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Search results for: MICROWAVE PLANAR SENSOR
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Application of fiber optic sensors using Machine Learning algorithms for temperature measurement of lithium-ion batteries
PublicationOptical fiber sensorsusing low-coherence interferometry require processing ofthe output spectrum or interferogramto quickly and accurately determine the instantaneous value of the measured quantity, such as temperature.Methods based on machine learning are a good candidate for this application. The application of four such methods in an optical fiber temperature sensoris demonstrated.Using aZnO-coated...
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Fluctuation-Enhanced Sensing with Organically Functionalized Gold Nanoparticle Gas Sensors Targeting Biomedical Applications
PublicationDetection of volatile organic compounds is a useful approach to non-invasive diagnosis of diseases through breath analysis. Our experimental study presents a newly developed prototype gas sensor, based on organically-functionalized gold nanoparticles, and results on formaldehyde detection using fluctuation-enhanced gas sensing. Formaldehyde was easily detected via intense fluctuations of the gas sensor’s resistance, while the cross-influence...
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Nitrogen dioxide sensing properties of PEDOT polymer films
PublicationThis work presents a simple and fully electrochemical route for the polymerization of poly(3,4-ethylenedioxytiophene) (PEDOT) films for fabricating a NO2 gas sensor prepared by electropolymerization of 3,4-Ethylenedioxythiophene (EDOT) monomer in lithium perchlorate/acetonitrile solution. The main aim of this study is to determine the sensing properties of conductive polymer at elevated temperatures. The effects of the humidity,...
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Scalable Measurement System for Multiple Impedance Gas Sensors
PublicationAuthor proposes scalable architecture of the measurement system for gas sensor with impedance dependance of the gas concentration. The main part of the system is a single-board impedance analyser. The number of analysers working in parallel can be configured according to specific application. The system is controlled by a single computer which organises the measurement cycle and store the acquired measurement data. The system is...
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The silver layers in fiber-optic sensors
PublicationIn this paper a method of application of the silver layers on the surface of an optical fiber was proposed. The optical properties and surface quality of the silver layer was examined by optical microscopy. The reflection and transmission of the sample were investigated. To evaluate the silver mirror it was placed in a fiber optic Fabry-Perot interferometer and the quality of the spectra was analyzed. The commercial mirror was...
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Nitrogen-doped diamond thin films: potential application in Fabry-Pérot interferometer
PublicationIn this paper we present results of preliminary research of using nitrogen-doped diamond (NDD) films as reflective layer in Fabry-Pérot interferometer. NDD films were deposited on Si substrates by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) with the use of CH4, H2 and N2 gas mixtures. During deposition process methane flow rate varied while nitrogen flow was constant. We performed series of measurements which showed...
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Optoelectronic system for investigation of cvd diamond/DLC layers growth
PublicationDevelopment of the optoelectronic system for non-invasive monitoring of diamond/DLC (Diamond-Like-Carbon) thin films growth during μPA ECR CVD (Microwave Plasma Assisted Electron Cyclotron Resonance Chemical Vapour Deposition) process is described. The system uses multi-point Optical Emission Spectroscopy (OES) and long-working-distance Raman spectroscopy. Dissociation of H2 molecules, excitation and ionization of hydrogen atoms...
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Creating Dynamic Maps of Noise Threat Using PL-Grid Infrastructure
PublicationThe paper presents functionality and operation results of a system for creating dynamic maps of acoustic noise employing the PL-Grid infrastructure extended with a distributed sensor network. The work presented provides a demonstration of the services being prepared within the PLGrid Plus project for measuring, modeling and rendering data related to noise level distribution in city agglomerations. Specific computational environments,...
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Zastosowanie elektronicznych zmysłów w analizie żywności. Zastosowanie elektronicznego języka w analizie żywności.
