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Search results for: ceramika tlenkowa
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Development of a Planar LTCC GRIN Lens for 60 GHz Open-Ended Waveguide Antenna
PublicationThis study deals with the design, realization and evaluation of a gradient index lens (GRIN) made of low-temperature cofired ceramic (LTCC) for millimeter-wave communication systems at a frequency of 60 GHz. The LTCC GRIN lens presented here utilizes a radial refractive index profile achieved by varying the dielectric properties within the LTCC structure by punching 100 µm holes in the green LTCC sheets. We present the optimization...
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Electromagnetic forced vibrations of composite nanoplates using nonlocal strain gradient theory
PublicationThis article is intended to analyze forced vibrations of a piezoelectric-piezomagnetic ceramic nanoplate by a new refined shear deformation plate theory in conjunction with higher-order nonlocal strain gradient theory. As both stress nonlocality and strain gradient size-dependent effects are taken into account using the higher-order nonlocal strain gradient theory, the governing equations of the composite nanoplate are formulated....
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Structure and electric transport properties of Ca-doped bulk PrBa2Cu3O7−δ
PublicationThe crystal structure and electric transport properties of Pr1-xCaxBa2Cu3O7- delta (x= 0.0, 0.1, 0.2, 0.5) bulk ceramic samples, prepared by the standard solid-state reaction in air, were examined by X-ray power diffraction, resistivity measurements and room temperature thermoelectric power determination. Ca atoms introduce additional holes to the system as well as structural defects. The orthorhombic-to-tetragonal structural...
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Effect of MAO coatings on cavitation erosion and tribological properties of 5056 and 7075 aluminum alloys
PublicationTwo ceramic coatings have been applied on 5056 and 7075 aluminum alloy by microarc oxidation (MAO) technology. The mass losses, surface morphologies and the phase constituents of the MAO coatings before and after cavitation tests were examined by means of digital scales, scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. In order to assess the impact of the mechanical properties of the surface layer on...
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Electrical properties of nanostructures in lead-silicate glasses and nanocomposites doped with iron oxide
Open Research DataElectrical properties of iron oxide nanostructures observed in silicate glasses and glass-ceramics were studied. Two different sets of glass samples were prepared. The first group of samples has the composition of (50 − 0.5x)SiO2–(50 − 0.5x)PbO– xFe2O3, where x = 15, 20 and 25 (in mol%). Composition of the second group was 50SiO2–(50−x)PbO–xFe2O3, where...
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Magnetic properties of of lead-silicate glasses and nanocomposites doped with iron oxide
Open Research DataMagnetic properties of iron-doped glasses and glass-ceramics were studied. Two different sets of glass samples were prepared. The first group of samples has the composition of (50 − 0.5x)SiO2–(50 − 0.5x)PbO– xFe2O3, where x = 15 and 20 (in mol%). Composition of the second group was 50SiO2–(50−x)PbO–xFe2O3, where x=15, 20 and 25 (in mol%). All sampleswere...
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Marcin Wekwejt dr inż.
PeopleMarcin Wekwejt holds a bachelor’s degree in Biomedical Engineering (2016; J. and J. Śniadecki Bydgoszcz University of Technology & L. Rydygier Collegium Medicum), a master’s degree in Mechanical-Medical Engineering (2018; Gdańsk University of Technology & Gdańsk Medical University), and a PhD in Materials Engineering (2021; Gdańsk University of Technology). He was awarded the title of Doctor of Engineering and Technical...
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Sliding friction of alumina (Al2O3) with friction induced vibrations
Open Research DataTest files containing data on experiments in self mated sliding contact of alumina Al2O3 lubricated with either water or paraffin oil. Tests run in variable load/velocity conditions and with different dynamic settings of the test rig (PT-3 tribometer). The aim of the research was to attempt in finding correlations between the dynamic characteristics...
