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Modern control strategy of bidirectional DAB converter with consideration of control nonlinearity
- Serafin Bachman
- Marek Turzyński
- Marek Jasiński
2024 Pełny tekst Przegląd Elektrotechniczny
This paper focuses on the control strategy for modern universal bidirectional Dual Active Bridge (DAB) converters for microgrid systems. An analysis of the converter equations was carried out, and typical problems related to the influence of dead time on the system operation were discussed. A closed control loop was developed, then tested by simulation and on a laboratory stand.
Modification of gradient HPLC method for determination of small molecules' affinity to human serum albumin under column safety conditions: Robustness and chemometrics study
- Mateusz Woziński
- Katarzyna Greber
- Monika Pastewska
- Piotr Kolasiński
- Weronika Hewelt-Belka
- Beata Żołnowska
- Jarosław Sławiński
- Daniel Szulczyk
- Wiesław Sawicki
- Krzesimir Ciura
2024 JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
In the early stages of drug discovery, beyond the biological activity screening, determining the physicochemical properties that affect the distribution of molecules in the human body is an essential step. Plasma protein binding (PPB) is one of the most important investigated endpoints. Nevertheless, the methodology for measuring %PPB is significantly less popular and standardized than other physicochemical properties, like lipophilicity. Here, we proposed how to modify protocols presented by Valko into column safety conditions and evaluated their robustness using fractional factorial design. For robustness testing, four factors were selected: column temperature, mobile phase flow rate, maximum isopropanol concentration in the mobile phase, and buffer pH. Elaborate methods have been applied for the analysis of HSA affinity for three groups of antibiotic-oriented substances that vary in chemical structure: fluoroquinolones, sulfonamides, and tetrazole derivatives. Furthermore, based on the reversed-phase chromatography the workflow of pilot studies was proposed to select molecules that have high affinity to HSA and can not be eluted from the HSA column using the concentration of organic modifier recommended by the column manufacturer
Modified sliding mode control for seamless integration of P.V. energy in A.C. grid
- Shoaib Shaikh
- Arsalan Muhammad Soomar
- Kifayat Ullah
- Emad A.A. Ismail
- Fuad A. Awwad
- Muhammad Kamran
- Piotr Musznicki
- Syed Hadi Hussain Shah
2024 Energy Reports
Solar energy is a potentially abundant and reliable source of renewable energy. While it can undoubtedly increase grid reliability and efficiency, the inverted voltage generated from PV. sources may introduce distortion into the AC. grid. The proposed control mechanism, modified sliding mode control (MSMC), can seamlessly integrate the inverter output generated by obtaining DC. voltage from the boost converter linked with the PV. output. This research confirms the validity of the proposed method by comparing its results with a similar system that is only integrated through filters and with a system with a P.I. control technique. The simulation proves the effectiveness of seamlessly integrating the Photovoltaic (PV) source into the AC. grid.
Molecular Design Using Selected Concentration Effects in Optically Activated Fluorescent Matrices
- Aneta Lewkowicz
- Katarzyna Walczewska-Szewc
- Martyna Czarnomska
- Emilia Gruszczyńska
- Mattia Pierpaoli
- Robert Bogdanowicz
- Zygmunt Gryczynski
2024 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Molecular physics plays a pivotal role in various fields, including medicine, pharmaceuticals, and broader industrial applications. This study aims to enhance the methods for producing specific optically active materials with distinct spectroscopic properties at the molecular level, which are crucial for these sectors, while prioritizing human safety in both production and application. Forensic science, a significant socio-economic field, often employs hazardous substances in analyzing friction ridges on porous surfaces, posing safety concerns. In response, we formulated novel, non-toxic procedures for examining paper evidence, particularly thermal papers. Our laboratory model utilizes a polyvinyl alcohol polymer as a rigid matrix to emulate the thermal paper’s environment, enabling precise control over the spectroscopic characteristics of 1,8-diazafluoro-9-one (DFO). We identified and analyzed the cyclodimer 1,8-diazafluoren-9-one (DAK DFO), which is a non-toxic and biocompatible alternative for revealing forensic marks. The reagents used to preserve fingerprints were optimized for their effectiveness and stability. Using stationary absorption and emission spectroscopy, along with time-resolved emission studies, we verified the spectroscopic attributes of the new structures under deliberate aggregation conditions. Raman spectroscopy and quantum mechanical computations substantiated the cyclodimer’s configuration. The investigation provides robust scientific endorsement for the novel compound and its structural diversity, influenced by the solvatochromic sensitivity of the DFO precursor. Our approach to monitoring aggregation processes signifies a substantial shift in synthetic research paradigms, leveraging simple chemistry to yield an innovative contribution to forensic science methodologies.
Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment
- Md. Hasibur Rahaman
- Tong Yang
- Zhongyi Zhang
- Wenbo Liu
- Zhongbing Chen
- Jacek Mąkinia
- Jun Zhai
2024 JOURNAL OF ENVIRONMENTAL MANAGEMENT
The organic matter (OM) and nitrogen in Fresh leachate (FL) from waste compression sites pose environmental and health risks. Even though the constructed wetland (CW) can efficiently remove these pollutants, the molecular-level transformations of dissolved OM (DOM) in FL remain uncertain. This study reports the molecular dynamics of DOM and nitrogen removal during FL treatment in CWs. Two lab-scale vertical-flow CW systems were employed: one using only sand as substrates (act as a control, CW-C) and the other employing an equal mixture of manganese ore powder and sand (experimental, CW-M). Over 488 days of operation, CW-M exhibited significantly higher removal rates for chemical oxygen demand (COD), ammonia nitrogen (NH4 +-N), and dissolved organic matter (represented by dissolved organic carbon, DOC) at 98.2 ± 2.5%, 99.2 ± 1.4%, and 97.9 ± 1.9%, respectively, in contrast to CW-C (92.8 ± 6.8%, 77.1 ± 28.1%, and 74.7 ± 9.5%). The three-dimensional fluorescence excitation-emission matrix (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses unveiled that the influent DOM was predominantly composed of readily biodegradable protein-like substances with high carbon content and low unsaturation. Throughout treatment, it led to the degradation of low O/C and high H/C compounds, resulting in the formation of DOM with higher unsaturation and aromaticity, resembling humic-like substances. CW-M showcased a distinct DOM composition, characterized by lower carbon content yet higher unsaturation and aromaticity than CW-C. The study also identified the presence of Gammaproteobacteria, reported as Mn-oxidizing bacteria with significantly higher abundance in the upper and middle layers of CW-M, facilitating manganese cycling and improving DOM removal. Key pathways contributing to DOM removal encompassed adsorption, catalytic oxidation by manganese oxides, and microbial degradation. This study offers novel insights into DOM transformation and removal from FL during CW treatment, which will facilitate better design and enhanced performance.
Molecularly imprinted polymers based on deep eutectic solvents as a greenest materials for selective extraction of emerging contaminants from complex samples
- Mariusz Marć
- Natalia Jatkowska
- Justyna Płotka-Wasylka
- Daniel Gallart-Mateu
- Francesc A. Esteve‐turrillas
- Miguel De la Guardia
2024 TRAC-TRENDS IN ANALYTICAL CHEMISTRY
Some of the reagents applied in the synthesis of molecularly imprinted polymers (MIPs) may impact on health and the environment. Thus, a new generation of promising green chemicals are nowadays introduced and investigated, including deep eutectic solvents (DESs). DESs seems to be a reasonable choice as they are characterized as non-toxic, low cost, easy to prepare and biodegradable chemicals. This review presents the information on imprinted materials prepared using versus polymerization techniques on which DESs were applied as a more green reagents. Paper presents the benefits and roles of DESs application in the synthesis of MIPs and their potential application area such as selective and reversible sorbents/resins in analytes extraction process as well as chromatographic stationary phases. Furthermore, the specific fields of application of new type of DES-based MIPs in environmental, food and biological samples analysis are described and the future remarks in the area of DES-based MIPs are discussed.
Molecularly imprinted polymers for the detection of volatile biomarkers
- Tomasz Wasilewski
- Sinem Orbay
- Nathália F. Brito
- Karol Sikora
- Ana Claudia A. Melo
- Matias E. Melendez
- Bartosz Szulczyński
- Amitav Sanyal
- Wojciech Kamysz
- Jacek Gębicki
2024 Pełny tekst TRAC-TRENDS IN ANALYTICAL CHEMISTRY
In the field of cancer detection, the development of affordable, quick, and user-friendly sensors capable of detecting various cancer biomarkers, including those for lung cancer (LC), holds utmost significance. Sensors are expected to play a crucial role in the early-stage diagnosis of various diseases. Among the range of options, sensors emerge as particularly appealing for the diagnosis of various diseases, owing to their cost-effectiveness, simplicity, and promising analytical performance. There is growing interest in the application of molecularly imprinted polymers (MIPs) as promising recognition elements in gas sensors. MIPs, as a leading technology for sensing analytes where no suitable bioreceptor exists, are commonly used in artificial sensing that can be applied in key fields like early disease diagnostics, based on the detection of volatile biomarkers. There is an extensive demand for early, non-invasive detection of various diseases and for the self-monitoring of health conditions. Detection of biomarkers in point-of-care mode remains challenging and is limited by various factors. Hence, breath analysis has received enormous attention in healthcare due to its relatively low cost, non-invasive sampling method, and rapid detection capabilities. The latest developments in MIP-based sensors and their utility in disease diagnosis through the detection of volatile biomarkers are comprehensively and critically evaluated in this review. Furthermore, the challenges and perspectives of MIP-based sensors are elaborated upon, with a view towards introduction to the market and successful commercialization.
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-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
- Liu Bo
- Tayeb Dendini
- Imko Park
- Sławomir Kozieł
- Ernesto Limiti
2024 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-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.