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Wyniki wyszukiwania dla: BIO-INSPIRED ANTENNAS
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Rapid EM-driven antenna dimension scaling through inverse modeling
PublikacjaIn this letter, a computationally feasible technique for dimension scaling of antenna structures is introduced. The proposed methodology is based on inverse surrogate modeling where the geometry parameters of the antenna structure of interest are explicitly related to the operating frequency. The surrogate model is identified based on a few antenna designs optimized for selected reference frequencies. For the sake of computational...
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Single-Anchor Indoor Localization Using ESPAR Antenna
PublikacjaIn this paper a new single-anchor indoor localization concept employing Electronically Steerable Parasitic Array Radiator (ESPAR) antenna has been proposed. The new concept uses a simple fingerprinting algorithm adopted to work with directional main beam and narrow minimum radiation patterns of ESPAR antenna that scans 360° area around the base station, while the signal strength received from a mobile terminal is being recorded...
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublikacjaIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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Simple 2-D Direction-of-Arrival Estimation Using an ESPAR Antenna
PublikacjaIn this letter, it has been shown how an electronically steerable parasitic array radiator (ESPAR) antenna can be used for 2-D direction-of-arrival (DoA) estimation employing received signal strength (RSS) values only. The proposed approach relies on changes in RSS values recorded at the antenna output port observed for different vertical and horizontal directions, while antenna’s main beam sweeps 360° area around the ESPAR antenna. Based...
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Pareto Ranking Bisection Algorithm for Expedited Multi-Objective Optimization of Antenna Structures
PublikacjaThe purpose of this letter is introduction of a novel methodology for expedited multi-objective design of antenna structures. The key component of the presented approach is fast identification of the initial representation of the Pareto front (i.e., a set of design representing the best possible trade-offs between conflicting objectives) using a Pareto-ranking bisection algorithm. The algorithm finds a discrete set of Pareto-optimal...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublikacjaDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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A Simple-Topology Compact Broadband Circularly Polarized Antenna With Unidirectional Radiation Pattern
PublikacjaIn this letter, a geometrically simple, reflector-backed single-point-fed circularly polarized (CP) antenna with unidirectional radiation pattern is presented. The structure comprises a simple coplanar waveguide (CPW) feeding circuit with an open slot etched on one side of the coplanar ground. The enhanced CP bandwidth is obtained by combining the loop mode, the slot mode, and the asymmetrical configuration of the coplanar ground...
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A Compact Circularly Polarized Antenna With Directional Pattern for Wearable Off-Body Communications
PublikacjaThis letter presents a geometrically simple and compact circularly polarized (CP) antenna with unidirectional radiation characteristics for off-body communications. The proposed antenna is based on a microstrip line monopole extension from a coplanar waveguide (CPW) and a protruded stub from one side of the coplanar ground plane along the length of the monopole. The orthogonal components of equal amplitudes required for circular...
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Design and Optimization of Metamaterial-Based Dual-Band 28/38 GHz 5G MIMO Antenna with Modified Ground for Isolation and Bandwidth Improvement
PublikacjaThis letter presents a high-isolation dual-band multiple-input multiple-output (MIMO) antenna based on the ground plane modification and optimized metamaterials (MMs) for 5G millimeter-wave applications. The antenna is a monopole providing a dual-band response at 5G 28/38 bands with a small physical size (4.8 × 2.9 × 0.762 mm3, excluding the feeding line). The MIMO consists of two symmetric radiating elements arranged adjacently...
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Design and experimental verification of multi-layer waveguide using pin/hole structure
PublikacjaThis study presents a novel technique for minimizing RF leakage in metallic hollow waveguides fabricated using the multilayer split-block method. By integrating a pin/hole wall into the split-block multilayers, a substantial reduction of RF leakage can be achieved while reducing the circuit size and mitigating the performance variations. To validate the proposed approach, a slot antenna fed by single ridge waveguide has been prototyped...
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Design and Characterization of a Planar Structure Wideband Millimeter-Wave Antenna with Wide Beamwidth for Wearable off-body Communication Applications
PublikacjaThis letter presents the design of a planar single-layer wideband antenna featuring wide beamwidth has well as high and stable in-band gain. The proposed antenna is a planar monopole fed by a bottom-grounded coplanar waveguide to realize wide beamwidth in both the xz- and yz-planes. Simultaneous optimization of all adjustable antenna parameters, carried out at the full-wave electromagnetic simulation level. The constructive interference...
