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Search results for: low-noise preamplifiers
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Problems of the starting and operating of hydraulic components and systems in low ambient temperature (Part II)
PublicationPodczas rozruchu zespołów hydraulicznych w warunkach szoku termicznego dochodzi do dynamicznej zmiany wymiarów elementów tych zespołów. Odkształcenia elementów powodują zmianę efektywnego luzu między współpracującymi elementami. Na zmiany luzu ma pływ między innymi: różnica temperatur pomiędzy gorącym olejem a zimnym zespołem hydraulicznym, natężeniem przepływu czynnika roboczego, konstrukcji zespołu, rodzaju materiału i kształtu...
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Determination of ability of machines with hydraulic drive during start-up in low ambient temperatures
PublicationW artykule przedstawiono sposoby określania zdatności maszyn z napędem hydraulicznym podczas rozruchu w niskich temperaturach otoczenia. Przedstawiono wyniki badań eksperymentalnych i symulacji komputerowej nagrzewania się układów maszyny roboczych i zespołów hydraulicznych podczas rozruchu w warunkach szoku termicznego.
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Low-Field NMR Study of Shortcake Biscuits with Cricket Powder, and Their Nutritional and Physical Characteristics
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Low Field NMR Studies of Wheat Bread Enriched with Potato Juice During Staling
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Damage to Model DNA Fragments from Very Low-Energy (<1 eV) Electrons
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Chemistry induced by low-energy electrons in condensed multilayers of pure small organic acids
PublicationPrzedstawiono reakcje indukowane przez niskoenergetyczne elektrony (0.7 - 20 eV) w kondensowanych warstwach kwasu mrówkowego (HCOOH), częściowo deuterowanego kwasu octowego (CH3COOD) oraz kwasu trifluorooctowego (CF3COOD).
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Problems of the starting and operating of hydraulic components and systems in low ambient temperature (Part I)
PublicationW artykule przestawnie są problemy rozruchu i działania zespołów i układów hydraulicznych w niskich temperaturach otoczenia. Z tych powodów autor przebadał hydrauliczne zespoły i układy w warunkach szoku termicznego (oziębione zespoły zasilano gorącym czynnikiem roboczym). Określono parametry rozruchu w tych warunkach kilku zespołów oraz układów hydraulicznych, przy których ich eksploatacja jest bezpieczna. Badania eksperymentalne...
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Speed observer of induction machine based on backstepping and sliding mode for low‐speed operation
PublicationThis paper presents a speed observer design based on backstepping and slidingmode approaches. The inputs to the observer are the stator current and thevoltage vector components. This observer structure is extended to the integra-tors. The observer stabilizing functions contain the appropriate sliding surfaceswhich result from the Lyapunov function. The rotor angular speed is obtainedfrom the non‐adaptive formula with a sliding...
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Waste tire rubber as low-cost and environmentally-friendly modifier in thermoset polymers – a review
PublicationNowadays, waste tire rubber (WTR) management is a growing and serious problem. Therefore, research works focused on the development of cost-effective and environmentally-friendly methods of WTR recycling are fully justified. Incorporation of WTR into polymer matrices and composite materials attracts much attention, because this approach allows sustainable development of industrially applicable waste tires recycling technologies....
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Low-Loss Mechanically Tunable Resonator and Phase Shifters in Groove Gap Waveguide Technology
PublicationThis research is focused on the design and realization of high-performance high-power variable phase shifters in groove gap waveguide technology. Specifically, it is shown that the unique characteristic of groove gap waveguides, which is its proper operation without the need for electrical connection between the top and bottom sections of the waveguide, can be used to design mechanically tunable devices. Using the proposed method,...
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Microemulsion Delivery Systems with Low Surfactant Concentrations: Optimization of Structure and Properties by Glycol Cosurfactants
PublicationExtensive use of microemulsions as delivery systems raises interest in the safe ingredients that can form such systems. Here, we assessed the use of two glycols, i.e., propylene glycol and pentylene glycol, and their mixtures to manipulate the properties and structure of microemulsions. Obtained systems with glycols were extensively characterized in terms of capacity to incorporate water phase, droplet size, polydispersity, structure...
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Normalized Partial Scattering Cross Section for Performance Evaluation of Low-Observability Scattering Structures
PublicationThe development of diffusion metasurfaces created new opportunities to elevate the stealthiness of combat aircraft. Despite the potential significance of metasurfaces, their rigorous design methodologies are still lacking, especially in the context of meticulous control over the scattering of electromagnetic (EM) waves through geometry parameter tuning. Another practical issue is insufficiency of the existing performance metrics,...