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Analiza elementarna i potencjał energetyczny osadów ściekowych z oczyszczalni ścieków w Gdyni Dębogórzu oraz Lęborku
PublicationPrzedmiotem pracy jest przedstawienie wyników analizy elementarnej osadów ściekowych z oczyszczalni ścieków w Gdyni Dębogórzu i Lęborku. W artykule przedstawiono również wyniki pomiaru ciepła spalania oraz obliczone wartości opałowe wg normy PN-93/Z-15008, uwzględniające zawartość wody, osadów na różnych etapach przeróbki w obu obiektach. Wyniki przedstawione w treści uzyskano na podstawie próbek pobranych w okresie od sierpnia...
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Influence of yttria surface modification on high temperature corrosion of porous Ni22Cr alloy
PublicationProtective coatings for porous alloys for high temperature use are relatively new materials. Their main drawback is high temperature corrosion. In this work protective coatings based the on Y-precursor infiltrated into the sintered Ni22Cr alloys are studied at 700°C. Effects of the amount of the protective phase on the resulting corrosion properties are evaluated in air and humidified hydrogen. Weight gain of the samples, their...
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Effects of La Content on the Densification, Microstructure, and Conductivity of Doped La10−x Ge6 O26±δ Electrolytes
PublicationIn this study, the influence of La content on the characteristics of Nb-, Mo-, and W-doped LaxGe6O26±δ electrolytes was investigated through sintering study, X-ray diffraction, scanning electron microscopy, and conductivity measurement. The densification of LaxGe5.5Nb0.5O26±δ and LaxGe5.5W0.5O26±δ was retarded as the x reached 9.75, while that of LaxGe5.5Mo0.5O26±δ improved with increasing La content. The average grain size slightly...
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Theoretical and experimental assessment of parameters for the non-linear viscoelastic model of structural pounding
PublicationZjawisko zderzeń pomiędzy sąsiednimi konstrukcjami budowlanymi podczas trzęsień ziemi jest w ostatnim czasie intensywnie badane z wykorzystaniem różnych modeli numerycznych siły zderzenia w czasie kontaktu. Wyniki badań eksperymentalnych pokazują, iż nieliniowy model lepko-sprężysty jest najdokładniejszy wśród modeli stosowanych do analizy. Model ten zdefiniowany jest poprzez dwa parametry: liczbę tłumienia zderzenia oraz parametr...
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Anna Lisowska-Oleksiak prof. dr hab.
PeopleAnna Lisowska-Oleksiak, born in 1952, has been working at GUT since 1977. Currently is employed at the Faculty of Chemistry as a full professor. She was employed as a research assistant at the University of St Andrews in the group of C. A. Vincent and P.G. Bruce (1991-1994). She completed a two-month research internship in CEA Grenoble (2011). Anna Lisowska-Oleksiak obtained her MSc in chemistry at Nicolaus Copernicus University...
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Method of Monitoring of the Grinding Process with Lapping Kinematics Using Audible Sound Analysis
PublicationUtilising microphones as audible sound sensors for monitoring a single-side grinding process with lapping kinematics is presented in the paper. The audible sound generated during grinding depended on the cutting properties of electroplated tools with D107 diamond grains and different thicknesses of the nickel bond. The tool wear affected the obtained technological effects such as material removal rate and the surface roughness...
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Nanotubular oxide layers and hydroxyapatite coatings on ‘Ti–13Zr–13Nb’ alloy
PublicationThe presented research was aimed to determine the mechanical properties of the nanotubular oxide layer covered with hydroxyapatite coating. The Ti–13Zr–13Nb alloy was oxidised in 1M phosphoric acid with an addition of 0?5% HF for HF solution at 20 V voltage. The electrochemically assisted deposition of hydroxyapatite was performed at cyclic polarisation in NH4H2PO4 and CaCl2 solution at 80uC. The mechanical properties were determined...
