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Zeta potential, effective diameter and multimodal size distribution in oil/water emulsion
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Effect of surface modification on starch/phospholipid wettability
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Investigation of dialkyldimethylammonium bromides as stabilizers and/or emulsifiers for O/W emulsion
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Electrokinetic properties of n-tetradecane/lecithin solution emulsions
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The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids
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Drying silica-nanofluid droplets
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Effect of different crystalline structures on W/O and O/W/O wax emulsion stability
PublikacjatThe possibility of emulsion stabilization using mineral and vegetable wax particles only (without sur-factant) was investigated. Mineral waxes, paraffin wax and ceresin, and a vegetable wax, carnauba wax,were used. The content of the wax particles and the water to oil proportion were found crucial for thestability of all emulsions. Some emulsions were also produced with a liquid wax (i.e. jojoba oil). Themultiple light scattering...
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The effect of alkyl chain length on synergistic effects in micellization and surface tension reduction in nonionic gemini (S-10) and anionic surfactants mixtures
PublikacjaMixtures of nonionic gemini surfactant S-10 ( α, α'-[2,4,7,9-tetrametyl-5-decyne-4,7-diyl]bis[ω-hydroxy -polioxyetylene] with anionic SRS (sodium alkylsulfates) and SRSO3 (sodium alkylsulfonates) of different alkyl chain length (from 10 to 14 carbon atoms) were investigated. Surface tension measurements were used to find the cmc values and other adsorption parameters. The Clint, Rubingh’s and Rosen theories were applied for evaluation...
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Comprehensive study on graphene hydrogels and aerogels synthesis and their ability of gold nanoparticles adsorption
PublikacjaGraphene hydrogels were prepared by ascorbic acid-assisted gelation of graphene oxide (GO) aqueous suspensions both in acidic and basic conditions. Different mass ratio of ascorbic acid (AA) to GO was used (namely 20:1 and 10:1). In order to eliminate the influence of AA on the final structure of hydrogels, samples without AA were prepared by a hydrothermal gelation of GO in an autoclave. An in-depth structural characterization...
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Capping ligand initiated CuInS2 quantum dots decoration on, ZnIn2S4 microspheres surface under different alkalinity levels resulting in different hydrogen evolution performance
PublikacjaSurface distribution of quantum dots (QDs) at the semiconductor matrix caused by synthesis condition (e.g. pH of solution during coupling) could lead to different photocatalytic activity. Thus, achieving an optimal covering of semiconductor matrix by QDs has been challenging. Herein, the influence of the alkalinity level of aqueous decoration medium for the coupling of mercaptoundecanoic acid (MUA) capped CuInS2 quantum dots (CIS)...
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Nonlinear electrical properties of glass-ceramics nanocomposites containing ferroelectric nanocrystallites of Bi2VO5.5
PublikacjaNonlinear A.C. impedance measurements were conducted in the 50BiV-50SrBAlO nanocomposite as a function of frequency, temperature and A.C. voltage. This material is ferroelectric below temperature of 730 K, and above 730 K is a good ion-conductor. For this nanocomposite a low A.C. voltage of 1 V rms is enough to observe high nonlinearities. The origin of these nonlinear effects depends on the temperature and frequency. In the high...
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A Geometrically Simple Compact Wideband Circularly Polarized Antenna
PublikacjaA compact broadband wide-slot circular polarization (CP) antenna is proposed. An inverted L-shape parasitic strip at the open end of a microstrip line extension and a slot modification is applied to attain wideband CP. The advantage of this technique is simplicity which makes it readily re-designable for different frequency bands. To demonstrate the concept, three designs working at different frequencies are obtained. The redesign...
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Independent dynamics of slow, intermediate, and fast intracranial EEG spectral activities during human memory formation
PublikacjaA wide spectrum of brain rhythms are engaged throughout the human cortex in cognitive functions. How the rhythms of various low and high frequencies are spatiotemporally coordinated across the human brain during memory processing is inconclusive. They can either be coordinated together across a wide range of the frequency spectrum or induced in specific bands. We used a large dataset of human intracranial electroencephalography...
