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Search results for: microwave solvothermal synthesis
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Application of commercial microwave links (CMLs) attenuation for quantitative estimation of precipitation
PublicationPrecipitation estimation models are typically sourced by rain gauges, weather radars and satellite observations. A relatively new technique of precipitation estimation relies on the network of Commercial Microwave Links (CMLs) employed for cellular communication networks: the rain-inducted attenuation in the links enables the precipitation estimation. In the paper, it is analysed to what extent the precipitation derived from CML...
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Rapid multi-criterial design of microwave components with robustness analysis by means of knowledge-based surrogates
PublicationManufacturing tolerances and uncertainties concerning material parameters, e.g., operating conditions or substrate permittivity are detrimental to characteristics of microwave components. The knowledge of relations between acceptable parameter deviations (not leading to violation of design specifications) and the nominal performance (not considering uncertainties), and is therefore indispensable. This paper proposes a multi-objective...
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Novel and Efficient Synthesis of Unsymmetrical Trisulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical trisulfides under mild conditions in very good yields. The designed method is based on the straightforward preparation of 1-[(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)trisulfanyl]dodecane from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane, sulfur dichloride (SCl2) and dodecane-1-thiol. The unsymmetrical trisulfides can...
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SEM micrographs of 3D printed CB-PLA samples topography after microwave treatment
Open Research DataThis dataset contains the electrochemical studies on microwave-activated carbon-black doped polylactic acid 3D printed electrodes.
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Expedited Multi-Objective Design Optimization of Miniaturized Microwave Structures Using Physics-Based Surrogates
PublicationIn this paper, a methodology for fast multi-objective design optimization of compact microwave circuits is presented. Our approach exploits an equivalent circuit model of the structure under consideration, corrected through implicit and frequency space mapping, then optimized by a multi-objective evolutionary algorithm. The correction/optimization of the surrogate is iterated by design space confinement and segmentation based on...
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SYNTHESIS AND PROPERTIES OF OLIGOMERS WITH HYDROXY END-GROUPS
PublicationMethods of oligomers (polymers) with hydroxy end-groups obtaining are examined. The synthesis of hydroxy-containing oligomers based on epoxy resins is of special attention. The molecules of mentioned oligomers apart from free primary and secondary hydroxy groups contain epoxy, peroxy, carboxy or acrylic groups.
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Synthesis and polymerisation techniques of molecularly imprinted polymers
PublicationMolecularly Imprinted Polymers (MIPs) are materials that has been processed using the molecular imprinting technique which permit to obtain well-defined three-dimensional cavities, with affinity to a template molecule, in the polymer matrix. Technology involves three strategies, i.e., covalent, non-covalent and semi-covalent approach, but the most popular is non-covalent approach. The most important components for the synthesis...
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The possibility of use by-products for synthesis of emulsifiers
PublicationIn the last years the interest in use of materials originated from natural sources, e.g. vegetables to produce attractive products still grows. According to that, also the synthesis of these products should be adequate to the green chemistry requirements. The typical example observed in recent years focuses on utlization of bioglycerol - the by - product of global biodiesel manufacturing. The still growing production of biodiesel...
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Preparation of exfoliated graphite by microwave irradiation
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Microwave-assisted boration of potato starch
PublicationZiarnistą skrobię ziemniaczaną boranowano za pomocą kwasu borowego i dziesięciowodnego tetraboranu sodu (boraksu) w reakcji wspomaganej mikrofalami. Określono wpływ stosunku substratów oraz czasu trwania i mocy naświetlania na stopień estryfikacji (DE) produktów. Maksymalna wartość DE w próbkach skrobi boranowanej kwasem wyniosła 0,27, a boranowanej boraksem 0,18. Ustalono, że chociaż zmodyfikowana skrobia, o strukturze estrów...
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Cost-Efficient Two-Level Modeling of Microwave Passives Using Feature-Based Surrogates and Domain Confinement
PublicationA variety of surrogate modelling techniques has been utilized in high-frequency design over the last two decades. Yet, the curse of dimensionality still poses a serious challenge in setting up re-liable design-ready surrogates of modern microwave components. The difficulty of the model-ing task is only aggravated by nonlinearity of circuit responses. Consequently, constructing a practically usable surrogate model, valid across...
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Uncertainty Quantification of Additive Manufacturing Post-Fabrication Tuning of Resonator-Based Microwave Sensors
PublicationReconfigurability, especially in terms of the ability of adjusting the operating frequency, has become an important prerequisite in the design of modern microwave components and systems. It is also pertinent to microwave sensors developed for a variety of applications such as characterization of material properties of solids or liquids. This paper discusses uncertainty quantification of additive-manufacturing-based post-fabrication...