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Thermochemical Conversion of Biomass and Municipal Waste into Useful Energy Using Advanced HiTAG/HiTSG Technology
PublicationAn advanced thermal conversion system involving high-temperature gasification of biomass and municipal waste into biofuel, syngas or hydrogen-rich gas is presented in this paper. The decomposition of solid biomass and wastes by gasification is carried out experimentally with a modern and innovative regenerator and updraft continuous gasifier, among others. A ceramic high-cycle regenerator provides extra energy for the thermal conversion...
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Sposób otrzymywania mieszaniny tlenków metali przejściowych o postaci aerożelu
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Analiza elementarna i potencjał energetyczny osadów ściekowych z oczyszczalni ścieków w Gdańsku, Lęborku oraz Swarzewie
PublicationPrzedmiotem pracy jest przedstawienie wyników analizy elementarnej osadów ściekowych z wybranych oczyszczalni ścieków w woj. pomorskim. W artykule przedstawiono również wyniki pomiaru ciepła spalania oraz obliczone wartości opałowe wg normy PN-93/Z-15008, uwzględniające zawartość wody, osadów na różnych etapach przeróbki w obu obiektach. Wyniki przedstawione w treści uzyskano na podstawie próbek pobranych w okresie od sierpnia...
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Mieszane przewodnictwo polaronowo-jonowe szkieł tlenkowych
PublicationPrzeanalizowano klasyczny dla szkieł tlenkowych, zawierających jony metali przejściowych, polaronowy mechanizmu transportu ładunku. Uwzględniono wielofononowe oddziaływania polaronu z fononami akustycznymi i optycznymi. Otrzymane zależności wykorzystano do analizy własnych danych doświadczalnych.Zbadano mieszane przewodnictwo polaronowo-jonowe w kilku rodzinach szkieł tlenkowych zawierających tlenki metali przejściowych. Zaobserwowano...
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Kościół grodowy w Gdańsku. Studium z pogranicza historii i architektury
PublicationW części pierwszej artykułu przedstawiony został zarys dziejów kościoła grodowego, noszącego wezwanie mariackie. Powstał on ok. poł. XII w. i istniał aż do końca lat dwudziestych XIV w. W XIII w. lokowana była przy nim grupa kanonicka pełniąca pełniąca funkcje kancelaryjne przy księciu Świętopełku II i Warcisławie II. Kościół przetrwał zniszczenie Gdańska przez Krzyżaków i był przez nich użytkowany aż do rozpoczęcia budowy zamku...
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Badania nad docieraniem płaskich elementów ceramicznych z wymuszonym dawkowaniem zawiesiny ściernej
PublicationW pracy przedstawiono zagadnienia dotyczące obróbki wykończeniowej płaskich uszczelnień ceramicznych. Wymagania obróbkowe stawiane tego typu elementom sprawiają, że konieczne jest zastosowanie docierania w procesie technologicznym. Tego typu bardzo dokładna obróbka ścierna powierzchni płaskich wymaga użycia odpowiedniej zawiesiny lub pasty ściernej. Na wynik obróbki ma wpływ wiele czynników związanych z metalową tarczą docierającą,...
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Hebb–Wagner polarization method for determining the oxygen ion conductivity in barium cerate-zirconate
PublicationIn this work, the partial conductivity of oxygen ions in BaCe0.6Zr0.2Y0.2O3 was studied at different temperatures and water partial pressures. For this purpose, a modified DC Hebb–Wagner polarization method with an electrode blocking for protons and electrons was used. A new type of measuring cell as well as a suitable calculation model were proposed for the determination of partial oxygen ionic conductivity in materials with three...
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MSµSOFC Porous metal supported micro-scale solid oxide fuel cells: fundamentals, fabrication and testing
ProjectsProject realized in Department of Functional Materials Engineering according to UMO-2020/38/L/ST8/00513 agreement from 2021-07-06
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Prediction of coking dynamics for wet coal charge
PublicationA one-dimensional transient mathematical model describing thermal and flow phenomena during coal coking in an oven chamber was studied in the paper. It also accounts for heat conduction in the ceramic oven wall when assuming a constant temperature at the heating channel side. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. The histories of temperature, gas evolution and internal...