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Low-Profile Interdigitated UHF RFID Tag Antenna for Metallic Objects
PublikacjaThis article presents a novel miniature interdigitated ultra-high frequency (UHF) radio frequency identification (RFID) tag antenna that can be placed on metallic objects. The tag structure comprises two horizontal strip lines, each loaded with seven identical open stubs, and an integrated circuit (IC) chip connected directly to the feed lines in the middle of the structure. The perfect match to the IC chip’s impedance is realized...
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Fast geometry scaling of miniaturized microwave couplers with power split correction
PublikacjaRedesigning a microwave circuit for various operating conditions is a practically important yet challenging problem. The purpose of this article is development and presentation of a technique for fast geometry scaling of miniaturized microwave couplers with respect to operating frequency. Our approach exploits an inverse surrogate model constructed using several reference designs that are optimized for a set of operating frequencies...
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Expedited simulation-driven design optimization of UWB antennas by means of response features
PublikacjaIn this work, a method for fast design optimization of broadband antennas is considered. The approach is based on a feature-based optimization (FBO) concept where reflection characteristics of the structure at hand are formulated in terms of suitably defined feature points. Redefinition of the design problem allows for reducing the design optimization cost, because the dependence of feature point coordinates on antenna dimensions...
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Behavior of residual current devices at frequencies up to 50 kHz
PublikacjaThe use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied...
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Miniaturized uniplanar triple-band slot dipole antenna with folded radiator
PublikacjaA miniaturized uniplanar slot dipole for triple-frequency operation is presented. The antenna consists of a folded slot radiator with an increased number of degrees of freedom that allow for efficient size reduction. Rigorous electromagnetic (EM)-driven design optimization is applied in order to achieve the smallest possible size while maintaining acceptable levels of antenna reflection at the required operating frequencies. The...
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An Analysis of Elliptical-Rectangular Multipatch Structure on Dielectric-Coated Confocal and Nonconfocal Elliptic Cylinders
PublikacjaA rigorous analysis of the resonance frequency problem of an elliptical-rectangular microstrip structure mounted on dielectric-coated elliptic conducting cylinder, with electrically small radius, is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. The analysis is carried out considering the expansion of the field as a series of Mathieu functions. The complex resonance frequencies of...
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Nonlinear Impedance as Possible Result of Ion-Polaron Interaction in Cu2O-Al2O3-SiO2 Glass
PublikacjaNonlinear a.c. impedance measurements were performed in Cu2O-Al2O3-SiO2 glass in wide frequency range. The obtained results shows that a large nonlinearity in the impedance signal is observed at moderate electric fields of an order 1V/mm. The contents of the third harmonics reaches about 10% and strongly depends on temperature and frequency. The investigated glass exhibits mixed electronic-ionic conductivity. Electronic conduction...
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Simulation of Signal Propagation Along Fractional-Order Transmission Lines
PublikacjaIn this paper, the simulation method of signal propagation along fractional-order (FO) transmission lines is presented. Initially, fractional calculus and the model of FO transmission line are introduced. Then, the algorithm allowing for simulation of the nonmonochromatic wave propagation along FO transmission lines is presented. It employs computations in the frequency domain, i.e., an analytical excitation is transformed to the...
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Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
PublikacjaThe Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized...
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Recent trends in determination of neurotoxins in aquatic environmental samples
PublikacjaAnatoxins, saxitoxins, ciguatoxins, beta-N-methylamino-l-alanine and its isomers are groups of neurotoxins which have a highly specific effect on the nervous system of animals, including humans, by interfering with the transmission of nerve impulses. In order to assess the human exposure to these neurotoxins, selective, interlaboratory-validated analytical methods are being developed to facilitate obtaining reliable results on...