PublicationW dzisiejszych czasach konsumenci zwracają dużą uwagę na takie cechy żywności jak: zapach, smak i wygląd. Ze względu na to naukowcy od wielu lat podejmują próby naśladowania ludzkich narządów zmysłów za pomocą urządzeń określanych jako elektroniczne zmysły. Zaliczamy do nich elektroniczny nos i język oraz komputerowy system rozróżnienia barw i kształtów. Elektroniczny język znany również jako sztuczny język lub czujnik smaku,...
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Low-Cost Multi-Objective Optimization Yagi-Uda Antenna in Multi-Dimensional Parameter Space
PublicationA surrogate-based technique for fast multi-objective optimization of a multi-parameter planar Yagi-Uda antenna structure is presented. The proposed method utilizes response surface approximation (RSA) models constructed using training samples obtained from evaluation of the low-fidelity antenna model. Utilization of the RSA models allowsfor fast determination of the best possible trade-offs between conflicting objectives in multi-objective...
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Propagation of initially sawtooth periodic and impulsive signals in a quasi-isentropic magnetic gas
PublicationThe characteristics of propagation of sawtooth periodic and impulsive signals at a transducer are analytically studied in this work. A plasma under consideration is motionless and uniform at equilibrium, and its perturbations are described by a system of ideal magnetohydrodynamic equations. Some generic heating/cooling function, which in turn depends on equilibrium thermodynamic parameters, may destroy adiabaticity of a flow and...
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Photovoltaic effect in the single-junction DBP/PTCBI organic system under low intensity of monochromatic light
PublicationPhotoelectric properties of the planar ITO/MoO3/DBP/PTCBI/BCP/Ag system were characterized on the basis of short-circuit current, open-circuit voltage and absorption spectra, and current-voltage measurements in the dark and under monochromatic illumination of low intensity. Photovoltaic performance of the system was compared with the performance of ideal semiconductor and excitonic cells of chosen bandgaps. Such analysis shows,...
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Reactions of the Lithiated DiphosphinetBu2P-P(SiMe3)Li with [(η6-C6H6)RuCl2]2in the Presence of Tertiary Phosphines
PublicationtBu2P–P(SiMe3)Li reacted with [(η6-C6H6)RuCl2]2at–40 °C in the presence of PR3(PR3=PEt3,PEt2Ph, PEtPh2) by the nucleophilic addition of the tBu2P–P(SiMe3) moiety to the benzene ring to yield solely the complexes [(R3P)2Ru(Cl)-{η5-C6H6(Me3SiP–PtBu2)}] (1). These products decomposed slowly at ambient temperature to yield benzene, Ru clusters, and small amounts of the dinuclear ruthenium complexes [{(R3P)2Ru}2(μ,η2:2-P2)2Ru(PR3)2](Ru–Ru)(6)....
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Hysteresis curves for some periodic and aperiodic perturbations in magnetosonic flow
PublicationA thermodynamic relation between perturbations of pressure and mass density in the magnetohydrodynamic flow is theoretically studied. Planar magnetohydrodynamic perturbations with the wave vector, which forms a constant angle with the equilibrium magnetic field, are under study. The theory considers thermal conduction of a plasma and the deviation from adiabaticity of a flow due to some kind of heating–cooling function. It also...
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A design framework for rigorous constrained EM-driven optimization of miniaturized antennas with circular polarization
PublicationCompact radiators with circular polarization are important components of modern mobile communication systems. Their design is a challenging process which requires maintaining simultaneous control over several performance figures but also the structure size. In this work, a novel design framework for multi-stage constrained miniaturization of antennas with circular polarization is presented. The method involves sequential optimization...
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A compact microstrip rat-race coupler constituted by nonuniform transmission lines
PublicationIn this work, a step-by-step development of a compact microstrip rat-race coupler (RRC) has been presented and discussed. A high degree of miniaturization has been obtained by substituting six quarter-wavelength uniform atomic building blocks of a RRC by their nonuniform counterparts. The miniaturization procedure has been realized in three progressive steps: (i) the first layout solution of a miniaturized RRC has been acquired...
