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Improved Bandwidth of Microstrip Wide-Slot Antenna Using Gielis Curves
PublikacjaThe development of a broadband printed wide-slot antenna based on Gielis curves is presented in this article. The printed wide-slot antenna can be conveniently reshaped to achieve ultra-wideband performance by using superformula. The distinct advantage of employing the superformula in design of wide-slot antenna lies in its ability to define nearly any geometric shape including non-standard, complex and non-intuitive for the wide-slot...
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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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Szyk planarny anten mikropaskowych z przeznaczeniem do radaru dopplerowskiego
Publikacjaw pracy opisano konstrukcję oraz wyniki pomiarów szyku 4 anten mikropaskowych w postaci macierzy 2x2 na częstotliwość 10 ghz, z przeznaczeniem do pracy w układzie radaru dopplerowskiego. pojedynczym promiennikiem w omawianym szyku jest antena mikropaskowa, zasilana przez sprzężenie elektromagnetyczne realizowane przez szczelinę we wspólnym ekranie. wykorzystanie szyku w układzie radaru dopplera stwarza wymagania w stosunku do charakterystyk...
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Characteristics of the Polarised Off-Body Channel in Indoor Environments
PublikacjaThis paper addresses the depolarisation effect in off-body Body Area Networks channels, based on measurements performed at 2.45 GHz in an indoor environment. Seven different scenarios, involving both static and dynamic users, were considered, taking a statistical perspective. The analysis of the cross-polarisation discrimination is performed, as well as the analysis of path loss in co- and cross-polarised channels. Results show...
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Characteristics of the polarised off-body channel in indoor environments
PublikacjaThis paper addresses the depolarisation effect in off-body body area networks channels, based on measurements performed at 2.45 GHz in an indoor environment. Seven different scenarios, involving both static and dynamic users, were considered, taking a statistical perspective. The analysis of the cross-polarisation discrimination is performed, as well as the analysis of path loss in co- and cross-polarised channels. Results show...
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A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublikacjaIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
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Influence of User Mobility and Antenna Placement on System Loss in B2B Networks
PublikacjaIn this paper, the influence of user mobility and on-body antenna placement on system loss in body-to-body communications in indoor and outdoor environments and different mobility scenarios is studied, based on system loss measurements at 2.45 GHz. The novelty of this work lies on the proposal of a classification model to characterise the effect of user mobility and path visibility on system loss, allowing to identify the best...
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Fast Fading Characterization for Body Area Networks in Circular Metallic Indoor Environments
PublikacjaWith the increasing development of 5G and Body Area Network based systems being implemented in unusual environments, propagation inside metallic structures is a key aspect to characterize propagation effects inside ships and other similar environments, mostly composed of metallic walls. In this paper, indoor propagation inside circular metallic structures is addressed and fast fading statistical distributions parameters are obtained...
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Miniaturized Inline Bandpass Filters Based on Triple-Mode Integrated Coaxial-Waveguide Resonators
PublikacjaThis work presents a design technique to implement miniaturized cross-coupled bandpass filters in inline physical configurations based on triple-mode resonators. Triple-mode resonances are obtained by using integrated coaxial-waveguide cavity resonators. They consist of two coaxial conducting posts placed in the sidewalls of a rectangular waveguide cavity. In the proposed triplet, a transmission zero (TZ) can be positioned at any...
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Dual-Polarized Wideband Bandpass Metasurface-Based Filter
PublikacjaThis paper presents a novel metasurface-based bandpass filter. The structure is realized by simply patterning a double-sided AD250 substrate, and does not require any vias or insertion of lumped elements. The top layer is an annular- aperture-array with multiple inner conductors, whereas the bottom layer is a first-order Hilbert-curve array. FEM-based simulation results of the filter are obtained using HFSS. The experimental validation...
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Kogeneracja gazowa w nowych uwarunkowaniach po implementacji dyrektywy europejskiej
PublikacjaOmówiono krajowe uregulowania dotyczące obowiązku zakupu energii elektrycznej wytwarzanej w skojarzeniu z wytwarzaniem ciepła. Przeanalizowano mechanizm obrotu świadectwami pochodzenia energii. Omówiono preferencje przyjęte dla wsparcia małych układów skojarzonych wykorzystujących jako paliwo gaz ziemny.
