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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublikacjaWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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Improving the procedure of probabilistic load testing design of typical bridges based on structural response similarities
PublikacjaThis paper concerns load testing of typical bridge structures performed prior to operation. In-situ tests of a two-span post-tensioned bridge loaded with three vehicles of 38-ton mass each formed the input of this study. On the basis of the results of these measurements, an advanced FEM model of the structure was developed for which the sensitivity analysis was performed for chosen uncertainty sources. Three uncorrelated random...
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Ionogel sorbent coatings for determining organophosphorus and pyrethroid insecticides in water and fresh juice samples by headspace-solid phase microextraction
PublikacjaThe sol–gel method yielded three different ionogel sorbent coatings that were obtained based on a silica material containing ionic liquids (ILs) immobilized in its pores. Two ILs, triethylsulfonium bis(trifluoromethylsulfonyl) imide [Set3][TFSI] and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide [C4C1Pip][TFSI], as well as their equimolar mixture [Set3/C4C1Pip], were used to obtain ionogel fibers. The developed...
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Miniaturization of ESPAR Antenna Using Low-Cost 3D Printing Process
PublikacjaIn this paper, the miniaturized electronically steerable parasitic array radiator (ESPAR) antenna is presented. The size reduction was obtained by embedding its active and passive elements in polylactic acid (PLA) plastic material commonly used in low-cost 3D printing. The influence of 3D printing process imperfections on the ESPAR antenna design is investigated and a simple yet effective method to...
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Organic Acids and Polyphenols Determination in Polish Wines by Ultrasound-Assisted Solvent Extraction of Porous Membrane-Packed Liquid Samples
PublikacjaIn the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described...
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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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Assessment of Wide-Sense Stationarity of an Underwater Acoustic Channel Based on a Pseudo-Random Binary Sequence Probe Signal
PublikacjaThe performances of Underwater Acoustic Communication (UAC) systems are strongly related to the specific propagation conditions of the underwater channel. Designing the physical layer of a reliable data transmission system requires a knowledge of channel characteristics in terms of the specific parameters of the stochastic model. The Wide-Sense Stationary Uncorrelated Scattering (WSSUS) assumption simplifies the stochastic description...
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A Highly Sensitive Planar Microwave Sensor for Detecting Direction and Angle of Rotation
PublikacjaThis article presents a technique based on a modified complementary split-ring resonator (CSRR) to detect angular displacement and direction of rotation with high resolution and sensitivity over a wide dynamic range. The proposed microwave planar sensor takes advantage of the asymmetry of the sensor geometry and measures the angle of rotation in terms of the change in the relative phase of the reflection coefficients. The sensor...
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Application of a commercially available derivatization instrument and commonly used reagents to HPLC on-line determination of antioxidants
PublikacjaThis study demonstrates the potential of a commercially available derivatization instrument coupled with HPLC for separation and on-line determination of antioxidants detected with widely used screening reagents - DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) or FCR (Folin-Ciocalteu's phenol reagent ). As the result of optimization, key parameters of the analytical procedure,...
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A LUMPED-CIRCUIT MODEL OF CIRCULAR PISTON TRANSDUCER FOR MODELING ITS PERFORMANCE IN DUAL FREQUENCY OPERATING MODES
PublikacjaThe paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and ra dial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. Th e approximate solution for harmonic case is represented in the form of 4x4 matrix, which is syn thesized...
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CGO FILMS ON YSZ ELECTROLYTE FABRICATED BY SPRAY PYROLYSIS FOR SOFC
PublikacjaINTRODUCTION Solid oxide fuel cells are one of the fastest developing energy converters. The advancement introduced by research community provides steady state progress is stability and performance of the fuel cells. Significant influence on the cell’s performance and stability is related to cell design. The simplest design just consists of an anode, a solid electrolyte and a cathode. However, in order to improve the properties,...
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Capillary gas chromatography using a -cyclodextrin forenantiomeric separation of methylamphetamine, its precursors andchloro intermediates after optimization of the derivatization reaction
PublikacjatThe enantiomeric ratio of methylamphetamine (MAMP) is closely related to the optical activity of precur-sors and reagents used for the synthesis and this knowledge can provide useful information concerningthe origins and synthetic methods used for illicit manufacture. The information can be utilized for reg-ulation of the precursors and investigation of the manufacturing sources but this requires analyticalprocedures to determine...
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Influence of temperature on the activity of anammox granular biomass.
