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Wyniki wyszukiwania dla: DISPERSIVE-DELAY STRUCTURE (DDS)
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RF Multi-Functional Input-Reflectionless Dispersive-Delay Structure With Sharp-Rejection Filtering Using Channelization Techniques
PublikacjaA class of RF multi-functional input-reflectionless dispersive-delay structure (DDS) with linear-type in-band groupdelay variation and sharp-rejection bandpass-filtering capability is reported. It exploits a two-branch-channelized/balanced-type circuit with similar low-order reflective DDS units inside its channels, which are connected through input/output 3-dB quadrature wideband couplers. The adopted DDS unit is based on a coupledresonator...
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Dispersive Delay Structures With Asymmetric Arbitrary Group-Delay Response Using Coupled-Resonator Networks With Frequency-Variant Couplings
PublikacjaThis article reports the design of coupled-resonatorbased microwave dispersive delay structures (DDSs) with arbitrary asymmetric-type group delay response. The design process exploits a coupling matrix representation of the DDS circuit as a network of resonators with frequency-variant couplings (FVCs). The group delay response is shaped using complex transmission zeros (TZs) created by dispersive cross-couplings. We also present an...
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RF Input-Quasi-Reflectionless Dispersive-Delay Structures Based on Complementary-Diplexer Circuits
PublikacjaA class of RF dispersive-delay structures (DDSs) with input-quasi-reflectionless behavior is reported. It is based on the exploitation of complementary-diplexer circuit networks, in which the out-of-band RF-input-power echoes reflected by the main bandpass-filter-(BPF)-type channel are dissipated by the resistively-terminated auxiliary bandstop-filter-(BSF)-type channel. Specifically, it is shown that the influence of the absorptive...
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A Self-Equalized Waveguide Filter With Frequency-Dependent (Resonant) Couplings
PublikacjaThis letter presents a design of a fifth-order linear phase filter with frequency-dependent couplings. The filter is composed of a triplet that is directly coupled to two resonators at the input and output. To provide group delay flattening a cross-coupling in the trisection has a strongly dispersive character with a negative slope parameter. To achieve this, an E-plane stub with a septum was used. To further improve the filter...
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Dynamic Route Discovery Using Modified Grasshopper Optimization Algorithm in Wireless Ad-Hoc Visible Light Communication Network
PublikacjaIn recent times, visible light communication is an emerging technology that supports high speed data communication for wireless communication systems. However, the performance of the visible light communication system is impaired by inter symbol interference, the time dispersive nature of the channel, and nonlinear features of the light emitting diode that significantly reduces the bit error rate performance. To address these problems,...
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efficient fractional delay hilbert transform filter in the farrow structure
PublikacjaIn this paper the design and application of a Fractional Delay Hilbert Transform Filter (FDHTF) into an adaptive sub-sample delay estimation between two separated sinusoidal signals is considered. The FDHTF incorporates the functions of Hilbertian and variable fractional delay filtering of the incoming signal simultaneously, in one stage. In traditional approach each of these operations was performed separately. Obtained value...
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A complex variable fractional-delay FIR filter structure
PublikacjaW artykule wprowadzamy strukturę zespolonego filtru o skończonej odpowiedzi impulsowej (ang. finite impulse response - FIR) ze zmiennym opóźnieniem ułamkowym (ang. fractional delay - FD). Strukturę tę otrzymujemy na podstawie przestrajanego filtru FD FIR o współczynnikach rzeczywistych. Stanowi ona połączenie zbioru liniowo-fazowych filtrów FIR o współczynnikach stałych rzeczywistych i dwóch łańcuchów mnożąco-akumulujących, zawierających...
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Farrow structure implementation of fractional delay filter optimal in Chebyshev sense
PublikacjaW pracy omówiono problematykę implementacji filtrów ułamkowych opóźniających o zmiennym opóźnieniu w oparciu o strukturę Farrowa. Podejście to polega na obliczeniu próbek nowej odpowiedzi impulsowej filtru dla każdego wymaganego opóźnienia w opraciu o wielomiany o współczynnikach niezależnych od opóźnienia. Prowadzi to do znacznego zmniejszenia kosztów numerycznych implementacji w zastosowaniach wymagających częstej zmiany opóźnienia...
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Versatile Structure for Variable Fractional Delay Filter Based on Extracted Window Method
PublikacjaW pracy zaproponowano nową strukturę filtru ułamkowoopóźniającego o zmiennym opóźnieniu. Struktura ta umożliwia łatwą zmianę typo oraz długości implementowanego filtru. Zaproponowana struktura jest zmodyfikowaną strukturą Farrowa, której modyfikacje bazują na koncepcji metody okien wyodrębnionych. W metodzie tej filtr prawieoptymalny projektuje się stosując pojedyncze symetryczne okno wyodrębnione z dodatkową korekcją wzmocnienia...