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High-Gain Compact Circularly Polarized X-Band Superstrate Antenna for CubeSat Applications
PublikacjaIn this letter, a concept of high-gain circularly polarized X-band antenna employing a partially reflecting surface (PRS) has been presented. In the initial antenna analysis, the influence of parasitic elements size in the PRS structure on antenna radiation pattern parameters has been investigated and the optimal arrangement of the elements has been identified. The proposed antenna provides wide bandwidth of return loss above 10...
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Two-Row ESPAR Antenna with Simple Elevation and Azimuth Beam Switching
PublikacjaIn this letter, we propose a two-row electronically steerable parasitic array radiator (ESPAR) antenna designed for direction of arrival (DoA) estimation in Internet of Things (IoT) applications relying on simple microcontrollers. The antenna is capable of elevation and azimuth beam switching using a simple microcontroller-oriented steering circuit and provides 18 directional radiation patterns, which can be grouped in 3 distinctive...
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A Note on Fractional Curl Operator
PublikacjaIn this letter, we demonstrate that the fractional curl operator, widely used in electromagnetics since 1998, is essentially a rotation operation of components of the complex Riemann–Silberstein vector representing the electromagnetic field. It occurs that after the wave decomposition into circular polarisations, the standard duality rotation with the angle depending on the fractional order is applied to the left-handed basis vector...
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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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A Series-Inclined-Slot-Fed Circularly Polarized Antenna for 5G 28-GHz Applications
PublikacjaThis letter presents the design of a single-point-fed, geometrically simple circularly polarized (CP) antenna for 28 GHz Ka-band applications. The proposed antenna is based on a straight microstrip line printed on one side and coupled with the nearly square patches through a 45-degree inclined V-shape slot aperture on the other side. In order to generate circular polarization, the fundamental radiating mode is degenerated at a...
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Methods of data extraction from sub-bottom profiler's signal
PublikacjaData obtain during sounding Gdansk Bay with SES-2000 Standard parametric sub-bottom profiler has two types of information: envelope and pure signal. First is used to plot echograms in real time and contain envelope of echo. The second one is stored during sounding and can be processed after recording data. Comparison of results will be shown and discussed. First step in investigation was proper configuration of small measurement...
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Expedited optimization of antenna input characteristics with adaptive Broyden updates
PublikacjaSimulation-driven adjustment of geometry and/or material parameters is a necessary step in the design of contemporary antenna structures. Due to their topological complexity, other means, such as supervised parameter sweeping, does not usually lead to satisfactory results. On the other hand, rigorous numerical optimization is computationally expensive due to a high cost of underlying full-wave electromagnetic (EM) analyses, otherwise...
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Time-Gating method with automatic calibration for accurate measurements of electrically small antenna radiation patterns in Non-Anechoic environments
PublikacjaNon-anechoic sites represent a cheap alternative to measurements of antennas in dedicated facilities. However, due to a high noise—from the external EM signal sources and multipath interferences—the quality of radiation patterns obtained in non-anechoic conditions is poor. The characteristics can be corrected using a time-gating method (TGM), which involves filtering of the noise based on temporal analysis of the measured signals....
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On geometry parameterization for simulation-driven design closure of antenna structures
PublikacjaFull-wave electromagnetic (EM) simulation tools have become ubiquitous in antenna design, especially final tuning of geometry parameters. From the reliability standpoint, the recommended realization of EM-driven design is through rigorous numerical optimization. It is a challenging endeavor with the major issues related to the high computational cost of the process, but also the necessity of handling several objectives and constraints...
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Magnetic switching of Kerker scattering in spherical microresonators
PublikacjaMagneto-optical materials have become a key tool in functional nanophotonics, mainly due to their ability to offer active tuning between two different operational states in subwavelength structures. In the long-wavelength limit, such states may be considered as the directional forward- and back-scattering operations, due to the interplay between magnetic and electric dipolar modes, which act as equivalent Huygens sources. In this...
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Using creative approaches for discovering biomorphic forms for appropriate human habitation in natural environments. Case study of Kashubian Lake District
PublikacjaThe research process consisted of studies of natural and cultural conditions of the Kashubian Lake District This is an area of exceptional natural conditions. For centuries, it has seen human habitation with respect to landscape values. Given its extensive forest cover and the lack of heterogeneity of natural conditions, the area has become an interesting inspiration for the author’s original project. The project is aimed at searching...
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Constrained multi-objective optimization of compact microwave circuits by design triangulation and pareto front interpolation
PublikacjaDevelopment of microwave components is an inherently multi-objective task. This is especially pertinent to the design closure stage, i.e., final adjustment of geometry and/or material parameters carried out to improve the electrical performance of the system. The design goals are often conflicting so that the improvement of one normally leads to a degradation of others. Compact microwave passives constitute a representative case:...
