Filtry
wszystkich: 834
-
Katalog
Wyniki wyszukiwania dla: TRIPLE-BAND ANTENNAS
-
Proton-Electron Hole Interactions in Sr(Ti,Fe)O3−δ Mixed-Conducting Perovskites
PublikacjaOxides in which total electrical conductivity is determined by the partial conductivities of three types of charge carriers i.e. holes/ electrons, oxygen ions, and protons are key components of well-functioning proton ceramic fuel cells. Apart from electrochemical properties also easily modified microstructure is an important feature of the electrodes. In the paper, a group of SrTi1−xFexO3−δ (STF, x = 0.2–0.8) perovskites prepared...
-
Analysis of magnetic field inside thin-layer ferromagnetic objects
PublikacjaResults of the numerical analysis of the magnetic field inside an infinitely long, thin-layer ferromagnetic pipe with and without a barrier were presented in this paper. Two wires with current symmetrically placed on two sides of the pipe are the sources of magnetic field. Numerical calculations for the quasi-steady state for chosen frequency band were carried out in the Flux 2D.
-
Broadband Compact Single-Layer Magic-T Junction with Separation of DC Signals between All Ports
PublikacjaA novel structure for a four-port microstrip magic-T junction is presented. The device is composed of microstrip and slotline circuits etched onto two sides of a dielectric substrate. The device is extremely compact and occupies an area more than three times smaller than similar structures recently reported in the literature. The novelty of the device lies in the use of microstrip/slotline transitions for both input ports: summation...
-
A novel luminescent chemical sensor for the determination of Pb 2+ and Cu 2+ ions
PublikacjaSilica xerogel surface grafted with aminopropyl (PrNH2) groups was additionally treated by cetyltrimethylammonium bromide (CTAB) surfactant and ascorbic acid (asc) in alkaline solution. This material symbolized as SiO2-PrNH2-CTAB/asc, proved to be a stable luminescent material, exhibited an emission band peaked at 393 nm under excitation wavelength 335 nm. Time evolution of the band intensity suggests changes of defect concentration...
-
Frequency-Reconfigurable Hybrid SIW-Based Self-Diplexing Antenna Using Solid and Liquid Dielectric Loading
PublikacjaThis paper presents a novel frequencyreconfigurable self-diplexing antenna (SDA) utilizing a hybrid substrate-integrated waveguide (SIW). The antenna comprises a radiating slot, a feeding network, and a hybrid SIW cavity featuring half-mode circular and half-mode rectangular SIW structures. The unique feature of this antenna lies in its fine-tuning capability of each resonant frequency by inserting or injecting solid and liquid...
-
A facile method for Tauc exponent and corresponding electronic transitions determination in semiconductors directly from UV–Vis spectroscopy data
PublikacjaIn this work, a facile method allowing for estimation of the exponent in the Tauc equation directly from the UV–vis spectra is presented. It is based on the Taylor expansion of the logarithmic version of the Tauc equation. The Tauc exponent is calculated from the tangent slope of the absorption data. Knowledge of this coefficient provides information about the optical transition types and is used as an input for the calculations...
-
Secure Quaternion Feistel Cipher for DICOM Images
PublikacjaAn improved and extended version of a quaternion-based lossless encryption technique for digital image and communication on medicine (DICOM) images is proposed. We highlight and address several security flaws present in the previous version of the algorithm originally proposed by Dzwonkowski et al. (2015). The newly proposed secure quater- nion Feistel cipher (S-QFC) algorithm...
-
On Inadequacy of Sequential Design of Experiments for Performance-Driven Surrogate Modeling of Antenna Input Characteristics
PublikacjaDesign of contemporary antennas necessarily involves electromagnetic (EM) simulation tools. Their employment is imperative to ensure evaluation reliability but also to carry out the design process itself, especially, the adjustment of antenna dimensions. For the latter, traditionally used parameter sweeping is more and more often replaced by rigorous numerical optimization, which entails considerable computational expenses, sometimes...
-
Influence of accelerometer signal pre-processing and classification method on human activity recognition
PublikacjaA study of data pre-processing influence on accelerometer-based human activity recognition algorithms is presented. The frequency band used to filter-out the accelerometer signals and the number of accelerometers involved were considered in terms of their influence on the recognition accuracy. In the test four methods of classification were used: support vector machine, decision trees, neural network, k-nearest neighbor.
-
RECENT ADVANCES IN GRAPHENE APPLICATION FOR ELECTRONIC SENSING
PublikacjaThe great interest in graphene is caused by its potential for constructing various sensors exhibiting excellent parameters. The high carrier mobility and the unique band structure of graphene makes it promising especially in the field-effect transistors (GFET) applications. In this article, recent advances of the selected graphene-based sensor applications were presented and the possible directions for further investigations were...