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Miniaturized uniplanar triple-band slot dipole antenna with folded radiator
PublicationA 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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A structure and design optimization of novel compact microscrip dual-band rat-race coupler with enhanced bandwidth
PublicationIn the letter, a topology of a novel compact wideband dual-band rat-race coupler has been presented along with its computationally efficient design optimization procedure. Reduction of the circuit size has been achieved by meandering transmission lines of the conventional circuit. At the same time, the number of independent geometry parameters has been increased so as to secure sufficient flexibility of the circuit, necessary in...
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Novel doubly perforated broadband microstrip branch-line couplers
PublicationTwo broadband compact doubly perforated hybrid couplers have been designed, manufactured, and measured. To improve frequency characteristics and to reduce circuit dimensions, two kinds of perforations have been introduced: the defected ground structures in the ground plane metallization and photonic bandgap cells in the strip metallization. Measurement results show essential miniaturization (~39% and ~36%) and enhancement of the...
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Novel microstrip low-pass filters with fractal defected ground structures
PublicationIn this study, three microstrip low-pass filters (LPFs) containing fractal-shaped defected ground structures have been designed and manufactured. To improve the performance of microstrip LPF, cascades of inductively coupled fractal resonators have been applied. Simultaneously, to achieve relatively constant microstrip impedance resulting in essentially low reflection losses, a modification of the strip geometry has been introduced....
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Improved selectivity compact band-stop filter with gosper fractal-shaped defected ground structures
PublicationA novel band-stop filter using Gosper fractal-shaped defected ground structures has been designed and manufactured. The improvement in the filter selectivity has been achieved by introducing a multiresonance fractal-shaped defect leading to a higher filter order, simultaneously maintaining its compact size. The experimental results prove the validity of proposed solution and its utility in novel miniaturized and severe requirement...
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A compact seven-section rat-race hybrid coupler incorporating pbg cells
PublicationA conventional rat-race coupler has been doubly miniaturized: (i) characteristic impedances and electrical lengths of microstrip sections have been adequately modified as the first step of size reduction and (ii) T-shaped PBG cells have been implemented to diminish strip section length as the second step of circuit rat-race couplerminiaturization. The experimental results show good agreement with theoretical characteristics. Furthermore,...
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Slow-wave fractal-shaped compact microstrip resonant cell
PublicationA novel fractal-shaped compact microstrip resonant cell (CMRC) featuring a strong slow-wave effect has been presented. Its vital usefulness in the process of microstrip line miniaturisation has been proved and experimentally validated on the basis of a compact 3-dB branch-line coupler illustrating the possibilities of the approach. A prototype example structure has been designed to mirror the characteristics of a conventional device,...
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Design of a broadband microstrip crossover for ultra-wideband applications
PublicationW pracy przedstawiono badania skrzyżowań linii mikropaskowych do zastosowań w systemach UWB. W procedurze projektowej wykorzystany został model zastępczy skrzyżowania. W celu poprawy parametrów skrzyżowań zaprojektowano dwie konfiguracje obwodów kompensujących. Wyniki numeryczne zweryfikowane zostały eksperymentalnie. Uzyskano dobrą zgodność pomiędzy rezultatami symulacji oraz pomiarów.
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Application of the discrete Green's function-based antenna simulations for excitation of the total-field/scattered-field interface in the FDTD method
PublicationIn this article, the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method is proposed for simulation of wire antennas irradiating inhomogeneous dielectric scatterers. Surface equivalence theorem in the discrete domain is used to separate the problem into an inhomogeneous domain and a wire antenna that are simulated with the use of FDTD and DGF-FDTD, respectively. Then, the excitation of the...
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Investigations of the circulation effects in the structure using ferrite coupled slot-line section
PublicationW artykule przedstawiono badania cyrkulatora zrealizowanego w oparciu o magnesowaną wzdłużnie sekcję ferrytowych szczelinowych linii sprzężonych. Zaproponowane rozwiązanie pozwala na minimalizację rozmiarów układu cyrkulatora oraz na uzyskanie parametrów porównywalnych z dotychczas publikowanymi. W treści artykułu opisano kolejne etapy projektu. Wyniki numeryczne zweryfikowano eksperymentalnie. Pomierzony układ charakteryzował...