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High Frequency Harmonics Emission of Modern Power Electronic AC-DC Converters
PublikacjaModern AC/DC converters with bidirectional power flow employing PWM boost topology generate harmonic distortions of input current in relatively high frequency range tightly related to modulation carrier frequency. These frequencies and its multiples in typical applications are usually located in frequency range from single up to several of kHz. Increased harmonic emission in this frequency range can easily and harmfully influence...
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Attempt to a Video-Transmission Capability in MV Mine Cable Network Using BPL-PLC Technology
PublikacjaThis article presents and discusses the attempt to transmit video content using the BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It includes simulation results of a specially developed digital transmitter and receiver, dedicated to a given predefined 6 kV mining power cable. The effect of two different transmission modes (2-7 MHz and 3-7.5 MHz) and two types of coupling (capacitive-inductive and induction-inductive),...
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The Influence of Thin Gold Electrodes on the High-Temperature Impedance of Oxide Glasses
PublikacjaThe influence of thin gold electrodes on the electrical measurements of glasses at high temperatures was studied using impedance spectroscopy. The impedance was measured several times over a wide frequency range from 10 mHz to 1 MHz and the temperature ranged from 213 to 673 K under air and nitrogen atmospheres. The results showed a drop in the conductivity of more than an order of magnitude at a temperature around 603 K during...
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Determination of eight artificial sweeteners and common Stevia rebaudiana glycosides in non-alcoholic and alcoholic beverages by reversed-phase liquid chromatography coupled with tandem mass spectrometry.
PublikacjaThe method for the determination of acesulfame-K, saccharine, cyclamate, aspartame, sucralose, alitame, neohesperidin dihydrochalcone, neotame and five common steviol glycosides (rebaudioside A, rebaudioside C, steviol, steviolbioside and stevioside) in soft and alcoholic beverages was developed using high-performance liquid chromatography and tandem mass spectrometry with electrospray ionisation (HPLC-ESI-MS/MS). To the best of...
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Effect of the Catalytic Center on the Electron Transfer Dynamics in Hydrogen-Evolving Ruthenium-Based Photocatalysts Investigated by Theoretical Calculations
PublikacjaThe light-induced relaxation pathways in the molecular photocatalyst [(tbbpy)2Ru(tpphz)PtCl2]2+ are investigated with time-dependent density functional theory calculations together with the Marcus theory of electron transfer (ET). The calculations show that metal (Ru) to ligand (tpphz) charge transfer (MLCT) triplet states are populated following an excitation in the longer wavelength range of the absorption spectrum, but that an...
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Oznaczanie stężeń jonów fluorkowych w próbkach wody pitnej z terenu miasta Malborka = Determination of fluoride ions in drinking water samples collected from the area of the town of Malbork
PublikacjaW pracy przedstawiono badania próbek wody pitnej z terenu miasta Malborka. Próbki wody pobierano sześciokrotnie (w miesięcznych odstępach - październik 2008, listopad 2008, grudzień 2008, styczeń 2009, luty 2009 oraz marzec 2009) w siedmiu punktach leżących w głównych dzielnicach miasta Malborka. Pobrane próbki podano analizie w celu oznaczenia następujących parametrów: zawartość anionów: F-, Cl-, Br-, 2NO , 3NO , 34 PO , 24 SO...
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Scalability of surrogate-assisted multi-objective optimization of antenna structures exploiting variable-fidelity electromagnetic simulation models
PublikacjaMulti-objective optimization of antenna structures is a challenging task due to high-computational cost of evaluating the design objectives as well as large number of adjustable parameters. Design speedup can be achieved by means of surrogate-based optimization techniques. In particular, a combination of variable-fidelity electromagnetic (EM) simulations, design space reduction techniques, response surface approximation (RSA) models,...
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Impact of Cultivation Conditions, Ethylene Treatment, and Postharvest Storage on Selected Quality and Bioactivity Parameters of Kiwifruit “Hayward” Evaluated by Analytical and Chemometric Methods
PublikacjaOrganic, semiorganic, and conventional “Hayward” kiwifruits, treated with ethylene for 24 h and stored during 10 days, were assessed by UV spectrometry, fluorometry, and chemometrical analysis for changes in selected characteristics of quality (firmness, dry matter and soluble solid contents, pH, and acidity) and bioactivity (concentration of polyphenols via Folin-Ciocalteu and p-hydroxybenzoic acid assays). All of the monitored...