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Green sample preparation techniques for chromatographic determination of small organic compounds
PublikacjaAccurate monitoring of the state of the environment requires the introduction of additional isolation and/or preconcentration step prior to the chromatographic determination. In this work the information about novel methodological and instrumental solutions in relation to different variants of microextraction techniques are presented. Attention is focused on analytical procedure and suitable analytical tools for extraction of the...
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Experimental research on evolutionary path planning algorithm with fitness function scaling for collision scenarios
PublikacjaThis article presents typical ship collision scenarios, simulated using the evolutionary path planning system and analyses the impact of the fitness function scaling on the quality of the solution. The function scaling decreases the selective pressure, which facilitates leaving the local optimum in the calculation process and further exploration of the solution space. The performed investigations have proved that the use of scaling...
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Application of 3D printing metal powder technology in the manufacture of components with complex geometries
PublikacjaThe possibilities of using 3D printing powder technologies for making objects with complex geometries were presented. For this purpose, selected examples of elements with different geometries were used, which were built using metal powder methods – DMLS (direct metal laser sintering) / SLM (selective laser melting). Simultaneously, the indicated elements concern those areas of industry where 3D printing technology has been widely...
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Optimization of Single-Sided Lapping Kinematics Based on Statistical Analysis of Abrasive Particles Trajectories
PublikacjaThe chapter presents the influence of selected kinematic parameters on the geometrical results of the single-sided lapping process. The optimization of these parameters is aimed at improving the quality and flatness of the machined surfaces. The uniformity of tool wear was assumed as main optimization criterion. Lapping plate wear model was created and in detail was analyzed. A Matlab program was designed to simulate the abrasive...
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Periodic expansion in determining minimal sets of Lefschetz periods for Morse–Smale diffeomorphisms
PublikacjaWe apply the representation of Lefschetz numbers of iterates in the form of periodic expansion to determine the minimal sets of Lefschetz periods of Morse–Smale diffeomorphisms. Applying this approach we present an algorithmic method of finding the family of minimal sets of Lefschetz periods for Ng, a non-orientable compact surfaces without boundary of genus g. We also partially confirm the conjecture of Llibre and Sirvent (J Diff...
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Scientific research in the Department of Machine Design and Automotive Engineering
PublikacjaShort descriptions of various research subjects taken up at the Department of Machine Design and Automotive Engineering are included in the paper. The subjects cover a wide range of bearing systems and tribology research and the research on tires and road surfaces. A third field of activity is biomedical engineering – with the attempts to improve methods of modelling biological materials in FEM calculations. The Department has...
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Analysis of noise properties of the optocoupler device
PublikacjaIn the paper the localization of a source of Random Telegraph Signal noise (RTS noise) in optocoupler devices type CNY 17 were defined. The equivalent noise circuit in low frequency noise for these type optocouplers was proposed.
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Role of the Solvation Water in Remote Interactions of Hyperactive Antifreeze Proteins with the Surface of Ice
PublikacjaMost protein molecules do not adsorb onto ice, one of the exceptions being so-called antifreeze proteins. In this paper, we describe that there is a force pushing an antifreeze protein molecule away from the ice surface when it is not oriented with its ice-binding plane toward the ice and that this pushing force may be also present even when the protein is oriented with its ice-binding plane toward the ice. This force is absent...
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Corrosion Resistance and Surface Bioactivity of Ti6Al4V Alloy after Finish Turning under Ecological Cutting Conditions
PublikacjaThe influence of cooling conditions and surface topography after finish turning of Ti6Al4V titanium alloy on corrosion resistance and surface bioactivity was analyzed. The samples were machined under dry and minimum quantity lubrication (MQL) conditions to obtain different surface roughness. The surface topographies of the processed samples were assessed and measured using an optical profilometer. The produced samples were subjected...
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Worm Gear Drives with Improved Kinematic Accuracy
PublikacjaThis paper presents the fundamentals of the design and applications of new worm gear drive solutions, which enable the minimisation of backlash and are characterised by higher kinematic accuracy. Different types of worm surfaces are briefly outlined. Technological problems concerning the principles of achieving a high degree of precision in machining are also described. Special attention is paid to the shaping of conical helical...