PublikacjaThe aim of this study was to determine a short-term and long-term effect of temperature on the anammox rate and determination of temperature coefficients in the Arrhenius and Ratkowsky equations. The short-term effects of temperature on the anammox granular biomass were investigated in batch tests at ten different temperatures in the range of 10–55 °C. The maximum overall nitrogen removal rate of 1.3 gN gVSS−1·d−1 was observed...
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Mechanical Strength of MV Ship-switchgear During Fault Arc
PublikacjaIn the paper the analysis of pressure stressed in enclosure during fault arc inside switchgear is pre-sented as well. There is introduced the method based on determining stresses which are sum of tensile stresses (membrane) and deflection stresses. For tensile stresses nalysis the energy method, for unrestrainedly supported rectangular plate, was used. In the further part of the paper, the calculations and measurements results...
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Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
PublikacjaOne of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was...
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Variable-Fidelity Simulation Models and Sparse Gradient Updates for Cost-Efficient Optimization of Compact Antenna Input Characteristics
PublikacjaDesign of antennas for the Internet of Things (IoT) applications requires taking into account several performance figures, both electrical (e.g., impedance matching) and field (gain, radiation pattern), but also physical constraints, primarily concerning size limitation. Fulfillment of stringent specifications necessitates the development of topologically complex structures described by a large number of geometry parameters that...
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Local variability in snow concentrations of chlorinated persistent organic pollutants as a source of large uncertainty in interpreting spatial patterns at all scales
PublikacjaSingle point sampling, a widespread practice in snow studies in remote areas, due to logistical constraints, can present an unquantified error to the final study results. The low concentrations of studied chemicals, such as chlorinated persistent organic pollutants, contribute to the uncertainty. We conducted a field experiment in the Arctic to estimate the error stemming from differences in the composition of snow at short distances...
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Towards classification of patients based on surface EMG data of temporomandibular joint muscles using self-organising maps
PublikacjaThe study considers the need for an effective method of classification of patients with a temporomandibular joint disorder (TMD). The self-organising map method (SOM) was applied to group patients and used together with the cross-correlation approach to interpret the processed (rectified and smoothed by using root mean square (RMS) algorithm) surface electromyography signal (sEMG) obtained from testing the muscles (two temporal...
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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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High Isolation Metamaterial-based Dual-band MIMO Antenna for 5G Millimeter-wave Applications
PublikacjaThis article presents a high-isolation metamaterial-based dual-band multiple-input multiple-output (MIMO) antenna for 5G millimeter-wave communication networks. The proposed antenna is a pentagon-shaped monopole that provides a dual-band response with a wide operating bandwidth at 5G 28/28 bands. The antenna is printed on 0.508-mm-thick Rogers RT5880 substrate of relative permittivity ɛr =2.2. It exhibits a small physical size...
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One More Step Towards a Circular Economy for Thermal Insulation Materials—Development of Composites Highly Filled with Waste Polyurethane (PU) Foam for Potential Use in the Building Industry
PublikacjaThe rapid development of the building sector has created increased demand for novel materials and technologies, while on the other hand resulting in the generation of a severe amount of waste materials. Among these are polyurethane (PU) foams, which are commonly applied as thermal insulation materials. Their management is a serious industrial problem, due to, for example, their complex chemical composition. Although some chemical...
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Development of a new green analytical methodology for the determination of phthalates in single-use babies diapers using ultrasound-assisted extraction and polypropylene porous membrane
PublikacjaA green extraction strategy was developed and utilized for the extraction and determination of phthalates. The extraction is based on ultrasound-assisted extraction and a polypropylene porous membrane. The Box-Behnken model was performed to optimize the extraction condition. The optimal extraction conditions are 5.5 mL of ethyl acetate, 10 min of extraction time and 55 C for extraction temperature. The developed green extraction...
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Two bacterial small heat shock proteins, IbpA and IbpB, form a functional heterodimer
PublikacjaSmall heat shock proteins (sHsps) are a conserved class of ATP-independent chaperones which in stress conditions bind to unfolded protein substrates and prevent their irreversible aggregation. Substrates trapped in sHsps-containing aggregates are efficiently refolded into native structures by ATP-dependent Hsp70 and Hsp100 chaperones. Most γ-proteobacteria possess a single sHsp (IbpA), while in a subset of Enterobacterales, as...
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Increasing the conductivity of V2O5 -TeO2 glass by crystallization: structure and charge transfer studies
PublikacjaIn the present paper, V2O5-TeO2 glass...