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"Creating a numerical model of noise conditions based on the analysis of traffic volume changes in cities with low and medium structure.
PublikacjaThe subject of this research study is to analyze noise conditions of the selected area in the city of Gdańsk using data related to traffic volume changes during a day. This is because daily distribution of noise levels is much more helpful for noise control and reduction than traditional maps with Lden levels indicated. Calculations are made with the use of a numerical model developed at the Gdansk Univ. of Technology and implemented...
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"Creating a numerical model of noise conditions based on the analysis of traffic volume changes in cities with low and medium structure.
PublikacjaThe subject of this research study is to analyze noise conditions of the selected area in the city of Gdańsk using data related to traffic volume changes during a day. This is because daily distribution of noise levels is much more helpful for noise control and reduction than traditional maps with Lden levels indicated. Calculations are made with the use of a numerical model developed at the Gdansk Univ. of Technology and implemented...
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The Hydrolysis of Slowly Biodegradable Substrate in Activated Sludge
PublikacjaIn a present work a novel procedure, based on the standard batch tests and pretreatment of wastewater sample with coagulation-flocculation method, was proposed to evaluate the effects of hydrolysis of slowly biodegradable substrate (Xs) on biological nutrient removal (BNR) processes in activated sludge systems. The study was conducted at two large BNR wastewater treatment plants (WWTPs) in northern Poland: "Wschod" in Gdansk and...
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Subjective Quality Evaluation of Speech Signals Transmitted via BPL-PLC Wired System
PublikacjaThe broadband over power line – power line communication (BPL-PLC) cable is resistant to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency. These features make it an ideal solution for delivering data, e.g. in an underground mine environment, especially clear and easily understandable voice messages. This paper describes a subjective quality evaluation of...
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Zastosowanie nowatorskich materiałów geosyntetycznych w konstrukcjach oporowych z gruntu zbrojonego
PublikacjaW artykule przedstawiono metodę projektowania stromych skarp wznoszonych z gruntów słabo przepuszczalnych, zbrojonych geosiatkami drenującymi. Z analiz przeprowadzonych dla gruntów o różnej wodoprzepuszczalności oraz dla różnej geometrii skarpy wynika, że pionowy rozstaw i długość zbrojenia mają istotne znaczenie dla stateczności skarpy. Dla gruntów słabo przepuszczalnych, o typowych wartościach współczynników ściśliwości objętościowej...
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Working Conditions in Global Value Chains: Evidence for European Employees
PublikacjaThis article investigates a sample of almost nine million workers from 24 European countries in 2014 to conclude how involvement in global value chains (GVCs) affects working conditions. We use employer–employee data from the Structure of Earnings Survey merged with industry-level statistics on GVCs based on the World Input-Output Database. Given the multidimensional nature of the dependent variable, we compare estimates of the...
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Material Identification of the Human Abdominal Wall Based On the Isogeometric Shell Model
PublikacjaThe human abdominal wall is an object of interest to the research community in the context of ventral hernia repair. Computer models require a priori knowledge of constitutive parameters in order to establish its mechanical response. In this work, the Finite Element Model Updating (FEMU) method is used to identify an heterogeneous shear modulus distribution for a human abdominal wall model, which is based on nonlinear isogeometric...
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Does being socially good save firms from bankruptcy? A systematic literature review and bibliometric analysis
PublikacjaThe purpose of the review was to find out, does being responsible saves firms from bank-ruptcy? What is the relationship between corporate social responsibility and default risk? What meth-ods and measures are used in the literature to evaluate this relationship? And what is the theoretical underpinning of the studies? Moreover, to explore what are the gaps for future work, Web of Science and Scopus databases were utilised to obtain...
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Niskonapięciowy filtr analogowy CMOS wykorzystujący konwerter ujemnoimpedancyjny
PublikacjaA low-voltage 3-order low-pass CMOS filter based on the novel current inversion type negative impedance converter (CNIC) is presented. It shows a badwidth of 10 MHz at 400 uW power consumption and 2 V supply voltage when realized in a 0.35 um CMOS process.
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Niskonapięciowy filtr analogowy CMOS oparty o konwerter ujemno-impedancyjny
PublikacjaA low-voltage 3-order low-pass CMOS filter based on the novel current inversion type negative impedance converter (CNIC) is presented. It shows a badwidth of 10 MHz at 400 uW power consumption and 2 V supply voltage when realized in a 0.35 um CMOS process.