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Surface modification of PMMA polymer and its composites with PC61BM fullerene derivative using an atmospheric pressure microwave argon plasma sheet
PublikacjaThis paper presents the results of experimental investigations of the plasma surface modification of a poly(methyl methacrylate) (PMMA) polymer and PMMA composites with a [6,6]-phenyl-C61-butyric acid methyl ester fullerene derivative (PC61BM). An atmospheric pressure microwave (2.45 GHz) argon plasma sheet was used. The experimental parameters were: an argon (Ar) flow rate (up to 20 NL/min), microwave power (up to 530 W), number...
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Selektywne chłodzenie mózgu noworodka po niedotlenieniu okołoporodowym. Cześć 2. Koncepcja hybrydowego systemu selektywnego chłodzenia mózgu noworodka
PublikacjaMózg ludzki jest organem delikatnym, dlatego tak ważne jest zadbanie o to, aby już w momencie przyjścia na świat noworodek miał zapewnioną, w razie konieczności możliwość minimalizacji uszkodzeń neurologicznych, spowodowanych niedotlenieniem okołoporodowym. Niedotlenienie to w dramatyczny sposób zaburza homeostazę mózgu, który jako organ najbardziej energochłonny potrzebuje najwięcej tlenu. Zapoczątkowane brakiem tlenu procesy...
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Dynamic mass measurement in checkweighers using a discrete time-variant low-pass filter
PublikacjaConveyor belt type checkweighers are complex mechanical systems consisting of a weighing sensor (strain gauge load cell, electrodynamically compensated load cell), packages (of different shapes, made of different materials) and a transport system (motors, gears, rollers). Disturbances generated by the vibrating parts of such a system are reflected in the signal power spectra in a form of strong spectral peaks, located usually in...
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FIR Filter Design Using Distributed Maximal Flatness Method
PublikacjaIn the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness”...
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Dynamika bezzałogowego aparatu latającego w układzie czterowirnikowego pionowzlotu
PublikacjaDziałanie maszyn, w tym również pojazdów latających, jest nieodłącznie związane z przekazywaniem oddziaływań siłowych: statycznych i dynamicznych. Dynamika jest działem mechaniki zajmującym się makroskopowym ruchem ciał przy uwzględnieniu przyczyn wywołujących ten ruch. Pierwszym etapem analizy dynamiki konstrukcji są zwykle obliczenia wartości i postaci drgań własnych modelu konstrukcji. Drgania własne zwykle ulegają szybkiemu...
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Zastosowanie metody galwanostatycznej do wyznaczania błędu fazy elektrod woltamperometrycznych
PublikacjaW pracy przeanalizowano właściwości metrologiczne elektrod woltamperometrycznych w dziedzinie częstotliwości. Wykazano, że w przypadku, gdy reakcja elektrochemiczna kontrolowana jest procesem transportu jonów, elektroda woltamperometryczna zachowuje się tak jak przetwornik pomiarowy I rzędu. Jej właściwości metrologiczne opisane są przez czułość, częstotliwość graniczną, błąd amplitudy i błąd fazy. Przeprowadzona analiza pokazała,...
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LabVIEW-based intelligent system of protection against electric shock for photovoltaic installations
PublikacjaEvaluation of shock hazard in installations with photovoltaic sources of energy is more complicated than in a conventional low voltage system. In case of earth fault in photovoltaic generators, that are connected to the AC power public grid, a composite waveform of earth fault current in the installation may occur. For composite waveforms, the safety criteria should be modified. The paper considers the effect of the composite waveforms...
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A conceptual design and numerical analysis of the mixerless urea-SCR system
PublikacjaIn the present study, an innovative design of the urea-selective catalytic reduction (SCR) system without conventional mixing elements was developed. The aim was to obtain a high degree of urea decomposition, and uniform ammonia distribution at the inlet to the catalyst, while minimising the liquid film deposition and keeping the compact design. The concept of the design was based on creating high turbulences and elongating...