-
Detection of the Direct Sequence Spread Spectrum Signals with BPSK Modulation
PublikacjaThis paper presents a method of the DS CDMA signals with BPSK modulation detection through the examination of the enhanced signal spectrum density. On the base of experiments carried out on the real radio communication signals the impact of a narrowband emission occurring in the examined frequency band on the detection process effectiveness was shown. The results of the experiment aimed at the detection of the satellite navigation...
-
Design of OFDM-based radio communication systems for coast-to-sea and coast-to-air propagation environments
PublikacjaIn the paper the study of radio communication system design process for systems based on OFDM transmission is considered. The signal propagation model for 1.4 GHz frequency band is discussed, and the study of signal propagation characteristics, important from the point of view of OFDM system design, is presented. The methodology of OFDM interface design is proposed and some characteristics of the OFDM-based radio communication...
-
System Loss Model for Body-to-Body Networks in Indoor and Outdoor Environments
PublikacjaA system loss model for body-to-body networks in indoor and outdoor environments is proposed in this paper, based on measurements taken at 2.45 GHz. The influence of the type of environment, antenna visibility and user mobility on model parameters has been investigated. A significant impact of mutual antennas’ placement and their visibility is shown. The proposed model fits well to empirical data, with the average root mean square...
-
Highly Visible-Light-Photoactive Heterojunction Based on TiO2 Nanotubes Decorated by Pt Nanoparticles and Bi2S3 Quantum Dots
PublikacjaA heterojunction with excellent visible light response and stability based on titanium dioxide nanotubes (TiO2 NTs), bismuth sulfide quantum dots (Bi2S3 QDs), and platinum nanoparticles (Pt NPs) is proposed. Both Pt NPs (3.0 ± 0.2 nm) and Bi2S3 QDs (3.50 ± 0.20 nm) are well distributed on the (i) top parts, (ii) inner walls, and (iii) outer walls of the TiO2 NTs. Visible-light-induced photoreaction was initialized by excitation...
-
High frequency dynamics of an isotropic Timoshenko periodic beam by the use of the Time-domain Spectral Finite Element Method
PublikacjaIn this work results of numerical simulations and experimental measurements related to the high frequency dynamics of an aluminium Timoshenko periodic beam are presented. It was assumed by the authors that the source of beam structural periodicity comes from periodical alterations to its geometry due to the presence of appropriately arranged drill-holes. As a consequence of these alterations dynamic characteristics of the beam...
-
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...
-
Interference aware bluetooth scatternet (re)configuration algorithm IBLUERA
PublikacjaThis paper presents a new algorithm IBLUEREA, which enables reconfiguration of Bluetooth scatternet to reduce interference. IBLUEREA makes use of the complex model comparing ISM environment efficiency. The mechanism envisages the use of the assessment of the probability of successful (unsuccessful) frame transmission in order to take a decision concerning co-existence of technologies which make use of the same ISM band (here Bluetooth...
-
Compact antenna array comprising fractal-shaped microstripradiators
PublikacjaA design method of antenna array consisting of eight microstrip patches modified with Sierpinski fractal curves has been presented andexperimentally validated in this paper. Method proposed has enabled the achievement of considerable miniaturization of array length (26%),together with multi-band behavior of the antenna, which proves the attractiveness of presented design methodology and its ability to be implemented in more complex...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 75 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 65 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 90 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 80 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 45 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 35 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 50 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 70 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapasitor with the use of ZnO coated microsphere-based fiber-optic sensor - 30 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 60 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 40 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 85 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Temperature measurement of supercapacitor with the use of ZnO coated microsphere-based fiber-optic sensor - 55 Celsius degrees
Dane BadawczeApplication of a microsphere-based fiber-optic sensor with 200 nm zinc oxide (ZnO) coating, deposited by Atomic Layer Deposition (ALD) method, for temperature measurements of supercapasitor, is presented. Internal temperature of the supercapacitor is investigated in the range between 30°C and 90°C. The supercapacitor temperature was investigated using...
-
Analysis of the chemical composition of MnO-B2O3 glass
Dane BadawczeStructural and thermal properties of xMnO−(100−x)B2O3 (where x = 40, 50 and 60 mol%) glass samples have been investigated with the employment of various techniques. Fourier transform infrared spectroscopy results revealed the influence of MnO on glass matrix. Decrease of B–O bond-related band intensities has been observed. MnO addition was found to...
-
INNOVATIVE THERMODYNAMICAL CYCLES BASED ON ENHANCEMENT MASS, MOMENTUM, ENTROPY AND ELECTRICITY TRANSPORT DUE TO SLIP, MOBILITY, TRANSPIRATION, ENTROPY AND ELECTRIC JUMPS AS WELL AS OTHER NANO-FLOWS PHENOMENA
PublikacjaIn our work, a further development of the authors model of thermo-chemical flow of fuel, air, oxygen, steam water, species, ionic and electron currents within nano channels and nano-structures of novel devices is presented. Different transport enhancement models are taken into account -among them the most important are: the velocity slip connected with complex external friction, the Darcy mobility and the Reynolds transpiration....