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Using On-line Measurement by Electronic Nose and Computer Simulations for Real-time Control at WWTP
PublikacjaContinuous investigation of wastewater quality can be carried out by a device called an e-nose. One important feature of the proposed real-time control system for WWTP is that using on-line measurements by e-nose together (Figure 1) with technological sets picked on this basis by means of computer models, it is possible to change treatment process parameters, depending on the current quality of wastewater. It can be used for the...
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Sprzętowa implementacja transformacji Hougha w czasie rzeczywistym
PublikacjaW artykule przedstawiono implementację sprzętową w FPGA algorytmu do wykrywania kształtów aproksymowanych zbiorem linii prostych podczas przetwarzania obrazu cyfrowego w czasie rzeczywistym. W opracowanej strukturze sprzętowej podniesiono efektywność przetwarzania poprzez zastosowanie przetwarzania przepływowego, lookup table, wykorzystanie wyłącznie arytmetyki liczb całkowitych oraz rozproszenie pamięci głosowania. Eksperymentalnie...
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New devices to capture the temperature effect under dynamic compression and impact perforation of polymers, application to PMMA
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Typing of Scopulariopsis and Microascus fungi by Random Amplified Polymorphic DNA (RAPD)
PublikacjaOBJECTIVES Scopulariopsis species and their teleomorphs of the genus Microascus are commonly isolated from soil, decaying plant material and indoor environments. Moreover, certain Scopulariopsis and Microascus species are recognised as opportunistic human pathogens. Although most species can be identified by detailed morphological study, phenotypic characters appear to overlap in several cases and morphology seems to be insufficient...
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The cement-bone bond is weaker than cement-cement bond in cement-in-cement revision arthroplasty. A comparative biomechanical study
PublikacjaThis study compares the strength of the native bone-cement bond and the old-new cement bond under cyclic loading, using third generation cementing technique, rasping and contamination of the surface of the old cement with biological tissue. The possible advantages of additional drilling of the cement surface is also taken into account. Femoral heads from 21 patients who underwent a total hip arthroplasty performed for hip arthritis...
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Multifrequency Wideband Sonar Array
PublikacjaThis paper describes of new approach to Multifrequency Wideband Arrays (MWA),applied piezocomposite technologies of the array elements. MWA operating in transmitting(Tx) and receiving (Rx) mode on two or three bands, requires state-of-the-art technology andefficient array designing than conventional array in which separate arrays for every band oreven separate Tx and Rx transducers/arrays are used. The new piezocomposite elements...
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Mechanism of hopping conduction in Be–Fe–Al–Te–O semiconducting glasses and glass–ceramics
PublikacjaElectrical properties of beryllium-alumino-tellurite glasses and glass–ceramics doped with iron ions were studied using impedance spectroscopy. The conductivity was measured over a wide frequency range from 10 mHz to 1 MHz and the temperature range from 213 to 473 K. The D.C. conductivity values showed a correlation with the Fe-ion concentration and ratio of iron ions on different valence states in the samples. On the basis of...
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A 0.5 V Nanowatt Biquadratic Low-Pass Filter with Tunable Quality Factor for Electronic Cochlea Applications
PublikacjaA novel implementation of an analogue low-power, second-order, low-pass filter with tunable quality factor (Q) is presented and discussed. The filter feature is a relatively simple, buffer-based, circuit network consisting of eleven transistors operating in a subthreshold region. Q tuning is accomplished by injecting direct current into a network node, which changes the output resistance of the transistors and, as a result, modifies...
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High-conducting Bi4V2-xFexO11-δ ceramics containing Fe2O3 nanocrystals: Structure and properties
PublikacjaThe topography, structure, thermal, magnetic, and electrical properties of Bi4V2-xFexO11-δ ceramics substituted with x = 0.5 and 0.7 Fe were studied. The microscope analysis showed the presence of iron-rich nanocrystals formed on the Bi-Fe-V-O grains. The X-ray diffraction studies confirmed that grains are built mostly of tetragonal Bi4V1.5Fe0.5O10.5 phase. Thermal properties analysis showed an order-disorder type γ ↔ γʹ phase...