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Low temperature removal of SO2 traces from air by MgO-loaded porous carbons
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Blood pressure and low-density lipoprotein-cholesterol lowering for prevention of strokes and cognitive decline
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Hydrothermal dewatering of low-rank coals: Influence on the properties and combustion characteristics of the solid products
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Influence of hydrothermal treatment on selenium emission-reduction and transformation from low-ranked coal
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Microstructural evolution of 6061 aluminium alloy subjected to static and dynamic compression at low temperature
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In situ insight into the low-temperature promotion of ZIF-67 in electrocatalytic oxygen evolution reaction
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Low-temperature synthesis of zeolite from perlite waste — Part II: characteristics of the products
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Low temperature CVD growth of graphene nano-flakes directly on high K dielectrics
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Universal Modular Permanent Magnet Synchronous Generator for Small Low-Head Hydropower Plants
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Fiber - optic low-coherence tomography system for visualization of internal structure of ceramic materials
PublicationW artykule przedstawiono światłowodowy system dwuwymiarowej wizualizacji niejednorodnych struktur warstw ceramicznych. Omówiono projekt i fizyczną realizację układu wykorzystującego optyczną, niskokoherentną reflektometrię optyczną, która umożliwia niedestrukcyjne obrazowanie wewnętrznych struktur różnych materiałów. W pracy przedstawiono przykładowe wyniki pomiarów wewnętrznych warstw LSFO.
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublicationIn 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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Domain segmentation for low-cost surrogate-assisted multi-objective design optimisation of antennas
PublicationAbstract: Information regarding the best possible design trade-offs of an antenna structure can be obtained through multiobjective optimisation (MO). Unfortunately, MO is extremely challenging if full-wave electromagnetic (EM) simulation models are used for performance evaluation. Yet, for the majority of contemporary antennas, EM analysis is the only tool that ensures reliability. This study introduces a procedure for accelerated...
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Low cost real time UAV stereo photogrammetry modelling technique – accuracy considerations
PublicationThe paper presents accuracy considerations regarding three 3D modelling techniques. The tested new consumer type stereo camera (ZED 3D Stereolabs) has been implemented info an aerial mapping system, on board micro air vehicle MAV) and tested object has been mapped using a real-time photogrammetry with original real-time software application. The evaluated results has been compared with model gained with a state of art unmanned...
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Design and optimization of a novel miniaturized low-profile circularly polarized wide-slot antenna
PublicationThis paper presents a novel structure of a compact circularly polarized (CP) antenna. CP is obtained using a parasitic quasi-rectangular strip placed coplanar to the feedline. A ground plane perturbation combined with the asymmetric geometry of the coplanar waveguide ground planes is utilized to excite additional CP modes. All antenna dimensions are rigorously optimized to achieve the best possible performance in terms of the impedance...
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Low-energy electron scattering from molecular hydrogen: Excitation of the X1Σg+ to b3Σu+ transition
PublicationWe present time-of-flight differential cross-section measurements and convergent close-coupling calculations of differential cross sections for the electron-impact excitation of the X 1 g + → b 3 u + transition in molecular hydrogen. A part of this work was recently published [M. Zawadzki et al., Phys. Rev. A 97, 050702(R) (2018)]. In this work, agreement between theory and experiment is excellent overall, and marks a transition...
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A new viscoelastic method of calculation of low-temperature thermal stresses in asphalt layers of pavements
PublicationThe paper presents a new method of calculation of thermal stresses in asphalt layers of pavements induced by cooling or heating. The method, developed by the author, is based on the analytical solution for the linear viscoelastic Burgers model extended numerically for the case of asphalt layers whose rheological parameters are strongly dependent on temperature. The coefficient of thermal expansion and Poisson’s ratio may optionally...
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The effect of low energy impact on the tensile strength of coated and uncoated glass particulate composites.
PublicationPrzedstawiono model teoretyczny pozwalający przewidywać poudarową wytrzymałość na rozciąganie w funkcji parametrów materiałowych i budowy kompozytu. Określono eksperymentalnie poudarową wytrzymałość na ściskanie kompozytów zbrojonych ciągłym włóknem szklanym w osnowie żywicy epoksydowej napełnianej mikrokulkami szklanymi w celu obniżenia skłonności do powstawania dużych zniszczeń przy udarze o niskiej energii. Wyniki eksperymentalnie...