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Łukasz Kulas dr hab. inż.
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Computationally efficient two-objective optimization of compact microwave couplers through corrected domain patching
PublicationFinding an acceptable compromise between various objectives is a necessity in the design of contemporary microwave components and circuits. A primary reason is that most objectives are at least partially conflicting. For compact microwave structures, the design trade-offs are normally related to the circuit size and its electrical performance. In order to obtain comprehensive information about the best possible trade-offs, multi-objective...
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Rapid Yield Optimization of Miniaturized Microwave Passives by Response Features and Variable-Fidelity EM Simulations
PublicationThe operation of high-frequency devices, including microwave passive components, can be impaired by fabrication tolerances but also incomplete knowledge concerning operating conditions (temperature, input power levels) and material parameters (e.g., substrate permittivity). Although the accuracy of manufacturing processes is always limited, the effects of parameter deviations can be accounted for in advance at the design phase...
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Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method
PublicationMolten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0995Ca0005NbO4 and BaCe09−xZrxY01O3....
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Morphology control through the synthesis of metal-organic frameworks
PublicationDesignable morphology and predictable properties are the most challenging goals in material engineering. Features such as shape, size, porosity, agglomeration ratio significantly affect the final properties of metal- organic frameworks (MOFs) and can be regulated throughout synthesis parameters but require a deep under- standing of the mechanisms of MOFs formation. Herein, we systematically summarize the effects of the indi- vidual...
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Włodzimierz Zieniutycz prof. dr hab. inż.
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Residue-Pole Methods for Variability Analysis of S-parameters of Microwave Devices with 3D FEM and Mesh Deformation
PublicationThis paper presents a new approach for variability analysis of microwave devices with a high dimension of uncertain parameters. The proposed technique is based on modeling an approximation of system by its poles and residues using several modeling methods, including ordinary kriging, Adaptive Polynomial Chaos (APCE), and Support Vector Machine Regression (SVM). The computational cost is compared with the traditional Monte-Carlo...
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Reduced-Cost Microwave Design Closure by Multi-Resolution EM Simulations and Knowledge-Based Model Management
PublicationParameter adjustment through numerical optimization has become a commonplace of contemporary microwave engineering. Although circuit theory methods are ubiquitous in the development of microwave components, the initial designs obtained with such tools have to be further tuned to improve the system performance. This is particularly pertinent to miniaturized structures, where the cross-coupling effects cannot be adequately accounted...
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Unraveling a novel microwave strategy to fabricate exposed {001}/{101} facets anatase nanocrystals: Potential for use to the elimination of environmentally toxic metronidazole waste
PublicationThis study present a novel microwave strategy to fabricate highly active anatase particles, exposing {101} and {001} facets. Microwave treatment time was shown to determine the growth of crystals in a certain direction. To the best of our knowledge, it is the first report revealing that the contact time of TiO2 crystals with fluorine ions during the microwave process affects the formed morphology, in particular exposed facets ratio....
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Variable-fidelity response feature surrogates for accelerated statistical analysis and yield estimation of compact microwave components
PublicationAccounting for manufacturing tolerances is an essential part of a reliable microwave design process. Yet, quantification of geometry and/or material parameter uncertainties is challenging at the level of full-wave electromagnetic (EM) simulation models. This is due to inherently high cost of EM analysis and massive simulations necessary to conduct the statistical analysis. Here, a low-cost and accurate yield estimation procedure...
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Amino Acid Based Antimicrobial Agents – Synthesis and Properties
PublicationStructures of several dozen of known antibacterial, antifungal or antiprotozoal agents are based on the amino acid scaffold. In most of them, the amino acid skeleton is of a crucial importance for their antimicrobial activity, since very often they are structural analogs of amino acid intermediates of different microbial biosynthetic pathways. Particularly, some aminophosphonate or aminoboronate analogs of protein amino acids are...
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Implementation of multi-operand addition in FPGA using high-level synthesis
PublicationThe paper presents the results of high-level synthesis (HLS) of multi-operand adders in FPGA using the Vivado Xilinx environment. The aim was to estimate the hardware amount and latency of adders described in C-code. The main task of the presented experiments was to compare the implementations of the carry-save adder (CSA) type multi-operand adders obtained as the effect of the HLS synthesis and those based on the basic component...