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Establishing the allosteric mechanism in CRISPR‐Cas9
PublikacjaAllostery is a fundamental property of proteins, which regulates biochemical information transfer between spatially distant sites. Here, we report on the critical role of molecular dynamics (MD) simulations in discovering the mechanism of allosteric communication within CRISPR‐Cas9, a leading genome editing machinery with enormous promises for medicine and biotechnology. MD revealed how allostery intervenes during at least three...
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What should we know when choosing feather, blood, egg or preen oil as biological samples for contaminants detection? A non-lethal approach to bird sampling for PCBs, OCPs, PBDEs and PFASs
PublikacjaBirds are considered as good bio-monitors and they can provide highly valuable data about the level of contamination in their habitat. During the design of biomonitoring studies one of the first issues after choosing species is the choice of biological material. Non-lethally collected samples have recently been gaining greater attention as they offer several ethical and practical advantages. However, not all sample matrices are...
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Synthesis and characterization of novel renewable polyesters based on 2,5-furandicarboxylic acid and 2,3-butanediol
PublikacjaNovel polyesters from 2,5-furandicarboxylic acid or 2,5-dimethyl-furandicarboxylate and 2,3-butanediol have been synthesized via bulk polycondensation catalyzed by titanium (IV) n-butoxide, tin (IV) ethylhexanoate, or zirconium (IV) butoxide. The polymers were analyzed by size exclusion chromatography, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser ionization-desorption...
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Demulgowanie jako efektywna technika rozdzielania stosowana w procesach oczyszczania ścieków przemysłowych
PublikacjaOczyszczanie ścieków przemysłowych ma na celu, z reguły kilku-etapową, redukcję ładunku zanieczyszczeń na drodze procesów fizycznych, chemicznych i biologicznych. W przypadku odprowadzania strumienia ścieków poza zakład, parametry ścieków muszą spełniać normy określające dopuszczalny poziom zanieczyszczeń organicznych i nieorganicznych w ściekach. Duże znaczenie w bilansie ekonomicznym oczyszczania ścieków ma dobór procesów wstępnego...
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Biopolyols obtained via microwave-assisted liquefaction of lignin: structure, rheological, physical and thermal properties
PublikacjaThe present study examined the application of polyols obtained via microwave-assisted liquefaction of lignin in the production of rigid polyurethane foam. Lignin was liquefed in crude glycerol and 1,4-butanediol at diferent temperatures (130–170 °C), without a catalyst and using various biomass concentrations (15 and 30 wt%). The physicochemical properties, process yield, and FTIR-based identifcation of the obtained polyols were...
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Preconcentration and Analytical Methods for Determination of Methyl Tert-Butyl Ether and Other Fuel Oxygenates and Their Degradation Products in Environment: A Review
PublikacjaFuel oxygenates (FOs) are mainly ethers or alcohols which are added to gasoline either to boost the octane number or to make the fuel burning process more "cleaner" with increasing the oxygen content, or to obtain a combination of both effects. FOs are water soluble with high mobility in the environment which presence even at very low concentrations lower the quality of water making it unsafe or unpleasant due to their objectionable...
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Techno‐economic evaluation of a natural deep eutectic solvent‐based biorefinery: Exploring different design scenarios
PublikacjaThis paper presents a comprehensive techno‐economic evaluation of an integrated natural deep eutectic solvent (NADES)‐based biorefinery – a 1 ton day−1 capacity design plant. The key parameters include payback period, net present value (NPV), and internal rate of return (IRR). These were compared with the parameters of conventional biorefineries. The ‘n th plant’ results clearly revealed that the single product‐based biorefinery...
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Extractive detoxification of feedstocks for the production of biofuels using new hydrophobic deep eutectic solvents – Experimental and theoretical studies
PublikacjaThe paper presents a synthesis of novel hydrophobic deep eutectic solvents (DESs) composed of natural components, which were used for removal of furfural (FF) and 5-hydroxymethylfurfural (HMF) from lignocellulosic hydrolysates. The main physicochemical properties of DESs were determined, followed by explanation of the DES formation mechanism, using 1H NMR, 13C NMR and FT-IR analysis and density functional theory (DFT). The most...
