Search
Filters
total: 525
filtered: 213
Search results for: PARASITIC CAPACITANCES
-
Modeling the effect of parasitic capacitances on the dead-time distortion in multilevel NPC inverters
PublicationA simple model is derived and verified for evaluating the effect of parasitic capacitances on the dead-time related voltage distortion in multilevel NPC voltage source inverters. The model permits well-defined and precise compensation of dead-time distortion, exhibiting meaningful improvement on compensation methods neglecting the effects of parasitic capacitances. A simple formula is given for evaluating the capacitances as serial/parallel...
-
Reduction of parasitic pitch variations in archival musical recordings
PublicationA new method for reducing parasitic pitch variations in archival audio recordings is presented. The method is intended for analyzing movie soundtracks recorded in optical films. It utilizes image processing for calculating and reducing effects of tape shrinkage being one of the main reasons for parasitic pitch variations in audio accompanying moving images. As long as the film tape characteristics are known the new method can be...
-
Voltage Dependence of Supercapacitor Capacitance
PublicationElectronic Double-Layer Capacitors (EDLC), called Supercapacitors (SC), are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We...
-
Localization in wireless sensor networks using switched parasitic antennas
PublicationA switched parasitic monopole antenna for 2.4 GHz ISM applications is design and investigated in this paper. One of the most promising applications for such switched-beam antennas is localization in wireless sensor networks (WSN). It is demonstrated that the use of this antenna improves accuracy of localization algorithms and allows for reduction of the number of reference nodes in localization system.
-
Enhancing Performance of Switched Parasitic Antenna for Localization in Wireless Sensor Networks
PublicationThis paper presents an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna with enhanced performance of estimating the incoming signal direction. Designed antenna is dedicated for 2.4 GHz ISM applications with emphasis on Wireless Sensor Networks (WSN). The limitations of the existing design approach are illustrated, as well as perspectives and challenges of the proposed solution in relation to the localization in...
-
Improved jamming resistance using electronically steerable parasitic antenna radiator
PublicationThis paper presents an idea of using an Electronically Steerable Parasitic Antenna Radiator (ESPAR) for jamming suppression in IEEE 802.11b networks. Jamming (intentional interference) attacks are known to be effective and easy to perform, which may impose connectivity problems in applications concerning Internet of Things (IoT). In our paper, theoretical considerations are presented and the results of experiments performed in...
-
Enhanced switched parasitic antenna with switched active monopoles for indoor positioning systems
PublicationThis paper presents the concept of enhanced reduced-size steerable antenna array with two rows of switched active and passive elements. Designed array is similar to ESPAR antenna but it has a set of switched monopoles instead of central one. It is intended for 2.4 GHz ISM applications with emphasis on indoor positioning systems (IPS). Proposed antenna provides improved radiation parameters and reduced dimensions in comparison to...
-
Phytochemical and Bioactive Properties of Phelypaea Tournefortii – Effect of Parasitic Lifestyle and Environmental Factors
Publication -
Adaptive estimation of the transformer stray capacitances for DC–DC converter modelling
PublicationNew low cost and accurate estimation method of transformer stray capacitances for wide band DC–DC converter modelling and design is proposed. The Wiener filter (WF) method is applied to estimate the transformer impedance – referred to the selected transformer winding configurations. Laboratory tests are used to adapt the filter, that is to find optimal impedance which minimises mean square error between measured, noise perturbed...
-
Comment on "On accurate capacitance characterization of organic photovoltaic cells"
PublicationIn the 100th volume of Applied Physics Letters Carr and Chaudhary have presented a work on capacitance characterization of organic photovoltaic cells. The work concerns small signal measurements of various organic photovoltaic structures. The authors however limit their considerations to one part of small signal response, namely to capacitance measured either in parallel mode or in series mode. This attitude generally does not...
-
Bbulk solids flow in silos by electrical capacitance tomography
PublicationW artykule przedstawiono wyniki doświadczeń w silosach z zastosowaniem elektrycznej tomografii pojemnościowej do pomiaru zmian wskaźnika porowatości.
-
Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
-
Influence of external walls' thermal capacitance on indoor thermal comfort
PublicationThe doctoral thesis presents the results of numerical investigations on the influence of walls’ thermal capacitance on indoor thermal comfort. A proper set of thermal parameters of a building structure can considerably limit the heating / cooling demand, and passively increase the indoor thermal comfort. However the effect of building thermal capacitance on indoor conditions is complex and not always beneficial. Among a great number...
-
Electrical capacitance tomography for studying the flow of friable materials in silos.
PublicationArtykuł opisuje możliwość aplikacji tomografii do pomiarów przepływu materiałów sypkich w silosach
-
Anisakid Parasites of Fishes Caught on the African Shelf
Publication -
Grzybolubka lepka Asterophora parasitica(Pers.: FR.) Singer w Lasach Oliwskich (Trójmiejski Park Krajobrazowy) = Asterophora parasitica (Pers.:Fr) Singer in Oliwskie Forests (Trójmiejski Landscape Park)
PublicationW pracy przedstawiono stanowisko grzybolubki lepkiej zlokalizowane w Lasach Oliwskich oraz zamieszczono opis gatunku.