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A novel compact broadband 5-35GHz
PublicationW artykule przedstawiono zasadę pracy oraz procedurę projektowania zintegrowanego planarnego baluna (symetryzatora). Układ zaprojektowano wykorzystując połączenie linii paskowych i szczelinowych oraz struktury rezonatorów w formie wielogałęziowych sęków szczelinowych. Wykonany wielowarstwowy symetryzator pracuje poprawnie w zakresie 5-35GHz.
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Microstrip line with short-circuited edge as a high-pass filter operating up to millimeter-wave frequencies
PublicationPrzedstawiono prosty planarny filtr górnoprzepustowy wykorzystujący linię mikropaskową ze zwartym brzegiem. Układy zaprojektowano w taki sposób, aby pasmo przepustowe rozpoczynało się w zakresie K lub Ka. Wykonano dwa prototypy: na podłożu w postaci warstwy dielektrycznej wykonanej z ceramiki alundowej oraz na podłożu organicznym o niskiej przenikalności elektrycznej. Wykazano dużą zgodność teoretycznych i pomierzonych charakterystyk...
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Doubly miniaturized rat-race hybrid coupler
PublicationTwo complementary miniaturization techniques have beenapplied to reduce the size of a rat-race hybrid coupler: (i) conventional microstrip sections have been replaced with their diminished lowimpedance counterparts as the first step of size reduction and (ii) novel fractal-shaped compact microstrip resonant cells dedicated to efficiently shorten low-impedance transmission line segments have been implemented as the second step of...
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Simulation and experiment of radiating slot in a ground-plane of microstrip junction
PublicationW pracy przedstawiono badania numeryczne oraz eksperymentalne szczeliny promieniującej umieszczonej w płaszczyźnie masy złącza mikropaskowego. Złącze mikropaskowe składa się z linii mikropaskowej oraz rozwartego na końcu sęka. Szczelina umieszczona jest równolegle do linii mikropaskowej.
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Design considerations for compact microstrip resonant cells dedicated to efficient branch-line miniaturization
PublicationA conventional compact microstrip resonant cell (CMRC)has been thoroughly investigated to enhance its slow-wave properties and subsequently ensure an efficient miniaturization of a microstrip circuit. The geometry of a classic CMRC has been improved in terms of slowwave effect in two progressive steps: (i) a single-element topology has been replaced with a double-element one and (ii) a high-impedance section has been refined by...
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Novel topology of compact coplanar waveguide resonant cell low-pass filter
PublicationIn this study, a novel pseudoelliptic function low-pass filter (LPF) constituted by a compact coplanar waveguide resonant cell has been designed and manufactured. The lumped-element seven-pole prototype has been adequately realized by using complementary perturbations located both in signal line and ground plane metallization. The fabricated uniplanar LPF offers a compact size of 5.6 x 9.8 mm2, return loss better than 26 dB over...
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IFF/SSR rectangular patch antenna with reduced transversal size
PublicationW artykule przedstawiono antenę mikropaskową dla systemów IFF/SSR, zasilaną poprzez szczelinę typu H. Zastosowanie tego typu szczeliny pozwoliło na 36-procentową redukcję wymiaru poprzcznego anteny,co jest szczególnie istotne ze względu na potencjalne zastosowanie anteny w szykach.Pomierzone parametry eektryczne anteny to: VSWR < 1.5; stosunek polaryzacji ortogonalnej do właściwej < 30 dB w obu płaszczyznach;zysk > 7 dBi.
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Effect of ground plane size on radiation pattern in IFF/SSR microstrip antenna on thick substrate fed by H type slot
PublicationW pracy pokazano numeryczne i eksperymentalne wyniki badania wpływu rozmiarówmasy na charakterystyki promieniowania anteny dla zastosowań IFF/SSR, zrealizowanej na grubym podłożu i zasilanej przez szczelinę typu H. Pokazane wyniki dla anteny oryginalnej porównano z wynikami uzyskanymi po zmniejszeniu wymiarów masy (w każdym z kierunków). Pokazano jak dalece można zminimalizować wymiary anteny, przy założonym poziomie listków bocznych.