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Fading Modelling in Dynamic Off-Body Channels
PublikacjaThis paper presents an off-body fading channel model for Body Area Networks (BANs) in indoor environments. The proposed model, which is based on both simulations and measurements in a realistic environment, consists of three components: mean path loss, body shadowing, and multipath fading. Seven scenarios in an indoor environment (a medium-size room with furniture, mostly consisting of wooden tables and chairs) have been measured:...
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Analysis of circular polarization antenna design trade‐offs using low‐cost EM‐driven multiobjective optimization
PublikacjaCircular polarization (CP) antennas are vital components of modern communication systems. Their design involves handling several requirements such as low reflection and axial ratio (AR) within the frequency range of interest. Small size is an important criterion for antenna mobility which is normally achieved as a by‐product of performance‐oriented modifications of the structure topology. In this work, multiobjective optimization...
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Expedited Design Closure of Antenna Input Characteristics by Trust Region Gradient Search and Principal Component Analysis
PublikacjaOptimization-based parameter tuning has become an inherent part of contemporary antenna design process. For the sake of reliability, it is typically conducted at the level of full-wave electromagnetic (EM) simulation models. This may incur considerable computational expenses depending on the cost of an individual EM analysis, the number of adjustable variables, the type of task (local, global, single-/multi-objective optimization),...
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Asymmetrical-Slot Antenna with Enhanced Gain for Dual-Band Applications
PublikacjaDual-band operation is an important feature of antennas to be applied in modern communication systems. Although high gain of radiators is rarely of concern in urban areas with densely located broadcasting stations, it becomes crucial for systems operating in more remote environments. In this work, a dual-band antenna with enhanced bandwidth is proposed. The structure consists of a driven element in the form of an asymmetrical radiator/slot...
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An Innovative Antenna Array with High Inter Element Isolation for Sub-6 GHz 5G MIMO Communication Systems
PublikacjaA novel technique is shown to improve the isolation between radiators in antenna arrays. The proposed technique suppresses the surface-wave propagation and reduces substrate loss thereby enhancing the overall performance of the array. This is achieved without affecting the antenna’s footprint. The proposed approach is demonstrated on a four-element array for 5G MIMO applications. Each radiating element in the array is constituted...
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Metody elektrochemiczne w zastosowaniach biomedycznych 2022/2023
Kursy OnlinePRZEDMIOT OBEJMUJE: WYKŁAD, LABORATORIUM, PROJEKT Treści wykładu Podstawy elektrochemii, elektryczna warstwa podwójna metal /elektrolit, półprzewodnik elektrolit. Kinetykaprocesów elektrodowych. Elektrokataliza. Podstawy metod pomiarowych: woltamperometria,chronoamperometria, elektrochemiczna spektroskopia impedancyjna. Wykorzystanie metodelektrochemicznych w projektowaniu sensorów w zastosowaniach biomedycznych. Biokompatybilnośćmateriałów...
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Sonocatalytic degradation of tetracycline antibiotic using zinc oxide nanostructures loaded on nano-cellulose from waste straw as nanosonocatalyst
PublikacjaThe aim of the present investigation was the combination of ZnO nanostructures with nano-cellulose (NC) for the efficient degradation of tetracycline (TC) antibiotic under ultrasonic irradiation. The removal efficiency of 12.8% was obtained by the sole use of ultrasound (US), while the removal efficiency increased up to 70% by the US/ZnO treatment process. Due to the integration of ZnO nanostructures with NC, the removal efficiency...
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Development of a simple biogas analyzer module (BAM) for real-time biogas production monitoring
PublikacjaAnaerobic digestion (AD) relies on the cooperation of specific microbial communities, making it susceptible to process disruptions that could impact biogas production. In this regard, this study presents a technological solution based on the Arduino platform, in the form of a simple online monitoring system that can track the produced biogas profile, named as biogas analyzer module (BAM). The applicability of the BAM focused on...
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Ekologiczna sanitacja. Część II – rozdział i zagospodarowanie ścieków żółtych
PublikacjaW ostatnich latach zaobserwować można coraz większe zainteresowanie sanitacją ekologiczną. Dzięki ekologicznej sanitacji odpady bytowe są usuwane i ponownie poddane zagospodarowaniu, przy całkowitym zapewnieniu odpowiednich warunków higienicznych oraz odzysku substancji odżywczych. Ten niedrogi i łatwy w użytkowaniu sposób stanowi alternatywę tradycyjnej kanalizacji „end-of-pipe”. Jednym z rozwiązań sanitacji ekologicznej jest...
