agent strategies for selected network problems
- Robert Ostrowski
2024
The work contains results regarding two problems posed to a group of mobile entities, called agents, and a survey of fields of research from which these problems originate. First, in the heterogeneous graph searching problem, the agents, also called searchers, are asked to find a fugitive in a graph with edges accessible only to specific types of agents. The rules of the edge searching problem are augmented by introducing labels for the edges of the graph and agents. We provide an example with 3 distinct labels which shows the problem to be non-monotone. The heterogeneous tree searching problem is proved to be NP-Hard. Moreover, it remains NP-Complete even when restricted to monotone strategies. Additionally, an example of a case when the problem admits a polynomial algorithm is provided. In the second problem the agents are asked to complete gossiping in a tree network. The network is an edge-weighted tree and the data can only spread by being carried by agents themselves. In order to traverse an edge, an agent needs to spend energy from its battery, and agents can exchange energy whenever they meet. The bulk of the work consists of a proof that an optimal gossiping strategy can be composed of an optimal convergcast strategy followed by a broadcast strategy. We show that k agents in a network of n nodes can solve this problem in O(k2n2) time.
Multi-Analytical Techniques for the Study of Burial Clothes of Polish King Sigismund III Vasa (1566–1633) and His Wife Constance Habsburg (1588–1631)
- Magdalena Śliwka-Kaszyńska
- Maria Cybulska
- Anna Drążkowska
- Sławomir Kuberski
- Jakub Karczewski
- Anna Marzec
- Przemysław Rybiński
2024 Pełny tekst MOLECULES
The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESIMS/ MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.
Multi-channel radio-over-fiber communication systems through modulation instability phenomenon
- Rasul Azizpour
- Hassan Zakeri
- Gholamreza Moradi
- Mohammad Alibakhshikenari
- Francisco Falcone
- Bo Liu
- Tayeb Dendini
- Imko Park
- Sławomir Kozieł
- Ernesto Limiti
2024 Pełny tekst IEEE Photonics Journal
Recent advancements in Radio-over-Fiber (RoF) technology have positioned it as a promising solution for highcapacity wireless communications. This paper explores novel applications of RoF systems in enhancing phased array antenna (PAA) performance for multi-channel wireless communication applications through the modulation instability (MI) phenomenon. Utilizing fibers experiencing MI with varying group velocity dispersions (β2) of -20, -11.3, -3.2, and -2 ps2/km, the RoF system achieves operational flexibility across distinct central frequencies of 12, 16, 30, and 38 GHz, respectively. This approach represents a significant advancement in wireless communication technology, leveraging MI gain and an MI-based control system architecture to enhance performance across diverse frequency bands. The study investigates the impact of MI on modulation efficiency, presenting experimental results validating the feasibility and effectiveness of the proposed approach. The maximum MI gain by employing a 30 km fiber under MI is 18 dB, experimentally. Further optimization, achieved by increasing the fiber length to 45 km and adjusting nonlinear parameters and input power, demonstrates a remarkable MI gain of 38.1 dB. MIbased true time delay (TTD) techniques also address beam squint challenges, enhancing beamforming capabilities. The findings suggest that integrating MI into RoF systems holds excellent potential for improving wireless communication capabilities with reduced costs and space requirements compared to conventional methods. This research contributes to the growing body of knowledge in the field of RoF systems and offers insights into their practical applications in modern wireless communication networks.
Multi-factor fuzzy sets decision system forecasting consumer insolvency risk
- Tomasz Korol
2024 Decision
The objective of this study is to develop a multi-factor decision system predicting insolvency risk for natural persons with the use of fuzzy sets. Considering that the financial situation of households is affected by various endogenous and exogenous factors, the main assumption of this study is that the system for predicting financial difficulties should not be limited to the use of only a few financial variables concerning consumers, but also include variables describing the environment. The author proposes a system consisting of three different forecasting models that connect the macroeconomic and microeconomic environments. It monitors the economic situation of households by also identifying those environmental variables, which may directly, or indirectly, endanger the consumer, such as unemployment rate (job market situation), inflation and interest rates, exchange rates, or economic situation in the country (GDP growth rate, the dynamics of retail sales, etc.). Moreover, the created multi-factor tool is in the form of a flexible application that can be easily adapted to changing economic conditions. Another unique feature of the study is the proposed use of newly developed ratios in household finance, similar to that in financial ratio analysis, which is commonly used in corporate finance. The proposed ratios demonstrated high predictive abilities. The paper also identifies the predictive capabilities of selected macroeconomic variables from the perspective of their impact on the risk of consumer insolvency. The research relies on four samples consisting of a total of 2,400 consumers from Taiwan and Poland. The author created three forecasting models separately for the South-East Asian and Central European regions, and two multi-factor systems, each consisting of 1260 decision rules. The findings clearly showed that a multi-factor system is a significantly more effective method compared to single forecasting models.