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Random components influence on the values characterising periodic disturbances in low voltage supply lines.
PublicationAnalizowano wpływ składowych losowych na wielkości charakteryzujących zaburzenia okresowe w napięciu zasilania na przykładzie współczynnika zawartości harmonicznych (THD). Zaprezentowano sposób wyznaczania niepewności pomiaru współczynnika THD, uwzględniający występowanie korelacji pomiędzy składową podstawową i kolejnymi harmonicznymi napięcia sieci a także między poszczególnymi harmonicznymi. Przedstawiono analizę wyników z pomiarów...
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1.2V low-power four-quadrant CMOS transconductance multiplier operating in saturation region.
PublicationW pracy opisano niskomocową strukturę układową liniowego transkonduktancyjnego mnożnika czteroćwiartkowego pracującego w zakresie nasycenia. Układ analizowano z uwzględnieniem standardowego 0,35-mikrometrowego procesu CMOS. Przeprowadzone symulacje przy pomocy programu SPICE wykazały wysoką liniowość w odniesieniu do obu wejść sterujących X, Y. Np. dla sygnału harmonicznego 1 MHz; 0,3Vp-p na wejściu Y uzyskano zniekształcenia...
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MPEG-7-based low level descriptor effectiveness in the automatic musical sound classification.
PublicationCelem referatu jest określenie, które z parametrów opisowych MPEG-7 są najbardziej przydatne w klasyfikacji dźwięków instrumentów muzycznych. Określana jest wysokość dźwięku a następnie wyznaczane są wartości parametrów zawartych w standardzie MPEG-7. Otrzymany wektor parametrów poddawany jest analizie statystycznej w celu wyeliminowania danych nadmiarowych. Do celów automatycznej klasyfikacji i testów zaprojektowano dwa systemy...
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Degradation and damage of advanced polymer composites due to environmental effects and low velocity impact
PublicationPrzedstawiono zagadnienie wpływu srodowiska wody oraz niskoenergetycznego udaru na właściwości mechaniczne laminatów epoksydowych wzmocnionych włóknami węglowymi, szklanymi, aramidowymi i hybrydowymi. Na tle krótkiego przeglądu literatury na dany temat przedstawiono oryginalne wyniki badań eksperymentalnych autorki.
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Indoor Air Quality and Thermal Comfort in Naturally Ventilated Low-Energy Residential Houses
PublicationRozdział omawia jakość powietrza i termiczny komfort w naturalnie wentylowanych energooszczędnych budynkach mieszkalnych. Obliczenia wykonano metoda elementów skończonych dla wentylacji naturalnej. Uwzględniono 2 różne położenia wlotów powietrza oraz system grzewczy kaloryferowy i podłogowy. Wyniki MES porównano z doświadczeniami.
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Power grid frequency measurement in LabVIEW environment using the least mean squares method to signal phase approximation in the presence of noise
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A new B-D-galactosidase with a low temperature optimum isolated from the Antarctic Arthrobacter sp. 20B: gene cloning, purification and characterization.
PublicationA psychrotrophic bacterium producing a coldadaptedB-galactosidase upon growth at low temperatureswas classiWed as Arthrobacter sp. 20B. A genomic DNAlibrary of strain 20B introduced into Escherichia coliTOP10F' and screening on X-Gal (5-bromo-4-chloro-3-indolyl-B-D-galactopyranoside)-containing agar plates ledto the isolation of B-galactosidase gene. The B-galactosidasegene (bgaS) encoding a protein of 1,053 amino acids,with a...
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Joint experimental and theoretical study on low-energy elastic electron scattering by gaseous alkynes: Differential cross sections, shape resonances, and methylation effects
PublicationA detailed comparison of experimental and theoretical elastic cross sections for low-energy electron scattering by ethyne, taken earlier in our group by Gauf et al. [Phys. Rev. A 87, 012710 (2013)], and some of its methylated derivatives, propyne, and the isomers 1-butyne and 2-butyne, taken here, are presented. The present differential cross sections were measured at incident electron energies ranging from 1 eV to 30 eV and...