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Application of hybrid finite-difference mode-matching method to analysis of structures loaded with axially-symmetrical posts
PublicationW artykule przedstawiono nową metodę hybrydową do analizy układów falowodowych zawierających dowolne konfiguracje obiektów osiowo-symetrycznych. Metoda oparta jest na połączeniu metody różnic skończonych, metody dopasowania rodzajów oraz iteracyjnej procedury rozpraszania. W pracy przedstawiono badania zbieżności metody. Uzyskane wyniki numeryczne porównano z wynikami odniesienia. Duża zgodność wyników potwierdziła poprawność opracowanego...
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Miniaturized dual‐band branch‐line coupler with enhanced bandwidth
PublicationIn this letter, a miniaturized hybrid dual-band branch-line coupler (BLC) with enhanced fractional bandwidths is proposed. Compact size and bandwidth enhancement are obtained using meandered transmission line sections with broken symmetry between cross-coupling branches. The circuit is designed at a low numerical cost using surrogate-assisted techniques. The optimized design features small size of only 0.25λg×0.19λg(28% miniaturization...
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Novel structure and design of enhanced-bandwidth hybrid quadrature patch coupler
PublicationA novel structure and design optimization procedure of an enhanced-bandwidth hybrid quadrature patch coupler is proposed. Improved performance of the circuit has been obtained by parameterizing the coupler sections using splines, which introduces additional degrees of freedom. Due to computational complexity of the parameter adjustment problem, a sequential design procedure is applied. In each iteration, a selected number of spline...
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Electromagnetic wave scattering by a set of axially symmetric omega-medium cylinder
PublicationZaprezentowano analizę rozproszenia fali elektromagnetycznej od układu obiektów cylindrycznych zbudowanych z materiałów pseudochiralnych, umieszczonych w złączach falowodowych lub wolnej przestrzeni. Analiza bazuje na iteracyjnej procedurze rozproszenia i metodzie dopasowania rodzajów.
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Radiation phenomena from pseudochiral cylinders at plane wave incidence
PublicationPrzedstawiono wpływ materiałów pseudochiralnych na charakterystyki rozproszenia fali elektromagnetycznej od obiektów cylindrycznych. W celu zbadania zjawisk rozproszenia zastosowano kombinacje iteracyjnej procedury rozproszenia i metodę dopasowania rodzajów. Wpływ zastosowania materiałów pseudochiralych w konfiguracjach obiektów cylindrycznych zaprezentowano na charakterystykach pola rozproszonego w strefie dalekiej oraz na charakterystykach...
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Influence of dopants on structure of polycrystalline bismuth niobate
PublicationBismuth niobate (BiNbO4) has attracted attention as a low-fired ceramics with promising microwave application potential. BiNbO4 ceramics was fabricated by mixed oxide method and sintered at temperature T<1000˚C. As the sintering aids a small amount of CuO oxide was used. The crystalline structure of the ceramic samples was examined by X-ray diffraction method at room temperature. The Rietveld refinement method was used for analysis...
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Assessing the industrialization progress of hydrodynamic cavitation process intensification technology: a review
PublicationHydrodynamic cavitation (HC) is widely acknowledged as a promising green approach for enhancing various production and waste management processes, such as water treatment, sludge pretreatment, lignocellulosic biomass (LCB) pretreatment, emulsification, and food processing. Despite demonstrating superior industrialization potential compared with other emerging technologies such as ultrasound and microwave, the widespread commercial...
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Salicylaldimine-based receptor as a material for iron(III) selective optical sensing
Publicationα,α-Bis(salicylimino)-m-xylene (L) was prepared using both conventional and microwave-assisted procedure. The compound exhibits ability to colorimetric recognition of iron(III) ions in aqueous environment, what is shown by significant color change from yellow to purple. In DMSO : water (9:1 v/v) solvent system receptor creates with iron(III) cations complexes of 2:1 stoichiometry (L:Fe3+) with stability constant (log K) 7.54±0.21....