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DDQ-mediated synthesis of functionalized unsymmetrical disulfanes
PublicationWe developed a simple and efficient method for the synthesis of functionalized unsymmetrical disulfanes under mild conditions in good yields. The designed method is based on the reaction of bis(5,5- dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)disulfane with thiols in the presence of 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). The developedmethod allows the preparation of unsymmetrical disulfanes bearing additional hydroxy, carboxy,...
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Low-cost multi-objective design of compact microwave structures using domain patching
PublicationA good compromise between size and electrical performance is an important design consideration for compact microwave structures. Comprehensive information about size/performance trade-offs can be obtained through multi-objective optimization. Due to considerable electromagnetic (EM) cross-couplings in highly compressed layouts, the design process has to be conducted at the level of high-fidelity EM analysis which is computationally...
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Improved Design Closure of Compact Microwave Circuits by Means of Performance Requirement Adaptation
PublicationNumerical optimization procedures have been widely used in the design of microwave components and systems. Most often, optimization algorithms are applied at the later stages of the design process to tune the geometry and/or material parameter values. To ensure sufficient accuracy, parameter adjustment is realized at the level of full-wave electromagnetic (EM) analysis, which creates perhaps the most important bottleneck due to...
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Efficient Method for the Synthesis of Functionalized Basic Maleimides
PublicationA three-step procedure involving Diels-Alder condensation of maleic anhydride with furane, formation of N-substituted imide upon reaction with appropriate diamine and a final retro Diels-Alder regeneration of the maleic carbon-carbon double bond is proposed for an unequivocal synthesis of N-substituted basic maleimides. The novel method is characterized by mild reaction conditions, easy work-up, high yields and no need for additional...
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JOURNAL OF MICROWAVE POWER AND ELECTROMAGNETIC ENERGY
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International Journal of Microwave and Wireless Technologies
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IEEE Microwave and Guided Wave Letters
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International Journal of Microwave Science and Technology
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International Journal of Microwave and Optical Technology
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IEEE Microwave and Wireless Technology Letters
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Study of the Effectiveness of Model Order Reduction Algorithms in the Finite Element Method Analysis of Multi-port Microwave Structures
PublicationThe purpose of this paper is to investigate the effectiveness of model order reduction algorithms in finite element method analysis of multi-port microwave structures. Consideration is given to state of the art algorithms, i.e. compact reduced-basis method (CRBM), second-order Arnoldi method for passive-order reduction (SAPOR), reduced-basis methods (RBM) and subspace-splitting moment-matching MOR (SSMM-MOR)
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Analysis-by-synthesis paradigm evolved into a new concept
PublicationThis work aims at showing how the well-known analysis-by-synthesis paradigm has recently been evolved into a new concept. However, in contrast to the original idea stating that the created sound should not fail to pass the foolproof synthesis test, the recent development is a consequence of the need to create new data. Deep learning models are greedy algorithms requiring a vast amount of data that, in addition, should be correctly...
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Bacteriophages as Factories for Eu2O3 Nanoparticle Synthesis
PublicationThe use of phage display to identify peptides with an ability to bind and synthesize Eu2O3 nanoparticles is demonstrated in this report. This is the first report of modified phages specifically binding a lanthanide. The peptides exposed on virions revealed very strong binding to Eu2O3 nanoparticles and the ability to catalyze Eu2O3 nanoparticles’ formation from Eu(OH)3 and Eu(NO3)3 solutions. The luminescence emission spectrum...
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Fast multi-objective design optimization of microwave and antenna structures using data-driven surrogates and domain segmentation
PublicationPurpose Strategies and algorithms for expedited design optimization of microwave and antenna structures in multi-objective setup are investigated. Design/methodology/approach Formulation of the multi-objective design problem oriented towards execution of the population-based metaheuristic algorithm within the segmented search space is investigated. Described algorithmic framework exploit variable fidelity modeling, physics- and...
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Low-power microwave-induced fabrication of functionalised few-layer black phosphorus electrodes: A novel route towards Haemophilus Influenzae pathogen biosensing devices
PublicationIn this paper, various passivation schemes were applied at few-layer black phosphorus (FLBP) to achieve covalent functionalisation with 4-azidobenzoic acid, improving its electrochemical response intended for analytical and biosensing applications. The thermal and microwave assisted modification procedures in toluene and dime-thylformamide resulted in high reversibility of reactions on functionalised FLBP using a ferricyanide/ferrocya-nide...