Multi-GPU UNRES for scalable coarse-grained simulations of very large protein systems
- Krzysztof Ocetkiewicz
- Cezary Czaplewski
- Henryk Krawczyk
- Agnieszka Lipska
- Adam Liwo
- Jerzy Proficz
- Adam K. Sieradzan
- Paweł Czarnul
2024 COMPUTER PHYSICS COMMUNICATIONS
Graphical Processor Units (GPUs) are nowadays widely used in all-atom molecular simulations because of the advantage of efficient partitioning of atom pairs between the kernels to compute the contributions to energy and forces, thus enabling the treatment of very large systems. Extension of time- and size-scale of computations is also sought through the development of coarse-grained (CG) models, in which atoms are merged into extended interaction sites. Implementation of CG codes on the GPUs, particularly the multiple-GPU platforms is, however, a challenge due to more complicated potentials and removing the explicit solvent, forcing developers to do interaction- rather than space-domain decomposition. In this paper, we propose a design of a multi-GPU coarse-grained simulator and report the implementation of the heavily coarse-grained physics-based UNited RESidue (UNRES) model of polypeptide chains. By moving all computations to GPUs and keeping the communication with CPUs to a minimum, we managed to achieve almost 5-fold speed-up with 8 A100 GPU accelerators for systems with over 200,000 amino-acid residues, this result making UNRES the best scalable coarse-grained software and enabling us to do laboratory-time millisecond-scale simulations of such cell components as tubulin within days of wall-clock time.
Multi-GPU-powered UNRES package for physics-based coarse-grained simulations of structure, dynamics, and thermodynamics of protein systems at biological size- and timescales
- Cezary Czaplewski
- Paweł Czarnul
- Henryk Krawczyk
- Agnieszka Lipska
- Emilia Lubecka
- Krzysztof Ocetkiewicz
- Jerzy Proficz
- Adam Sieradzan
- Rafał Ślusarz
- Józef Liwo
2024 BIOPHYSICAL JOURNAL
Coarse-grained models are nowadays extensively used in biomolecular simulations owing to the tremendous extension of size- and time-scale of simulations. The physics-based UNRES (UNited RESidue) model of proteins developed in our laboratory has only two interaction sites per amino-acid residue (united peptide groups and united side chains) and implicit solvent. However, owing to rigorous physics-based derivation, which enabled us to embed atomic details in the energy function, it is able to model the structures, dynamics, and thermodynamics of protein systems at good accuracy without ancillary information from structural databases. The UNRES package is an implementation of the UNRES model and uses Langevin molecular dynamics and its extensions for conformational search. It can be applied in both unrestrained simulations and those with restraints from experimental data or bioinformatics models. The package has been heavily optimized for memory and parallel performance using the message passing interface (MPI) and OpenMP libraries. Further, a GPU (graphical processor unit) and a well-scalable multiple-GPU version have been developed, thus enabling us to reach about 1 ms laboratory time in 1 day of computations for a chunk of tubulin comprising 234,260 amino-acid residues. In this communication the recent developments of the UNRES package will be presented and illustrated with appropriate examples including the simulations of (i) the dynamics of human norovirus variants, (ii) the dynamics of kinesin binding to tubulin, (iii) the conversion of thermal energy into net rotational motion by selected molecular rotatory motors, (iv) prediction of the structures of proteins and protein assemblies in recent CASP/CAPRI experiments and (iv) determination of protein structures at coarse-grained level using ambiguous NMR data. The optimized UNRES package is available from www.unres.pl and https://projects.task.gda.pl/eurohpcpl-public/unres.
Multi-instrument analysis of L-band amplitude scintillation observed over the Eastern Arabian Peninsula
- Abdollah Masoud Darya
- Muhammad Mubasshir Shaikh
- Grzegorz Nykiel
- Essam Ghamry
- Ilias Fernini
2024 ADVANCES IN SPACE RESEARCH
The study of scintillation-causing ionospheric irregularities is important to mitigate their effects on satellite communications. It is also important due to the spatial and temporal variability of these irregularities, given that their characteristics differ from one region to another. This study investigates the spatial and temporal characteristics of L1 amplitude scintillation-causing ionospheric irregularities over the Eastern Arabian Peninsula during the ascending phase of solar cycle 25 (years 2020–2023). The temporal occurrences of weak and strong scintillation were separated by sunset, with weak scintillation observed predominantly pre-sunset during the winter solstice and strong scintillation observed mainly post-sunset during the autumnal equinox. Strong scintillation was much more pronounced in 2023 compared to the other three years, indicating a strong influence of solar activity. Spatially, weak-scintillation-causing irregularities exhibited a wide distribution in azimuth and elevation, while strong-scintillation-causing irregularities were concentrated southwards. The combined analysis of S4 and rate of total electron content index (ROTI) suggested that small-scale ionospheric irregularities were present in both pre- and post-sunset periods, while large-scale irregularities were only seen during the post-sunset period. Furthermore, the presence of southward traveling ionospheric disturbances (TIDs) during the 2023 autumnal equinox was confirmed with the total electron content anomaly (dTEC), while the Ionospheric Bubble Index (IBI) provided by the Swarm mission was unable to confirm the presence of equatorial plasma bubbles during the same period. Observations from the FORMOSAT-7/COSMIC-2 mission indicated that strong-scintillation-causing irregularities were more prevalent under the F2-layer peak, while the weak-scintillation-causing irregularities were mostly observed at the E-layer, F2-layer, and above the F2-layer. This study aims to contribute insights into the behavior of scintillation-causing ionospheric irregularities in the region, with implications for future research during the peak of the 25th solar cycle.