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Local mesh morphing technique for parametrized macromodels in the finite element method
PublicationThis paper presents a novel approach for enhancing the efficiency of the design process of microwave devices by means of the finite element method. It combines mesh morphing with local model order reduction (MOR) and yields parametrized macromodels that can be used to significantly reduce the number of variables in the FEM system of equations and acceleration of computer simulation. A projection basis for local reduction is generated...
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The influence of small amount of substances present in tissue on the optical spectrum of immunosuppressive drug
PublicationIn this paper, we describe how commonly present in tissue substances - sodium chloride and glucose - affect the optical spectrum of an immunosuppressive drug (Cyclaid® by Apotex). Prepared samples were investigated using the spectrophotometer in the spectrum range from 250 nm to 1100 nm. The maximum wavelength shift calculated on the basis of measurement results is not bigger than the measurement wavelength step. So, it can be...
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Monitoring of single-side lap grinding with electroplated tools
PublicationThe results presented in the paper show that utilising microphones as audible sound sensors is a suitable approach for monitoring a single-side lap grinding process due to the low levels of noise generated by the drives of a machine tool. The results confirm that sound signal analysis is a feasible and relatively simple method to monitor a lap grinding process with the use of an audible sound sensor. Proposed method can be used...
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Tuning transfer function of fiber-optic Fabry-Pérot interferometer via introduction of birefringence in the cavity
PublicationThe study investigates the impact of birefringence exhibited by the cavity material of a fiber-optic Fabry-Pérot interferometer on its transfer function. The theoretical approach to analyze the effect of birefringence in the cavity of a plane Fabry-Pérot interferometer is described. The case of high- and low-finesse interferometer is investigated. It is shown that introduction of a birefringent medium of optimized parameters can...
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Wybrane aspekty oceny jakości produktów żywnościowych
PublicationPrzedstawiono wybrane aspekty oceny jakości produk tów żywnościo- wych: pojęcie jakości, wybrane metody oceny jakości ze szczególnym uwzględ- nieniem sztucznych potencjometrycznych sensorów sma ku składających się z szeregu elektrod typu ISE (Ion Selective Electrodes ) oraz ASSE (All Solid State Electrodes). Omówiono działanie sztucznych sensorów smaku. Przedstawiono 10 potencjometryczny sensor wprowadzony do obrotu hand lowego....
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Badania nad potencjometrycznymi sensorami smaku
PublicationPrzedstwiono badania nad 5-kanałowym sensorem smaku kwasnego, zbudowanym z elektrod z membranami polimerowo - lipidowymi zawierającymi odpowiednie lipidy. Stwierdzono, że sensor ten jest bardzo czuły na zmainy stężenia kwasu cytrynowego, natomiast wykazuje nieco gorszą czułosc na obecnosć kwasu octowego. Stwirdzono dobrą trwałosć membran oraz powtarzalnośc otrzymanych wyników. Wydaje się, że badane układy mogą byc wykorzystane...
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Magnetic field microsensor based on GaAs MESFET
PublicationA novel concept of the drain separation design in a horizontally-split-drain GaAs MAGFET sensor, based on epitaxial layer growth, was developed. Proper choice of GaAs/AlAs/GaAs epitaxial layer sequence provided good electrical isolation between the drain regions. The measured leakage current between the drain regions was in the range of nA for up to 2V drain voltage bias difference. Performed analytical and numerical calculations...
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Review of Recent Advancement on Nature/Bio-inspired Antenna Designs
PublicationThis article presents an extensive examination of antennas rooted in nature and biology, showcasing their remarkable performance across a wide spectrum of frequencies—from microwave to terahertz. The limitations of traditional antenna design have become increasingly evident in the face of burgeoning demands for novel communication technologies. Conventional analytical-equation-based approaches struggle to deliver the combined performance...