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High-temperature properties of titanium-substituted yttrium niobate
Publicationhe defect fluorite titanium-doped yttrium niobate samples Y3Nb1−xTixO7−δ have been synthesized and investigated by the means of high-temperature X-ray diffraction, dilatometry, and thermogravimetry. Thermal expansion coefficients (TECs) as well as chemical expansion coefficients for material with 5, 10, and 15 mol% of titanium were determined. All investigated samples exhibit chemical contraction caused by Ti doping. The values...
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Wear in siding friction tests. Ring-on-ring contact. Sintered alumina ceramics (98%). Paraffin oil lubrication. Specim. sets #20-#21, #22-#23, #24-#25, #26-#27, #28-#29,#30 - #31. Run time: 0-4h. High frequency burst recording.
Open Research DataWear in sliding friction tests in ring-on-ring contact. Sintered alumina ceramics (98%) in self-mated contact. Lubrication: paraffin oil. Sliding velocity: 0.2 m/s. Mean contact stress: 10 MPa. Test rig: PT-3 Tribometer. High frequency burst recording.Running time: 0 - 4h.Specimen sets:Specim. sets (# [upper, rotating] - #[lower, non-rotating]):#20-#21,...
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Przebieg wpracowywania kwarcowych złóż filtracyjnych przeznaczonych do usuwania manganu i azotu amonowego z wód podziemnych.The course of ripenining of quartz sand filter beds used for manganese and ammonium nitrogen removal from the groundwaters.
PublicationPrzeprowadzone badania wykazały, ze czas wpracowywania się kwarcowego złoża filtracyjnego w procesie odmanganiania i nitryfikacji trwał od 7 do 8 tygodni (złoże wpracowywało się jednocześnie w obu procesach) Wpracowanie uzyskano filtrując napowietrzoną wodę podziemną o stosunkowo wysokich stężeniach manganu (0,6 - 1,1 mg/l) i azotu amonowego (0,4 - 1,4 mgN/l) i niewielkich stężeniach żelaza (poniżej 0,5 mg/l). Po wpracowaniu...
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Badanie parametrów wewnętrznego reformingu biogazu w tlenkowych ogniwach paliwowych z anodowymi warstwami katalitycznymi Ce0,9Pr0,1O2-δ i Ce0,9Sm0,1O2-δ
PublicationOgniwa paliwowe są obiecującą alternatywą dla energetyki opartej na paliwach kopalnych. Tlenkowe ogniwo paliwowe to urządzenie elektrochemiczne, które pozwala na bezpośrednie przetwarzanie energii chemicznej paliwa na energię stałego prądu elektrycznego. Standardowo wykorzystywanym paliwem jest wodór, który podczas utleniania nie wytwarza zanieczyszczeń, a produktami reakcji są woda i ciepło. Jednakże składowanie i transport czystego...
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Electrical and noise responses of the ink-printed WS2-based gas sensor for sensing mixtures of NO2 and NH3 under UV light (275 nm)
Open Research DataThe data set consists of results collected for the resistive gas sensor composed of 2D flakes of tungsten disulfide (WS2) printed on the ceramic substrate: 1) time-resolved DC resistance measurements and 2) low-frequency noise measurements realized in the dark and under UV light assistance (275 nm) for selected gas atmospheres (NO2 and NH3 as target...
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Impact of strontium non-stoichiometry of SrxTi0.3Fe0.7O3-δ on structural, electrical, and electrochemical properties for potential oxygen electrode of intermediate temperature solid oxide cells
PublicationThis work presents the results of a comprehensive study on the impact of the A-site non-stoichiometry of SrxTi0.3Fe0.7O3-δ (x = 0.90, 0.95, 1.00, 1.05) ceramics on their physicochemical properties. The materials were fabricated by the conventional solid-state reaction method and their structure was determined by X-ray diffractometry, X-ray photoelectron spectroscopy and electron microscopy. Their sintering and thermal expansion...