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Short review on the design and application of fractionl delay Hilbert transform filter using Farrow structure
PublikacjaThis paper is treated as a brief summary of our hitherto research on the design and utilization of the FDHTF, particularly in the sub-samole delay estimator.
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Adjustable fractional-delay filters utilizing the Farrow structure and multirate techniques. [Przestrajalne filtry o opóźnieniu ułamkowym wykorzystujące strukturę Farrowa i techniki wieloszybkościowe]
PublikacjaDo efektywnej realizacji ułamkowo opóźniających, przestrajalnych filtrów FIR (o skończonej odpowiedzi impulsowej) można wykorzystywać strukturę Farrowa. Jednakże, niezależnie od efektywności w porównaniu z innymi strukturami, jej złożoność implementacyjna szybko rośnie ze wzrostem szerokości pasma filtru. Celem zredukowania złożoności numerycznej, zaproponowano podejście wieloszybkościowe. W tym podejściu sygnał wejściowy jest...
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EDAX file presenting the composition of the SS316L wick structure
Dane BadawczeEnergy Dispersive X-ray Spectroscopy (EDX) measurements facilitate the determination of the chemical composition of each atom within the SS316L structure
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Two-Rate Based Low-Complexity Variable Fractional-Delay FIR Filter Structures
PublikacjaThis paper considers two-rate based structures for variable fractional-delay (VFD) finite-length impulse response (FIR) filters. They are single-rate structures but derived through a two-rate approach. The basic structure considered hitherto utilizes a regular half-band (HB) linear-phase filter and the Farrow structure with linear-phase subfilters. Especially for wide-band specifications, this structure is computationally efficient...
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Variable Ratio Sample Rate Conversion Based on Fractional Delay Filter
PublikacjaIn this paper a sample rate conversion algorithm which allows for continuously changing resampling ratio has been presented. The proposed implementation is based on a variable fractional delay filter which is implemented by means of a Farrow structure. Coefficients of this structure are computed on the basis of fractional delay filters which are designed using the offset window method. The proposed approach allows us to freely...
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Effect of Different Structure Type Traffic On Railway Line Capacity
PublikacjaThe article points to methods of analyzing railway traffic conditions based on two parameters: capacity and delay of trains. The impact of the differentiated railway type structure on the capacity of the railway line was presented. Particular attention has been paid to the assessment of commonly used simplifications in analyzes.
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Simulation Model for Application of the SDN Concept in IMS/NGN Network Transport Stratum
PublikacjaThe paper presents a simulation model allowing examination of cooperation between two currently used telecommunication networks concepts: IP Multimedia Subsystem/Next Generation Network (IMS/NGN) and Software-Defined Networking (SDN). Application of the SDN architecture elements in IMS/NGN networks will enable unified control and management of transport resources for various transport technologies and equipment manufacturers. However,...
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublikacjaIn this paper a sample rate conversion with continuouslychanging resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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Comments on “Closed Form Variable Fractional Time Delay Using FFT”
PublikacjaIn this letter drawbacks of the aforementioned paper are pointed out. The proposed approach is improved with minor modifications of the discrete frequency response. This allows for design of fractional delay filters which are close to optimal and can be efficiently implemented in the frequency domain using the sliding DFT based structure. Alternatively, the derived equivalent closed form formulae for offset windows can be used...
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Sample Rate Conversion with Fluctuating Resampling Ratio
PublikacjaIn this paper a sample rate conversion with continuously changing resampling ratio has been presented. The proposed implementation is based on variable fractional delay filter implemented using a Farrow structure. It have been demonstrated that using the proposed approach instantaneous resampling ratio can be freely changed. This allows for simulation of audio recored on magnetic tape with nonuniform velocity as well as removal...
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The structure of vanadate glasses containing BaTiO3.
Dane BadawczeThe structure of vanadate glasses doped with BaTiO3 was measured by SEM technique. Samples of the composition of x[BaO,TiO2]–(80 − x)V2O5–20Bi2O3 where x = 5, 10 and 15 in mol% were prepared by a conventional melt quenching technique. The melting was performed in alumina crucibles at the temperature of 1273 K–1373 K. The melts were poured on a preheated...