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Detection of some volatile degradation products released during photoexposition of ranitidine in a solid state
PublikacjaRanitidine (RAN) is on top of the list of prescribed drugs, due to its popularity as a selective H2-receptor antagonist, which efficiently decreases the amount of acid produced in the stomach. RAN is not stable both in a solid state and in a solution, which creates manufacturing problems, requires appropriate storage conditions, and results in a short drug shelf-life. The aim of this work was to study the emission of volatile...
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Targeting shelterin proteins for cancer therapy.
PublikacjaAs a global health challenge, cancer prompts continuous exploration for innovative therapies that are also based on new targets. One promising avenue is targeting the shelterin protein complex, a safeguard for telomeres crucial in preventing DNA damage. The role of shelterin in modulating ataxia- telangiectasia mutated (ATM) and ataxia-telangiectasia and Rad3-related (ATR) kinases, key players in the DNA damage response (DDR),...
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On the necessity of experimental verification of numerical results in biomedical applications
PublikacjaPorous structures made of metal or biopolymers with a structure similar in shape and mechanical properties to human bone can be easily produced by stereolitography techniques, e.g. selective laser melting (SLM). Numerical techniques, like finite element method (FEM) have great potential in testing new, even the most sophisticated designs, according to their mechanical properties, i.e. strength or stiffness. However, due to different...
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Synthesis of disubstituted 1,3,4,9-tetrahydropyrano-[3,4-b]indole-1-acetic acids derivatives
Publikacja1,3,4,9-tetrahydropyrano[3,4-b ]indole-1-acetic acid derivatives are of interest for pharmaceutical research as a core structure for synthesis of biological active substance - Etodolac (selective Cyclooxygenase-2 inhibitor, which belongs to the Non-steroidal Anti-inflammatory Drug, NSAID, that shows a clin-ically effective analgesic and anti-inflammatory activity). Here the way of synthesis of two 1,3,4,9-tetrahydropyrano[3,4-b...
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1,3,4-Thiadiazole-based diamides: Synthesis and complexation properties
PublikacjaAromatic diamides, derivative of 2,6-pyridinedicarboxylic acid and isophthalic acid, bearing 1,3,4-thiadiazole residue were prepared with satisfactory yields in conventional procedures and microwave stimulated reactions. X-ray structure of N,N-bis (1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide (2) DMSO solvate (2DMSO) was described. Selective zinc(II), lanthanum(III), terbium(III) and L-tyrosine recognition was found for N,N-bis(1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide...
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Pervaporation Zeolite-Based Composite Membranes for Solvent Separations
PublikacjaThanks to their well-defined molecular sieving and stability, zeolites have been proposed in selective membrane separations, such as gas separation and pervaporation. For instance, the incorporation of zeolites into polymer phases to generate composite (or mixed matrix) membranes revealed important advances in pervaporation. Therefore, the goal of this review is to compile and elucidate the latest advances (over the last 2-3 years)...
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Reviewing the recent developments of using graphene-based nanosized materials in membrane separations
PublikacjaAccording to the potentialities of graphene-based materials and their unique physicochemical properties. Such 2D nanomaterials are likely to be the most implemented within the improvement of the selective separations of polymer membranes, together with enhanced physicochemical properties (such as hydrophilicity/hydrophobicity, transport of molecules, mechanical and thermal features, among others). Hence, this review compiles and...
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Resonance in Rectangular Microstrip Structure Loaded with a Pseudochiral Medium Layer
PublikacjaA rectangular microstrip structure with multilayer substrate containing dielectric and pseudochiral medium layers is studied in this paper. The effect of Omega medium layer location in the substrate and its thickness on the complex resonant frequency of the rectangular microstrip structure is investigated.
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Optimal Components Design for Modified Z-Source Based IPT Approach
PublikacjaThis paper describes components estimation process for IPT approach based on Z-source network. Proposed model covers main parameters of the system and gives efficient way to evaluate optimal parameters for fixed switching frequency and distance.