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Interspecies distances between propionic acid degraders and methanogens in syntrophic consortia for optimal hydrogen transfer
PublikacjaA mixed culture from an anaerobic biowaste digester was enriched on propionate and used to investigate interspecies hydrogen transfer in dependence of spatial distances between propionate degraders and methanogens. From 20.3 mM propionate, 20.8 mM acetate and 15.5 mM methane were formed. Maximum specific propionate oxidation and methane formation rates were 49 and 23 mmol mg−1day−1, respectively. Propionate oxidation was inhibited by...
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Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations
PublikacjaThe present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of different mechanisms was identified by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of...
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Komu i jak z sukcesem przekazać pałeczkę? Transfer przedsiębiorstw w polskim sektorze MSP
PublikacjaTransfer biznesu jest fazą w cyklu życia biznesu, przedsiębiorstwa czy właściciela. Nie dla każdej firmy przeniesienie kończy się sukcesem. Część firm „umiera”, a zastępują je nowe, lepiej dopasowane do potrzeb gospodarki. Transfer przedsiębiorstwa trudniejszy jest w firmach mniejszych, gdzie właściciel odgrywa dominującą rolę. W monografii omówione zostaną wybrane zagadnienia związane z procesem przekazania biznesu w małych i...
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The Influence of Loop Heat Pipe Evaporator Porous Structure Parameters and Charge on Its Effectiveness for Ethanol and Water as Working Fluids
PublikacjaAbstract: This paper presents the results of experiments carried out on a specially designed experimental rig designed for the study of capillary pressure generated in the Loop Heat Pipe (LHP) evaporator. The commercially available porous structure made of sintered stainless steel constitutes the wick. Three different geometries of the porous wicks were tested, featuring the pore radius of 1, 3 and 7 um. Ethanol and water as two...
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The methods of heat recovery in air conditioning and ventilation systems
PublikacjaPrzedstawiono wybrane metody i urządzenia do odzysku ciepła takie jak: recyrkulacja, regeneratory obrotowe, rekuperatory, rurki cieplne,układy z czynnikiem pośredniczącym, pompy ciepła oraz układy hybrydowe. Przedyskutowano podstawowe kryteriium oceny odzysku ciepła oraz efektywność cieplną wymiennika w układzie odzysku ciepła.
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The effect of heat treatment of hardwood on the specific cutting resistance
PublikacjaW pracy przedstawiono wyniki badań mocy skrawania podczas przecierania modyfikowanego i niemodyfikowanego termicznie drewna dębowego i jesionowego na pilarce ramowej PRW15M. W pierwszym etapie badań, graniakowe próbki drewna dębowego i jesionowego były modyfikowane termicznie za pomocą przegrzanej pary (temperatura 197C, czas 4 h) w parzelni wysokotemperaturowej, w warunkach przemysłowych. Następnie, wyznaczono właściwe powierzchniowe...
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The effect of temperature difference on heat transport in solar cells
PublikacjaW pracy omówiono wpływ wzrostu temperatury i mechanizm transportu ciepła na drodze przewodzenia w układach hybrydowych PV/T. Wyznaczono współczynniki przewodzenia krystalicznego krzemu typu n i p oraz gęstość strumienia ciepła w zakresie temperatur od 0 do 100 st. C.
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Investigations of welded joints of dissimilar heat resistant steels.
PublikacjaPrzeprowadzono badania metalograficzne połączeń spawanych różnorodnych stali żarowytrzymałych rur o przekroju 31,8x7,1 mm ze stali 10H2M z blachą ze stali 20H23N18. Badania makro- i mikrostruktury złączy spawanych wykazały, że istotnym czynnikiem wpływającym na właściwości mechaniczne złącza jest obecność wad takich jak pory lub wtrącenia żużla. Te nieciągłości w materiale powodują koncentrację naprężeń i powstawanie mikropęknięć.
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Heat and mass exchange in the process of condensation on critical droplets.
PublikacjaSformułowano model wzrostu kropli krytycznej podając równania zmiany masy i temperatury kropli. Pokazano formę zlinearyzowaną tych równań dobrze aproksymującą wzrost kropli w poblizu wymiaru krytycznego. Podano rozwiązanie układu zlinearyzowanego uzależniając zmianę temperatury od zmiany masy kropli i czasu charakterystycznego.