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Analytical Traffic Model for a Multidomain IMS/NGN Network Including Service and Transport Stratum
PublikacjaThis paper addresses the problem of modelling call processing performance (CPP) in a multidomain Next Generation Network (NGN) architecture including the elements of the IP Multimedia Subsystem (IMS) in service stratum and based on the Multiprotocol Label Switching (MPLS) technology in transport stratum. An analytical traffic model for such an architecture is proposed by integrating the formerly implemented submodels of service...
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Variable Fractional Delay Filter Design Using a Symmetric Window
PublikacjaIn this paper a numerically efficient method for designing a nearly optimal variable fractional delay (VFD) filter based on a simple and well-known window method is presented. In the proposed method a single window extracted from the optimal filter with fixed fractional delay (FD) is divided into even and odd part. Subsequently, the odd part is discarded and symmetric even part of the extracted window is used to design a family...
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Improvement of time difference of arrival measurements resolution by using fractional delay filters in a direct sequence-code division multiple access radionavigation system
PublikacjaThis study presents a method of improving time measurements resolution in a direct sequence-code division multiple access receiver by using a fine code tracking loop based on fractional delay filtering of a despreading sequence. It briefly describes the structure of a generic digital code tracking loop and the proposed modification which allows to measure time difference of arrival values with the subsample resolution, together...
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The structure of vanadate glass-ceramics containing BaTiO3.
Dane BadawczeThe structure of vanadate glass-ceramics doped with BaTiO3 was measured by SEM technique. Samples of the composition of x[BaO,TiO2]–(80 − x)V2O5–20Bi2O3 where x = 5, 10 and 15 in mol% were prepared by a conventional melt quenching technique. The melting was performed in alumina crucibles at the temperature of 1273 K–1373 K. The melts were poured on...
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Wave Method for Structural Health Monitoring: Testing Using Full-Scale Shake Table Experiment Data
PublikacjaAn algorithm of the wave method for structural health monitoring (SHM) is tested and calibrated using shake table experiment data of a full-scale, seven-story, reinforced-concrete building slice. The method is based on monitoring changes in the velocity of waves propagating vertically through the structure, identified by least-squares (LSQ) fit of beam models. The experiment was conducted by a team from the University of California,...
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Transparent thin films of Cu-TiO2 with visible light photocatalytic acitivity
PublikacjaThin films of Cu–TiO2 with a high level of transparency were prepared by a dip-coating procedure on the glass surface. CuCl2 was used as a copper precursor added during sol – gel synthesis of TiO2. The extension of optical absorption into the visible region of as-prepared thin films was indicated by UV/Vis spectroscopy. Only the anatase phase was detected by X-ray di ffraction analysis (XRD). The presence of copper in the structure...
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THE INFLUENCE OF WSR PARAMETER ON PET BOTTLE THICKNESS PROFILE IN SBM FROM PREFORM PROCESS
PublikacjaFrom a mechanical point of view, the thickness profile of PET bottles manufactured by ISBM process is determined by mechanical and thermal response of blown preforms. From the microscopic point of view the biggest influence on the mechanical and thermal properties of PET bottles have orientation and crystallization processes. From a technological point of view, the thickness profile of PET bottles after manufacture by SBM process...
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Structural properties of superconducting PrBa 2Cu 3O 7−δ single crystals
PublikacjaThe influence of high-temperature reduction/oxidation treatment on the structural properties of superconducting PrBa2Cu3O7−δ (PrBCO) single crystals was examined. The scanning electron microscopy (SEM) analysis has shown that even the short-lasting exposure to the oxygen-deficient atmosphere leads to creation of regular-shaped crystallites of PrBaO3 and BaCuO2 phases with the size of 0.5 ÷ 2.0 μm on the smooth and flat crystal...
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Evaluation of adhesive forces and the specific surface energy of zirconia stabilized by yttria with alumina additions ceramic by AFM method
PublikacjaThe adhesive forces and the specific surface energy of ceramic material surfaces are very important for further tribological and biomedical applications of ceramics. Partially stabilized zirconia (zirconium oxide) is popular for manufacturing various medical products. ZrO2 stabilized by Y2O3 with additions of 5 wt% alumina was produced by slip casting method with a subsequent sintering. Structure and chemical composition of ceramic...
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Aggregation of nonionic surfactants in imidazolium ionic liquids
PublikacjaMicellar aggregation of surfactants in aqueous solutions has been described in terms of the balance between dispersive interactions of the hydrocarbon part of the amphiphilic molecule, and the hydration and electrostatic repulsive effects of hydrophilic head group. Changing the interactions by replacing water with another polar solvent, such as amides or glycols, has been studied to a smaller extent (Singh, Saleem et al. 1980;...