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Low-cost and reliable geometry scaling of compact microstrip couplers with respect to operating frequency, power split ratio, and dielectric substrate parameters
PublikacjaA technique for rapid re-design of miniaturised microstrip couplers with respect to operating conditions as well as material parameters of the dielectric substrate is proposed. The dimension scaling process is based on a set of pre-optimised reference designs, obtained for an equivalent circuit model of the coupler at hand. The reference designs are utilised to construct an inverse surrogate model which – upon suitable correction...
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A Low-Profile 3-D Printable Metastructure for Performance Improvement of Aperture Antennas
PublikacjaIn order to increase the radiation performance of aperture-type antennas, this paper demonstrates a low-profile, planar, single-layer, three-dimensional (3-D) printable metastructure. The proposed hybridized metastructure is highly transparent as it is made out of novel hybrid meta-atoms having transmission coefficient magnitudes greater than -0.72 dB and fully complies with the near-field phase transformation principle. The hybridized...
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Hydrogen production from ethanol In nitrogen microwave plasma At atmospheric pressure
PublikacjaHydrogen seems to be one of the most promising alternative energy sources. It is a renewable fuel as it could be produced from e.g. waste or bio-ethanol. Furthermore hydrogen is compatible with fuel cells and is environmentally clean. In contrast to conventional methods of hydrogen production such as water electrolysis or coal gasification we propose a method based on atmospheric pressure microwave plasma. In this paper we present...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Cost-Efficient Design Methodology for Compact Rat-Race Couplers
PublikacjaIn this article, a reliable and low-cost design methodology for simulation-driven optimization of miniaturized rat-race couplers (RRCs) is presented. We exploit a two-stage design approach, where a composite structure (a basic building block of the RRC structure) is first optimized using a pattern search algorithm, and, subsequently, the entire coupler is tuned by means of surrogate-based optimization (SBO) procedure. SBO is executed...
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Inline Waveguide Filter With Transmission Zeros Using a Modified-T-Shaped-Post Coupling Inverter
PublikacjaThis letter reports the design techniques for a class 2 of inline waveguide bandpass filters with sharp-rejection capabil3 ities at the lower stopband based on a novel nonlinear-frequency4 variant-coupling (NFVC) structure. The proposed NFVC consists 5 of a modified-T-shaped metallic post (MTP) that is placed at the 6 center of the waveguide broad wall with its open arms lying 7 along the waveguide width. The engineered NFVC structure 8...
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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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Algorytmy hybrydowe optymalizacji w zastosowaniu do problemu sterowania systemami dystrybucji wody
PublikacjaW pracy analizowany jest problem optymalizującego zintegrowanego sterowania ilością i jakością w systemach dystrybucji wody. Proponowane decyzje i sterowania powinny zapewniać optymalizację przyjętego wskaźnika jakości, przy spełnieniu ograniczeń właściwych tej klasie systemów. Ostatecznie do rozwiązania złożonych zadań optymalizacji dynamicznej zaproponowane zostało podejście hybrydowe, wspomagające predykcyjne algorytmy sterowania...
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Usefulness of the PCR technique for bacterial DNA detection in blood of the patients after ''oppened heart'' operations.
PublikacjaOperacje kardiochirurgiczne w krążeniu pozaustrojowym (KPU) poprzez ogromny uraz, powodowanie występowania zaburzeń odporności oraz uszkodzenie barier anatomicznych stwarzają sytuację wybitnie sprzyjającą rozwojowi powikłań infekcyjnych u tych chorych. Prowadzenie terapii antybiotykowej profilaktycznej i leczniczej, a także selektywna dekontaminacja przewodu pokarmowego może utrudniać i przedłużać czas rozpoznania obecności bakterii...
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At what temperature should the tire rolling resistance be measured?
PublikacjaThe climate crisis is already an indisputable fact and therefore, it is necessary to reduce energy consumption, and especially energy wasting. One of the ways to reduce energy consumption of motor vehicles is to decrease vehicle movement resistance, including rolling resistance. In order for the optimization of tire rolling resistance to be efficient, it is necessary to apply appropriate optimization criteria that are closely related...
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New concept of drilling auger for displacement pile installation
PublikacjaIn 2020, a new version of the screw displacement auger for pile installation in soil was developed and patented in Poland. It was named DPDT (Displacement Pile Drilling Tool). The general aim of its development was to reduce the soil resistances to the auger during screwing into the ground while maintaning a good load-bearing capacity for the screw displacement piles. The “DPDT-Auger” prototype was tested as a scaled-down model...