-
Straightening of ship hull structure made of 316L stainless steel - tensile test of water cooled materia
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - tensile test of reference material materia (transverse direction)
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - tensile test of reference material materia (longitudinal direction)
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - microstructure of naturally colled material
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - microstructure of water cooled material
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - microstructure of reference material
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Straightening of ship hull structure made of 316L stainless steel - tensile test of naturally cooled material
Dane BadawczeThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
-
Photovoltaic bulk heterojunctions with interpenetrating network based on semiconducting polymers
PublikacjaPhotovoltaic cells are supposed to be the most common generators of useful electricity in the nearest future as they utilize inexhaustible carriers of renewable energy called photons. Despite the fact that 95% of worldwide applied photovoltaic devices are based on inorganic semiconductors the area of organic photovoltaics grows successively due to possibility of considerable reduction of manufacturing costs. Since the Heeger's...
-
Spectroscopic and photophysical properties of ZNTPP in a room temperature ionic liquid
PublikacjaThe steady-state absorption and emission spectra and the time-resolved Soret- and Q-band excited fluorescence profiles of the model metalloporphyrin, ZnTPP, have been measured in a highly purified sample of the common room temperature ionic liquid, [bmim][PF(6)]. S(2)-S(0) emission resulting from Soret-band excitation behaves in a manner completely consistent with that of molecular solvents of the same polarizability. The ionic...
-
Circular polarization diversity implementation for correlation reduction in wideband low-cost multiple-input-multiple-output antenna
PublikacjaIn this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three parallel coplanar ground planes, and two feedlines in-between. For circular polarization (CP), quasi-loops are created by etching slots on the outermost ground planes. With this...
-
Synthesis and hydrogen evolving catalysis of a panchromatic photochemical molecular device
PublikacjaA dinuclear hydrogen evolution photocatalyst [(tbbpy)2Os(tpphz)PtI2](PF6)2 (tbbpy = 4,4′-tert-butyl-2,2′-bipyridine; tpphz = tetrapyrido[3,2-a:2′,3′-c:2′′,3′′-h:2′′′,3′′′-j]phenazine) is synthesized in order to make use of the broader range of visible light absorption mitigated by the osmium center. In a first step, the activity of the complex for hydrogen evolution is investigated by evaluating the role of different electron donors...
-
Identification of hydroacoustic wave sources of ship in motion
PublikacjaThis paper deals with results of identification tests of acoustic field spectrum of underwater noise generated by ship in motion. The field is connected with acoustic activity of ship mechanisms and devices in operation. Vibration energy generated by the mechanisms and devices is transferred through ship structural elements to surrounding water where it propagates in the form of acoustic waves of a broad band of frequencies. In...
-
Characterization of slow and fast fading in off-body communication at 2.45 GHz with space diversity scheme in indoor environment
PublikacjaThe characterization of slow and fast fading in Wireless Body Area Networks with space diversity scheme has been presented. The analysis, based on the measurements at 2.45 GHz in indoor environment, has shown that for all investigated configurations of receiving wearable antennas the correlation coefficient values of received signals’ parameters are below the assumed value of 0.5, being close to zero for the vast majority of cases. It...
-
Analysis of degaussing process of ferromagnetic objects
PublikacjaResults of the analytical and numerical analysis of the degaussing process phenomena of ferromagnetic objects were presented in this paper. The screening effectiveness of the electromagnetic field of magnetic screens in most cases depends on thickness, conductivity, magnetic permeability of the screen and angular frequency of degaussing currents. The magnetic field inside thin-layer ferromagnetic object was presented in this paper....
-
Kinetics of Cross-Linking Reaction of Epoxy Resin with Hydroxyapatite-Functionalized Layered Double Hydroxides
PublikacjaThe cure kinetics analysis of thermoset polymer composites gives useful information about their properties. In this work, two types of layered double hydroxide (LDH) consisting of Mg2+ and Zn2+ as divalent metal ions and CO32− as an anion intercalating agent were synthesized and functionalized with hydroxyapatite (HA) to make a potential thermal resistant nanocomposite. The curing potential of the synthesized nanoplatelets in the...
-
Temperature influence on tyre/road noise frequency spectra
PublikacjaThe correction for temperature effect on measured tyre/road noise is very important as it may be one of the main sources of errors in measurement results due to substantial influence of this parameter on obtained values. The latest version of the Technical Specification ISO/CD TS 13471-1 about Temperature Corrections contains a proposal of correction procedure for normalizing measured noise levels to a reference air temperature...
-
Linking optical and electronic properties to photoresponse of heterojunctions based on titania nanotubes and chromium, molybdenum, and tungsten oxides
PublikacjaThe development of photosensitization strategies for titanium dioxide is necessary for the enhancement of its optical and electronic properties towards its application potential in solar photoelectrochemistry. In this work, significant differences in the photosensitizing capability of the 6th group transition metal oxides applied on the surface of titania nanotubes are reported. For the first time, correlations between the experimentally...