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Ionic liquids in the microextraction techniques: the influence of ILs structure and properties
PublikacjaIonic liquids (ILs) are composed entirely of ions thus they possess unique properties, including negligible volatility, a liquid state in a broad range of temperatures and ability to change them depending on the chosen type of anion and cation, which make ILs unique and useful for many applications in sample preparation techniques. A deeper understanding of the nature of ILs and the impact of their structure on their parameters...
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Low-cost multiband four-port phased array antenna for sub-6 GHz 5G applications with enhanced gain methodology in Radio-over-fiber systems using modulation instability
PublikacjaPhased array antenna (PAA) technology is essential for applications requiring high gain and wide bandwidth, such as sensors, medical, and 5G. Achieving such a design, however, is a challenging and intricate process that calls for precise calculations and a combination of findings to alter the phase and amplitude of each unit. Furthermore, coupling effects between these PAA structure elements can only be completed with the use of...
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The Influence of Stretch Rod Speed on the Relationship between Preblown Bottle Aesthetic Quality and Final Blown Bottle Thickness Profile in Stretch Blow Molding from Preform Process
PublikacjaFrom a mechanical point of view, the aesthetic quality of preblown PET bottles and thickness profile of final blown PET bottles manufactured in ISBM process are determined by mechanical and thermal response of blown preforms. From the microscopic point of view the biggest influence on the mechanical and thermal properties of PET bottles have orientation and crystallization processes. From a technological point of view, the aesthetic...
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A novel hardware implemented programmable controller adapted to cooperate with AI tuning algorithms in real time systems
PublikacjaA novel, transistor level PID (proportional–integrating–derivative) controller is proposed that may be easily coupled with various AI algorithms responsible for adjusting its main factors. In our work we focus on a discrete-time digital approach, as it facilities realization a flexible and programmable structure that can be quickly re-configured depending on varying environment conditions. One of the novelties of the proposed solution...
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The structure of 70(2Bi2O3-V2O5) - 30SrBO7 measured with X-ray diffraction and SEM methods
Dane BadawczeThe structure changes of 70(2Bi2O3-V2O5)-30SrB4O7 glass occurred during increase in temperature was measured by XRD and SEM.
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Properties of Composite Oxide Layers on The Ti13Nb13Zr Alloy
PublikacjaThe development of composite oxide layers on the Ti13Nb13Zr alloy, their structure and properties have been demonstrated. Two subsequent methods were applied to prepare the composite layers. During the first stage gas oxidation produced a solid oxide layer, and subsequently oxide nanotubes were produced by using an electrochemical method. Scanning electron microscopy (SEM), chemical analysis, energy dispersive X-ray spectroscopy...
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Fully Tunable Analog Biquadratic Filter for Low-Power Auditory Signal Processing in CMOS Technologies
PublikacjaA novel Gm-C structure of a second-order continuous-time filter is proposed that allows for the independent control of the filter’s natural frequency (ω0) and quality factor (Q). The structure consists of two capacitors and four transconductors. Two transconductors together with the capacitors form a lossless second-order circuit with tunable ω0. The other two transconductors form a variable gain amplifier (VGA) which realizes...
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A Study on the Effects of Cold Deformation on CMnSi Steel Structures Utilised in the Shipbuilding Industry
PublikacjaThis article analyses the effects of deformation on the structure of CMnSi steel at various deformation levels. After hot forging, the structure of CMnSi steel comprises coarse-sized alpha and pearlite particles. The average grain size of steel after forging was 100 μm. After hot rolling, the grain size gradually decreases, with the average size of the ferrite and pearlite grains measured as 60 μm. After that, CMnSi steel was...
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Conversion of waste biomass into activated carbon and evaluation of environmental consequences using life cycle assessment
PublikacjaIn this article, activated carbon was produced from Lantana camara and olive trees by H3PO4 chemical activation. The prepared activated carbons were analyzed by characterizations such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. H3PO4 is used as an activator agent to create an abundant pore...
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In-situ odd random phase electrochemical impedance spectroscopy study on the electropolymerization of pyrrole on iron in the presence of sodium salicylate – The influence of the monomer concentration
PublikacjaIn this work, the potentiostatic electropolymerization of polypyrrole (PPy) on iron in aqueous solution of sodium salicylate and pyrrole is studied in situ by odd random phase electrochemical impedance spectroscopy (ORP-EIS). The influence of the pyrrole concentration on the electrosynthesis process is investigated. The ORP-EIS technique ensures a reliable analysis of the PPy electrosynthesis on iron by means of an advanced data...