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A review: Fabrication of porous polyurethane scaffolds
PublicationThe aim of tissue engineering is the fabrication of three-dimensional scaffolds that can be used for the reconstruction and regeneration of damaged or deformed tissues and organs. A wide variety of techniques have been developed to create either fibrous or porous scaffolds from polymers, metals, composite materials and ceramics. However, the most promising materials are biodegradable polymers due to their comprehensive mechanical...
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Educational and cognitive aspects of adaptation of nonuse spaces in monumental sacral objects.
PublicationThe area of attics and towers in historic churches in Europe are yet quite inaccessible places for visitors, shrouded in the atmosphere of mysticism, hiding many secrets. Introduction of the new public function into the non-used zones of the monumental sacral objects has many aspects including educational and cognitive ones which are discussed in the following article. The article indicates items that can be found in the zone above...
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Jagoda Budnik
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Influence of silver nanoparticles addition on antibacterial properties of PEO coatings formed on magnesium
PublicationMagnesium is a biodegradable material and thus could be a choice for bone fixation devices and implants with a specific purpose. This study aims to enhance the anti-corrosive, biocompatible, and antibacterial properties on magnesium-based materials through ceramic coatings formation. To achieve this the silicate-based electrolyte was used to create of Plasma Electrolytic Oxidation (PEO) coatings. During investigation the bioactive...
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Electrodeposited Biocoatings, Their Properties and Fabrication Technologies: A Review
PublicationCoatings deposited under an electric field are applied for the surface modification of biomaterials. This review is aimed to characterize the state-of-art in this area with an emphasis on the advantages and disadvantages of used methods, process determinants, and properties of coatings. Over 170 articles, published mainly during the last ten years, were chosen, and reviewed as the most representative. The most recent developments...
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Reducing common mode voltage and bearing currents in quasi - resonant DC - link inverter
PublicationIn the paper, a concept of separation of an inverter-fed induction motor drive from its mains supply by two transistor switches inserted in the dc-link circuit is reexamined based on the proposed parallel quasi-resonant dc-link inverter (PQRDCLI). The objective of the paper is to show an advantage of the proposed topology in limiting high frequency common mode voltage and bearing currents. In the laboratory setup, an induction...
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Fabrication and electrical characterization of thin film multicomponent oxides
ProjectsProject realized in Laboratorium Materiałów Funkcjonalnych ETI according to DEC-2018/02/X/ST5/01878 agreement from 2018-12-05
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Structure and transport properties of triple-conducting BaxSr1−xTi1−yFeyO3−δ oxides
PublicationIn this work, BaxSr1−xTi1−yFeyO3−δ perovskite-based mixed conducting ceramics (for x = 0, 0.2, 0.5 and y = 0.1, 0.8) were synthesized and studied. The structural analysis based on the X-ray diffraction results showed significant changes in the unit cell volume and Fe(Ti)–O distance as a function of Ba content. The morphology of the synthesized samples studied by means of scanning electron microscopy has shown different microstructures...
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PoRaCoat Innovative stent coating with polyphenol-rapamycin complex with improved drug-eluting properties to target in-stent-restenosis
ProjectsProject realized in Laboratorium Materiałów Funkcjonalnych ETI
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Arkadiusz Dawczak
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Właściwości elektryczne i magnetyczne szkła Fe2O3 – SiO2 – PbO
PublicationSzkło Fe2O3–SiO2–PbO wydaje się być obiecującym materiałem do zastosowań w urządzeniach elektrycznych takich jak rdzenie cewek, czujniki pola magnetycznego oraz mikrotransformatory. Jest to spowodowane korzystnymi właściwościami takimi jak stosunkowo wysoka rezystywność oraz w miarę duża przenikalność magnetyczna. Pierwsza wymieniona cecha skutkuje brakiem strat energii na prądy wirowe. Natomiast druga cecha oznacza potencjalną...