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The influence of plant protection by effective microorganisms on the content of bioactive phytochemicals in apples
PublikacjaThe phytochemicals of two apple cultivars (Yellow Transparent and Early Geneva) protected in two ways, conventionally with chemical pesticides or by effective microorganisms (EM), were compared. Two types of components were determined: lipids synthesised constitutively and generated via inducible pathways polyphenols along with antioxidant activity and profiles. The antioxidant activities assessed with ABTS, DPPH and Folin–Ciocalteu...
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Investigation of Thermoplastic Polyurethanes Synthesized via Two Different Prepolymers
PublikacjaThe man aim of this work was to investigate the effect of the molecular weight of polyols, mixture of prepolymers, and [NCO]/[OH] molar ratio used during the prepolymer chain extending step on the chemical structure, thermomechanical and mechanical properties, and thermal stability of thermoplastic poly(ether-urethane)s In this work thermoplastic poly(ether-urethane)s were synthesized by using polyols with a various molecular weight,...
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Colloidal transport of lipid digesta in human and porcine small intestinal mucus
PublikacjaSmall intestinal mucus transport of food-derived particulates has not been extensively studied, despite mucus being a barrier nutrients need to cross before absorption. We used complex dispersions of digesta obtained from simulated, dynamic gastrointestinal digestion of yogurt to examine the penetrability of human and porcine mucus to the particles formed of lipolysis products. Quantitative, time-lapse confocal microscopy revealed...
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Betaine and L-carnitine ester bromides: Synthesis and comparative study of their thermal behaviour and surface activity
PublikacjaSix esters of both betaine and L-carnitine bromides, featuring alkyl groups ranging from C8 to C18 in length, have been synthesized. The thermal behaviour of these twelve bio-based salts has been analyzed and compared by thermal gravimetric analysis and differential scanning calorimetry. The L-carnitine alkyl ester bromides melted below 100 C and can hence be considered ionic liquids (ILs) with full rights. Conversely, the betaine...
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ENVIRONMENTALLY FRIENDLY MATERIALS IN ARCHITECTURE � MODERN TRENDS AND DEVELOPMENT DIRECTIONS
PublikacjaFor a long time the interest in environmentally friendly materials in architecture is no longer limited to the use of renewable and natural substances such as wood, stone, straw, or reusable materials, such as metals or glass. Today the so-called naturals and the materials compatible with the idea of sustainability constantly appear on the market in new forms. Increasing awareness of the necessity to limit the building sector’s...
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Closed Form Constraint Equations Used to Express Frictionless Slip of Multibody Systems Attached to Finite Elements—Application to a Contact between a Double Pendulum and a Beam
PublikacjaThis paper focuses on the numerical modeling of the dynamics of mechanical systems. Robots that can inspect high-voltage lines inspired this research. Their control systems must anticipate potential grab positions appropriately. We intend to formulate equations dedicated to the numerical description of the robot/cable contact. The investigated problem is not straightforward, since parts of the modeled systems are numerically inhomogeneous....
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Identification of defected sensors in an array of amperometric gas sensors
PublikacjaPurpose Amperometric gas sensors are commonly used in air quality monitoring in long-term measurements. Baseline shift of sensor responses and power failure may occur over time, which is an obstacle for reliable operation of the entire system. The purpose of this study is to check the possibility of using PCA method to detect defected samples, identify faulty sensor and correct the responses of the sensor identified as faulty. Design/methodology/approach In...
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Wpływ bezhalogenowych związków zmniejszających palność na strukturę komórkową i współczynnik tłumienia naprężeń sztywnych bio-pianek poliuretanowych
ProjektyProjekt realizowany w Katedra Technologii Polimerów zgodnie z porozumieniem DEC- 2018/02/X/ST5/02784 z dnia 2019-03-01
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Simple Superstrate Antenna for Connectivity Improvement in Precision Farming Applications
PublikacjaIn this paper, a concept of a simple circularly polarized antenna with partially reflecting surface (PRS) has been adopted for precision farming applications. The investigation contains an analysis of the dependence of the antenna performance on the elements number in the PRS structure in X- and Ka-band frequencies. Especially meaningful parameters from point-to-point connectivity perspective are...
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The supramolecular organization of self-assembling chlorosomal bacteriochlorophyll c, d, or e mimics
PublikacjaBacteriochlorophylls (BChls) c, d, and e are the main light-harvesting pigments of green photosynthetic bacteria that self-assemble into nanostructures within the chlorosomes forming the most efficient antennas of photosynthetic organisms. All previous models of the chlorosomal antennae, which are quite controversially discussed because no single crystals could be grown so far from these organelles, involve a strong hydrogen-bonding...