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Electronic and ionic relaxations in strontium-borate glass and glass-ceramics containing bismuth and vanadium oxides
PublikacjaThe topography, microstructure and electrical properties of strontium-borate glass and SBO glass containing bismuth and vanadium oxides, were studied. The structure was measured using X-ray diffraction (XRD), Energy Dispersive X-ray Spectrometer (EDS) and Scanning electron microscope (SEM) methods. The A.C. complex conductivity was investigated as a function of temperature and frequency. The influence of the quantity of bismuth...
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SILICA AEROGEL TOWARDS ANODES FOR LITHIUM-ION BATTERIES
PublikacjaAn increasing demand for electrochemical energy storage and conversion devices stimulates progress in research on electrode and electrolyte materials. In the field of electrodes materials, silicon is the one of the most promising anode materials for Li-ion batteries. However silicon has the drastic volume variation (around 3 times lower on extraction) during insertion and extraction of lithium ions. As an alternative, nanocomposites...
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Structural investigations of niobium-doped bioactive calcium-phosphate glass-ceramics by means of spectroscopic studies
PublikacjaSynthetic calcium-phosphate based glasses and glass-ceramics play a crucial role in the development of tissue engineering. These materials have a high biocompatibility with biological analogues, excellent ability to undergo varying degrees of resorbability and due to their non-toxicity and relatively high bioactivity they are commonly used as bone and dental implants. A substantial research effort is devoted to improve synthetic...
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Two-step synthesis of niobium doped Na–Ca–(Mg)–P–Si–O glasses
PublikacjaNiobium doped biosolubility glasses in the Na–Ca–(Mg)–P–Si–O system were prepared by using an untypical two-step synthesis route. The parent glass was melted in air atmosphere at 1350 °C followed by re-melting the glass in Nb crucible with the addition of metallic Mg/Ca powder in the nitrogen atmosphere. The second melting step was carried out at 1450–1650 °C, using an induction furnace. The topography and structure of the obtained...
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Closed-Loop Control System Design for Wireless Charging of Low-Voltage EV Batteries with Time-Delay Constraints
PublikacjaThis paper presents an inductive power transfer system on the basis of a double single- phase three-level T-type inverter and two split transmitting coils for constant current and constant voltage wireless charging of low-voltage light electric vehicle batteries with closed-loop control, considering time-delay communication constraints. An optimal control structure and a modified control strategy were chosen and implemented to...
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Evolution of magnetic and transport properties in (Cr1−xMnx)2AlC MAX-phase synthesized by arc melting technique
PublikacjaHerein we initiate a comeback to the arc melting technique to produce MAX-phase solid solutions. Bulk samples of (Cr1−xMnx)2AlC MAX-phase with X = 0, 0.025, 0.05 and 0.1 were synthesized and studied by means of X-ray diffractometry, scanning electron microscopy in combination with energy-dispersive X-ray spectroscopy. Samples were established to be homogeneous with an incorporation of Cr7C3, AlCr2 and Al2O3 secondary phases which...
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Experimental tuning of AuAg nanoalloy plasmon resonances assisted by machine learning method
PublikacjaPlasmonic nanostructures based on AuAg nanoalloys were fabricated by thermal annealing of metallic films in an argon atmosphere. The nanoalloys were chosen because they can extend the wavelength range in which plasmon resonance occurs and thus allow the design of plasmonic platforms with the desired parameters. The influence of initial fabrication parameters and experimental conditions on the formation of nanostructures was investigated....
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The structure of strontium–borate glass-ceramics containing crystalites of Bi2VO5.5. measured with X-ray diffraction and SEM methods
Dane BadawczeThe structure of strontium–borate glass-ceramics containing Bi2VO5.5 crystallites was measured by XRD and SEM.
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Curing epoxy with electrochemically synthesized Zn Fe3-O4 magnetic nanoparticles
PublikacjaCathodic electrodeposition (CED) was applied in synthesis of undoped and zinc (Zn) doped Fe3O4 nanoparticles. Changes in the lattice structure of nanoparticles were monitored using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) supported by dispersive X-ray spectrometry (EDS), and vibrating sample magnetometry (VSM). Detailed analyses explored the formation of ZnxFe3–xO4 nanoparticles with x ≈ 0.1,...
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Broadband communication solutions for maritime ITSs: Wider and faster deployment of new e-navigation services
Publikacjan its initial part, the paper presents an overview of popular technologies and systems currently developed or employed in maritime communication. These solutions are used to provide both ship-to-ship and ship-to-shore communication for the purpose of supporting specific services, often dedicated to maritime safety and e-navigation. Utility of such communication systems have been thoroughly verified over the years and their strengths...