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Efficient Synthesis of Functionalized Unsymmetrical Dialkyl Trisulfanes
PublicationWe have developed a convenient method for the synthesis of functionalized unsymmetrical dialkyl trisulfanes under mild conditions in very good yields. The designed method is based on the reaction of (5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)-disulfanyl derivatives with alkyl disulfanyl anions generated in situ from S-acetyl disulfanyl derivatives and sodium methoxide. The developed method allows for the preparation of...
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An NO2 sensor based on WO3 thin films for automotive applications in the microwave frequency range
PublicationA microwave system dedicated to the detection of nitrogen dioxide in the harsh environment of the Norway highways is proposed. An optimized transmission line type of sensor coated with a tungsten trioxide thin film that changes its electrical properties under NO2 gas exposure is developed. The sensors' response (S) is given in °/GHz and it is calculated based on wideband measurements. The advantage of wideband measurements in comparison...
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Hydrothermal synthesis of vanadium ammonium compounds – the crucial role of the pressure
PublicationDue to the structural diversity and chemical activity, vanadium oxides and their derivatives are continuingly in the great interest of scientist. In a large family of vanadium compounds, one of the most interesting are ammonium vanadates (with the general formula (NH4)xVyOz). They have received much attention because of their promising application as cathode material in mono- and multivalent-ion batteries [1]. Hydrothermal synthesis...
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Improved-Efficacy Optimization of Compact Microwave Passives by Means of Frequency-Related Regularization
PublicationElectromagnetic (EM)-driven optimization is an important part of microwave design, especially for miniaturized components where the cross-coupling effects in tightly arranged layouts make traditional (e.g., equivalent network) representations grossly inaccurate. Efficient parameter tuning requires reasonably good initial designs, which are difficult to be rendered for newly developed structures or when re-design for different operating...
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Machine-Learning-Based Global Optimization of Microwave Passives with Variable-Fidelity EM Models and Response Features
PublicationMaximizing microwave passive component performance demands precise parameter tuning, particularly as modern circuits grow increasingly intricate. Yet, achieving this often requires a comprehensive approach due to their complex geometries and miniaturized structures. However, the computational burden of optimizing these components via full-wave electromagnetic (EM) simulations is substantial. EM analysis remains crucial for circuit...
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Cost-Efficient Globalized Parameter Optimization of Microwave Components through Response-Feature Surrogates and Nature-Inspired Metaheuristics
PublicationDesign of contemporary microwave devices predominantly utilizes computational models, including both circuit simulators, and full-wave electromagnetic (EM) evaluation. The latter constitutes the sole generic way of rendering accurate assessment of the system outputs that considers phenomena such as cross-coupling or radiation and dielectric losses. Consequently, for reliability reasons, the final tuning of microwave device parameters...
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Low-cost data-driven modelling of microwave components using domain confinement and PCA-based dimensionality reduction
PublicationFast data-driven surrogate models can be employed as replacements of computationally demanding full-wave electromagnetic simulations to facilitate the microwave design procedures. Unfortunately, practical application of surrogate modelling is often hindered by the curse of dimensionality and/or considerable nonlinearity of the component characteristics. This paper proposes a simple yet reliable approach to cost-efficient modelling...
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Cost-Efficient Multi-Objective Design of Miniaturized Microwave Circuits Using Machine Learning and Artificial Neural Network
PublicationDesigning microwave components involves managing multiple objectives such as center frequencies, impedance matching, and size reduction for miniaturized structures. Traditional multi-objective optimization (MO) approaches heavily rely on computationally expensive population-based methods, especially when exe-cuted with full-wave electromagnetic (EM) analysis to guarantee reliability. This paper introduces a novel and cost-effective...
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An Improved Synthesis of Trisodium (R)-Homocitrate from Citric Acid
PublicationA method of synthesis of trisodium (R)-homocitrate starting from citric acid is reported. The procedure affords the final product of high optical purity with satisfactory yield.
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Virtual Keyboard controlled by eye gaze employing speech synthesis
PublicationThe article presents the speech synthesis integrated into the eye gaze tracking system. This approach can significantly improve the quality of life of physically disabled people who are unable to communicate. The virtual keyboard (QWERTY) is an interface which allows for entering the text for the speech synthesizer. First, this article describes a methodology of determining the fixation point on a computer screen. Then it presents...
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Virtual keyboard controlled by eye gaze employing speech synthesis
PublicationThe article presents the speech synthesis integrated into the eye gaze tracking system. This approach can significantly improve the quality of life of physically disabled people who are unable to communicate. The virtual keyboard (QWERTY) is an interface which allows for entering the text for the speech synthesizer. First, this article describes a methodology of determining the fixation point on a computer screen. Then it presents...