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Low-power microwave-induced fabrication of functionalised few-layer black phosphorus electrodes: A novel route towards Haemophilus Influenzae pathogen biosensing devices
PublicationIn this paper, various passivation schemes were applied at few-layer black phosphorus (FLBP) to achieve covalent functionalisation with 4-azidobenzoic acid, improving its electrochemical response intended for analytical and biosensing applications. The thermal and microwave assisted modification procedures in toluene and dime-thylformamide resulted in high reversibility of reactions on functionalised FLBP using a ferricyanide/ferrocya-nide...
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Statistical Data Pre-Processing and Time Series Incorporation for High-Efficacy Calibration of Low-Cost NO2 Sensor Using Machine Learning
PublicationAir pollution stands as a significant modern-day challenge impacting life quality, the environment, and the economy. It comprises various pollutants like gases, particulate matter, biological molecules, and more, stemming from sources such as vehicle emissions, industrial operations, agriculture, and natural events. Nitrogen dioxide (NO2), among these harmful gases, is notably prevalent in densely populated urban regions. Given...
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Trajecta: relgie, cultuur and society in de Nederlanden / religion, culture and society in the Low Countries
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Electrochromic foil-based devices: optical transmittance and modulation range, effect of ultraviolet irradiation,and quality assessment by 1/f current noise
PublicationPrzedstawiono technologię wytwarzania elementów wykazujących zjawisko elektrochromizmu - zmiany transmitancji optycznej pod wpływem gromadzenia ładunku. Pokazano, że zastosowanie warstwy odbijającej może poprawić stopień zmian transmitancji optycznej. Ponadto, pokazano, że zjawiska losowe generujące szum typu 1/f w tych elementach może być wykorzystane do oceny ich jakości.
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Experimental study of the fuel jet combustion in high temperature and low oxygen content exhaust gases
PublicationPrzeprowadzono badania eksperymentalne spalania pojedynczego strumienia paliwa gazowego. Paliwo podawano współosiowo do generowanych przez konwencjonalny palnik gazowy spalin o wysokiej temperaturze i niskiej zawartości tlenu. Badano wpływ zawartości tlenu w utleniaczu na widzialność płomienia i skład produktów spalania.
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Low-Barrier Hydrogen Bond Determines Target-Binding Affinity and Specificity of the Antitubercular Drug Bedaquiline
PublicationThe role of short strong hydrogen bonds (SSHB) in ligand-target binding remains largely unexplored, thereby hin- dering a potentially important avenue in the rational drug de- sign. Here, we investigate the interaction between bedaquiline (Bq), a potent anti-tuberculosis drug, and the mycobacterial ATP synthase, to unravel the role of a specific hydrogen bond to a conserved acidic residue in the target affinity and specificity....
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Harnessing digital technologies for poverty reduction. Evidence for low-income and lower-middle income countries
PublicationThis paper contributes to understanding the relationship between ICT deployment and poverty alleviation in developing countries. It assess the digital technologies contribution to poverty reduction, through different channels of impact, like education, labor market, income and ICTtrade related activities. Using the sample of 40 developing countries between 1990 and 2019, it relies on macro data extracted from the World Bank Development...
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Fracture Areas Quantitative Investigating of Bending-Torsion Fatigued Low-Alloy High-Strength Steel
PublicationIn this study, the impact of pseudo-random non-proportional bending-torsion fatigue loadings proportion on the fatigue life and the fracture surface topography was analyzed. Investigation was carried out for 24 specimens made of S355J2 steel with 11 different ratios of maximum stresses λ. For these cases, after the fatigue tests, the surface topography measurements were carried out using an optical profilometer, using the focus...
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Machine-Learning-Powered EM-Based Framework for Efficient and Reliable Design of Low Scattering Metasurfaces
PublicationPopularity of metasurfaces has been continuously growing due to their attractive properties including the ability to effectively manipulate electromagnetic (EM) waves. Metasurfaces comprise optimized geometries of unit cells arranged as a periodic lattice to obtain a desired EM response. One of their emerging application areas is the stealth technology, in particular, realization of radar cross section (RCS) reduction. Despite...
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Low-dose radiation accelerates aging of the T-cell receptor repertoire in CBA/Ca mice
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<title>An optical low-coherence system for 2-dimensional visualization of thin polymer layers</title>
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High-order compact difference algorithm on half-staggered meshes for low Mach number flows
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Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC
PublicationW pracy przedstawiono możliwość dogrzewu obiegu ORC za pomocą pary upustowej.