-
Application of Electrical Capacitance Tomography for bulk solids flow analysis in silos
PublicationW artykule przedstawiono wyniki aplikacji metody ECT w analizie przepływów materiałów sypkich, zarówno bezkohezyjnych, jak również kohezyjnych. Omówiono podstawy techniczne metody ECT, przeprowadzono dyskusje parametrów zmiennych (zagęszczenie początkowe, szorstkość ścian).
-
The influence of sampling parameters on accuracy of capacitance measurement in the method based on DSP.
PublicationW artykule przedstawiono metodę pomiaru parametrów impedancyjnych bazującą na próbkowaniu sygnałów pomiarowych i DSP. Przeanalizowano wpływ głównych źródeł niepewności i błędów na dokładność pomiaru pojemności. Zawarto analizę dla następujących parametrów: niesynchroniczne próbkowanie sygnałów pomiarowych (napięciowego i prądowego), rozdzielczość przetwornika a/c i ilość zbieranych próbek. Załączono wyniki symulacji.
-
Analysis of coplanar-type printed lines including parasitic effects of bonding wires between ground conductors
PublicationW pracy przedstwiono wyniki analizy propagacji sygnałów prostokątnych w strukturach sprzężonych falowodów koplanarnych z uwzględnieniem nieidealności połączeń pomiędzy przewodnikami masy. Wyniki analiz numerycznych dla wybranych struktur linii sprzężonych zweryfikowano pozytywnie w oparciu o rezultaty badań eksperymentalnych prowadzonych technikami czasowymi (TDR/TDT).
-
Ultra-Wideband Vivaldi Antenna with an Integrated Noise-Rejecting Parasitic Notch Filter for Online Partial Discharge Detection
PublicationPower transformers and gas-insulated switchgear (GIS) play crucial roles in electrical power grids. However, they may suffer from degradation of insulation material due to wear and tear, leading to their imminent failure. Partial discharges (PDs) are an initial sign of insulation materials degradation which emit signals spanning various physical domains, including electromagnetic. PDs are temporally narrow, high-frequency, stochastic...
-
EMI mitigation of GaN power inverter leg by local shielding techniques
PublicationThis paper presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common mode (CM) current noise at converter’s DC input. The research study is conducted for 650V Enhancement mode Gallium Nitride (GaN) power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce...
-
Screening of protozoan and microsporidian parasites in feces of great cormorant (Phalacrocorax carbo)
Publication -
Direction of Arrival Estimation Based on Received Signal Strength Using Two-Row Electronically Steerable Parasitic Array Radiator Antenna
PublicationIn this paper, we present a novel approach to direction-of-arrival (DoA) estimation using two-row electronically steerable parasitic array radiator (ESPAR) antenna which has 12 passive elements and allows for elevation and azimuth beam switching using a simple microcontroller, relying solely on received signal strength (RSS) values measured at the antenna output port. To this end, we thoroughly investigate all 18 available 3D antenna...
-
Enhanced capacitance of composite TiO2 nanotube / boron-doped diamond electrodes studied by impedance spectroscopy
PublicationWe report on the novel composite nanostructures based on boron-doped diamond thin film grown on top of TiO2 nanotubes. The nanostructures made of BDD-modified titania nanotubes showed an increase in activity and performance when used as electrodes in electrochemical environments. The BDD thin films (~200-500 nm) were deposited using microwave plasma assisted chemical vapor deposition (MW PA CVD) onto anodically fabricated TiO2...
-
Enhanced capacitance of composite TiO2 nanotube/boron-doped diamond electrodes studied by impedance spectroscopy
Publication -
Understanding the capacitance of thin composite films based on conducting polymer and carbon nanostructures in aqueous electrolytes
PublicationIn this work electrochemical performance of thin composite films consisted of poly(3,4-ethylenedioxythiophene) (PEDOT), graphene oxide (GOx) and oxidized multiwalled carbon nanotubes (oxMWCNTs) is investigated in various sulphates (Li2SO4, Na2SO4, K2SO4, MgSO4) and acidic (H2SO4) electrolytes. Capacitance values, rate capability and cycling stability achieved for the composite layers are correlated with the electrolytes’ properties...
-
Capacitance Enhancement by Incorporation of Functionalised Carbon Nanotubes into Poly(3,4-Ethylenedioxythiophene)/Graphene Oxide Composites
PublicationThis paper reports on the role of oxidised carbon nanotubes (oxMWCNTs) present in poly-3,4-ethylenedioxytiophene (PEDOT)/graphene oxide (GOx) composite. The final ternary composites (pEDOT/GOx/oxMWCNTs) are synthesised by an electrodeposition process from the suspension-containing monomer, oxidised carbon nanotubes and graphene oxide. Dissociated functional groups on the surface of graphene oxide play a role of counter-ions for the...