Multilayer coatings based on cerium oxide and manganese cobaltite spinel for Crofer22APU SOC interconnects
- Elisa Zanchi
- Justyna Ignaczak
- Grzegorz Cempura
- Sebastian Molin
- Aldo R. Boccaccini
- Federico Smeacetto
2024 MATERIALS LETTERS
The current state of the art steel interconnect coating materials are based on critical raw material - Co-oxide spinels. Replacing Co-oxide spinels with alternative, abundant materials can reduce the dependence on the critical raw materials. Cobalt-free coatings with the general formula Mn2-xCuFexO4, where x = 0, 0.1, 0.3, were electrophoretically deposited on a ferritic stainless-steel support and evaluated. Prior to deposition, the powders were prepared by a soft chemistry process and studied in terms of crystallographic phase analysis, electrical conductivity, thermal expansion, and sinterability behaviour. Coated steel samples were oxidised in an air atmosphere at 750 °C for 3000 h. In parallel, a state-of-the-art MnCo2O4 spinel oxide was tested as a reference. The coatings and oxide scale microstructures of the surfaces and cross-sections were examined by XRD, and SEM-EDX. TEM-EDX, XRF, and micro-XRD were also performed on the cross-section lamellae. The electrical properties of the steel-coating system were evaluated by Area Specific Resistance measurement. The results confirm that Mn–Cu–Fe oxides exhibit higher conductivity and lower TEC than Mn–Co oxide. Based on the obtained results, it might be concluded that the proposed coatings are a promising alternative to coatings that contain cobalt.
Multimodal analysis of traction forces and the temperature dynamics of living cells with a diamond-embedded substrate
- Tomasz Kołodziej
- Mariusz Mrózek
- Saravanan Sengottuvel
- Maciej Głowacki
- Mateusz Ficek
- Wojciech Gawlik
- Zenon Rajfur
- Adam M. Wojciechowski
2024 Pełny tekst Biomedical Optics Express
Cells and tissues are constantly exposed to chemical and physical signals that regulate physiological and pathological processes. This study explores the integration of two biophysical methods: traction force microscopy (TFM) and optically detected magnetic resonance (ODMR) to concurrently assess cellular traction forces and the local relative temperature. We present a novel elastic substrate with embedded nitrogen-vacancy microdiamonds that facilitate ODMR-TFM measurements. Optimization efforts focused on minimizing sample illumination and experiment duration to mitigate biological perturbations. Our hybrid ODMR-TFM technique yields TFM maps and achieves approximately 1 K precision in relative temperature measurements. Our setup employs a simple wide-field fluorescence microscope with standard components, demonstrating the feasibility of the proposed technique in life science laboratories. By elucidating the physical aspects of cellular behavior beyond the existing methods, this approach opens avenues for a deeper understanding of cellular processes and may inspire the development of diverse biomedical applications.
Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
- Tadele Ayana
- Marcin Morawiec
- Lelisa Wogi
2024 Pełny tekst IEEE Access
Based on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed controller. The machine state variables are involved in flux generation and speed control rules. The performance of the proposed control strategy is formally studied by simulation and demonstrated through experiments. The technique exhibits fast convergence to the optimal flux level, reduces computational resource requirements, and enhances torque production and loss minimization accuracy. It eliminates the excessive flux demands compared to open-loop steady-state values, which will necessitate greater current levels without justification, resulting in an increased power dissipated. This optimum flux level minimizes induction motor losses for efficiency increments.
Multi-Taper-Based Automatic Correction of Non-Anechoic Antenna Measurements
- Mariusz Dzwonkowski
- Vorya Waladi
- Adrian Bekasiewicz
2024 Pełny tekst METROLOGIA
Prototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed in non-anechoic conditions and then refined using appropriate correction algorithms. Unfortunately, the existing post-processing methods suffer from multiple challenges that include manual setup of parameters as well as validation of performance in idealized conditions. In this communication, a multi-taper-based framework for correction of antenna characteristics obtained in non-anechoic environments has been proposed. The algorithm augments one-shot measurements of the structure under test in order to extract the line-of-sight responses while attenuating the interferences pertinent to multi-path propagation and noise from external sources of radiation. The performance of the proposed correction routine has been demonstrated in two test sites using a geometrically small Vivaldi radiator and validated against state-of-the-art techniques from the literature. The uncertainty budget for the measurements performed using the approach amounts to 0.26 dB, which is low given challenging propagation conditions considered for experiments.