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Influence of the heat treatment on corrosion characteristics of the Superston alloy
PublikacjaW artykule przedstawiono wpływ hartowania i odpuszczania na twardość i właściwości korozyjne stopu Superston, stosowanego na śruby okrętowe. Stwierdzono, iż hartowanie z temperatury 900 st.C i odpuszczanie w temperaturze 550 st.C znacząco podwyższa odporność na korozję stopu Superston w 3% roztworze NaCl w porownaniu ze stanem odlanym.
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The effect of heat exchanger geometry on adsorption chiller performance
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Thermal heat-balance mode flow-to-frequency converter
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Geothermal heating plant with a combustion engine heat pump.
PublikacjaPrzedstawiono koncepcję ciepłowni geotermalnej zagospodarowującej zasoby energii zawarte w nisko i średniotemperaturowej wodzie termalnej. W tym celu zaproponowano zastosowanie pompy grzejnej napędzanej silnikiem spalinowym.
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Selected aspects of heat recovery simulation in houseboat installations
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Heat Source Models in Numerical Simulations of Laser Welding
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Korozja rur ciepłowniczych = Heat water tubes corrosion
PublikacjaZbadano uszkodzenia korozyjne instalacji ciepłowniczej w aspekcie jakości rur zgrzewanych i korozyjności wody sieciowej. Rury przewodowe ze stali niskowęglowej zostały zniszczone przez korozję wżerową/podosadową zlokalizowaną w obszarze połączenia zgrzewanego wskutek nieodpowiedniej jakości wody.
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Zagospodarowanie ciepła odpadowego z biogazowych agregatów kogeneracyjnych w oczyszczalni ścieków = Waste heat utilisation from cogeneration set in sewage plant
PublikacjaW pracy opisano koncepcję współpracy biogazowych modułów kogeneracyjnych z niskotemperaturowym obiegiem parowym. Proponowana modernizacja pozwoliłaby na wykorzystanie entalpii fizycznej spalin, tym samym zwiększając sprawność urządzeń wytwarzających ciepło i energię elektryczną. Tego typu rozwiązanie umożliwiłoby częściowe pokrycie zapotrzebowania własnego na energię elektryczną, generując oszczędności w przedsiębiorstwie. W artykule...
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Direct QSPR: the most efficient way of predicting organic carbon/water partition coefficient (log K OC) for polyhalogenated POPs
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Direct measurements of odorous volatile organic compounds present in biosolids cakes by Proton Transfer Reaction – Mass Spectrometry Technique
PublikacjaThis paper show the results of investigation of concentration of odorous chemical compounds emitted upon ageing of anaerobically stabilised biosolids that could contribute to the overall odour character of nuisance emissions. Biosolids samples from wastewater treatment plant were collected in spring time. Concentrations of volatile organic compounds using a US EPA flux hood and Proton Transfer Reaction-Time of Flight-Mass Spectrometry...
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Comparison of Absorbed and Intercepted Fractions of PAR for Individual Trees Based on Radiative Transfer Model Simulations
PublikacjaThe fraction of absorbed photosynthetically active radiation (fAPAR) is a key parameter for estimating the gross primary production (GPP) of trees. For continuous, dense forest canopies, fAPAR, is often equated with the intercepted fraction, fIPAR. This assumption is not valid for individual trees in urban environments or parkland settings where the canopy is sparse and there are well-defined tree crown boundaries. Here, the distinction...
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Unusual fluorescence anisotropy spectra of three-component donor-mediator-acceptor systems in uniaxially stretched polymer films in the presence of energy transfer
PublikacjaW pracy analizowano transfer energii w układzie donor-mediator-akceptor w osiowo rozciąganych foliach polimerowych. Stwierdzono, że informacja zawarta w orientacji wektora pola elektrycznego wiązki światła wzbudzającego układ jest zachowana po zajściu procesu transferu energii pomiędzy molekułami w foliach rozciąganych. Natomiast w foliach nierozciąganych fluorescencja mediatora i akceptora jest bardzo silnie zdepolaryzowana.
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A new method for real-time monitoring of volatiles in frying fumes using proton transfer reaction mass spectrometry with time-of-flight analyse
PublikacjaTo safeguard the consumers’ well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled....
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Coil Design for Wireless Power Transfer with Series-Parallel Compensation
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Molecular Determinants of Proton Transfer in ATP Synthase FO Complex
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Experimental Comparison of Designed Inductance Coils for Wireless Power Transfer
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Research and Development of Inductive-Resonant Wireless Power Transfer System
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