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Technologie Materiałów Budowlanych
e-Learning CoursesWykład: Klasyfikacja materiałów budowlanych. Naturalne materiały kamienne. Ceramika budowlana. Mineralne spoiwa budowlane. Zaczyny i zaprawy budowlane. Wyroby z zaczynów i zapraw budowlanych. Beton zwykły, wysokowartościowy i specjalny. Betony lekkie. Drewno i materiały drewnopochodne. Szkło budowlane. Tworzywa sztuczne i malarskie materiały budowlane. Lepiszcza bitumiczne i wyroby z nich. Metale i wyroby z metali. Materiały i...
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The Effect of Sodium Tetrafluoroborate on the Properties of Conversion Coatings Formed on the AZ91D Magnesium Alloy by Plasma Electrolytic Oxidation
PublicationMagnesium and its alloys are widely used in many areas because of their light weight, excellent dimensional stability, and high strength-to-weight ratio. However, the material exhibits poor wear and corrosion resistance, which limits its use. Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on Mg and their alloys. The influence of the additions of sodium tetrafluoroborate...
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Design of an Autonomous IoT Node Powered by a Perovskite-Based Wave Energy Converter
PublicationThis paper presents the results of experimental research focused on wave energy harvesting and its conversion to power Internet of Things (IoT) devices. The harvesting and conversion process was performed using a wave energy converter (WEC) consisting of a lead zirconate titanate piezoelectric ceramic perovskite material and a prototype power electronic circuit. The designed WEC was considered as a power supply for an end node...
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Composite Materials Based on Silicon Oxycarbide as Anodes for Lithium-Ion Batteries
PublicationIn this work, the properties of binary SiOC/graphite and SiOC/tin, as well as ternary SiOC/graphite/tin obtained from various preceramic precursors are described. During the first step, the materials were synthesized using various techniques such as sol-gel and hydrosilylation. To prevent sedimentation and agglomeration of graphite particles during the gelation stage without using surfactants and thickeners, a new gelation technique...
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Potentiometric Oxygen Sensor with Solid State Reference Electrode
PublicationThe concentration or the partial pressure of oxygen in an environment can be determined using different measuring principles. For high temperature measurements of oxygen, ceramic-based sensors are the most practical. They are simple in construction, exploration and maintenance. A typical oxygen potentiometric sensor consists of an oxygen ion conducting solid electrolyte and two electrodes deposited...
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Improvement of the Chimney Effect in Stack Ventilation
PublicationThe article is focused on the airflow in a ventilation system in a building. The work examines the methods which enhance the chimney effect. In this paper, three cases with different chimneys were analyzed for the full-scale experiment. These cases were characterized by different geometrical and material parameters, leading to differences in the intensity of the ventilation airflow. The common denominator of the cases was the room...
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New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties
PublicationIn this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite...
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Structure and hyperfine interactions in Bi1−xNdxFeO3 solid solutions prepared by solid-state sintering
PublicationThe series of polycrystalline ceramic powders, Bi1xNdxFeO3 (x = 0.11) was successfully synthesized by mixed oxide method followed by pressureless sintering. X-ray diffraction and Mössbauer spectroscopy were used as complementary methods to study structure and hyperfine interactions of the samples. It was found that with an increase of Nd content, within the range of x = 0.20.3 a structural phase transition from rhombohedral to...
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Investigation of the thermal conductivity of λ gypsum using the hot wire method
Open Research DataAn experimental study was conducted to determine the thermal conductivity coefficient λ using the ‘hot wire’ method for a building material. Gypsum specimens measuring 400 x 60 x 50 mm were made for the experiment. Along the long axis of the model, an insulated resistance wire with a diameter of 0.2 mm was poured into the gypsum slurry in the centre...