-
Application of electrical capacitance tomography (ECT) to measurement of sand concentration changes during silo flow
PublicationW artykule przedstawiono wyniki doświadczeń pomiaru zmian koncentracji materiału granulowanego podczas przepływu silosowego. Zmiany zostały pomierzone przy pomocy tomografu. Doświadczenia wykonano w silosie cylindrycznym dla 2 różnych szorstkości ścian.
-
Phytochemical parasite-host relations and interactions: A Cistanche armena case study
Publication -
Can mutations in the gene encoding transcription factor EKLF (Erythroid Krüppel-Like Factor) protect us against infectious and parasitic diseases?
Publication -
On small signal capacitance spectra of organic diode formed by ITO-palladium phthalocyanine-Al sandwich system
PublicationPraca poświęcona jest widmom małosygnalowej pojemności w zakresie 25 Hz-1 MHz i charakterystyce prądowo-napięciowej planarnego układu utworzonego przez ITO/ftalocyanina palladu/Al.
-
Parasites of the digestive tract of sheep and goats from organic farms in Western Pomerania, Poland
PublicationThe aim of the study was to determine the prevalence and intensity of parasite infection of the digestive tract in sheep and goats from the West Pomerania region following anti-parasite treatment. Feces were freely collected from sheep and goats kept on organic farms and subjected to analysis by the Willis-Schlaf and McMaster’s flotation methods. The mean extensity of infection by gastrointestinal parasites...
-
Small signal spectra of complex capacitance obtained on organic heterojunction formed from copper phthalocyanine and perylene dye
PublicationPraca przedstawia małosygnałowe widma zespolonej pojemności otrzymane na strukturze z heterozłączem organicznym CuPc/Py-PTC w zakresie 25Hz-1MHz.
-
Electrodes consisting of PEDOT modified by Prussian Blue analogues deposited onto titania nanotubes – Their highly improved capacitance
PublicationIn this work we present the outstanding energy storage of prepared inorganic-organic heterojunction where hydrogenated ordered titania nanotubes (H-TiO2NT) were modified by the hybrid made of poly(3,4-ethylenedioxythiophene) (pEDOT) and iron hexacyanoferrate centres (Fehcf, Prussian Blue). The material TiO2NT/pEDOT:Fechf was obtained electrochemically by means of: anodization, hydrogenation and finally, electropolymerization of...
-
A non-quasi-static-signal MOSFET model for radio and microware frequencies including spreading gate resistances and capacitaces.
PublicationZaprezentowano nowy, spójny fizycznie nie-quasi-statyczny model małosygnałowy tranzystora MOS słuszny od 0 Hz aż do częstotliwości mikrofalowych. Scharakteryzowano właściwości nowego czterokońcówkowego modelu. Model został zweryfikowany eksperymentalnie aż do częstotliwości 27 GHz.
-
Nowe stanowisko podgrzybka pasożytniczego Xerocomus parasiticus w Trójmiejskim Parku Krajobrazowym (Pomorze Gdańskie).
PublicationOpisano 67 stanowisko w kraju i drugie w Trójmiejskim Parku Krajobrazowym rzadkiego przedstawiciela grzybów wielkoowocnikowych (macromycetes) - podgrzybka pasożytniczego Xerocomus parasiticus, pasożytującego na tęgoskórze pospolitym scleroderma citrinum. Przedstawiono budowę morfologiczną owocnika podgrzybka oraz jego ekologię, a także ekologię gospodarza - tęgoskóra pospolitego. Opisano okoliczne zbiorowisko leśne, wymieniono...
-
Modeling of Common Mode Currents Induced by Motor Cable in Converter Fed AC Motor Drives
PublicationInvestigation of conducted EMI generation in AC motor fed by pulse width modulated frequency converters requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. Motor voltage transients and related common mode currents are significantly correlated with resonance effects occurring in load circuits. An analysis of frequency converter load impedance-frequency characteristics...
-
A Comparison of the Prevalence of Gastrointestinal Parasites in Wild Boar (Sus scrofa L.) Foraging in Urban and Suburban Areas
Publication -
The phenomenon of increasing capacitance induced by 1T/2H-MoS2 surface modification with Pt particles – Influence on composition and energy storage mechanism
PublicationIn this paper, several approaches to the synthesis of molybdenum-based electrode materials for supercapacitors are presented, including anodization, hydrothermal process and annealing. For the material prepared via anodization of a molybdenum plate, followed by a hydrothermal process in thiourea aqueous solution, a thorough study of the Pt-surface modification through repetitive cycling in 1 M sulfuric acid with Pt acting as a...
-
Investigations of porosity changes during granular silo flow using Electrical Capacitance Tomography (ECT) and Particle Image Velocimetry (PIV)
PublicationArtykuł omawia pomiary zmian porowatości podczas przepływu silosowego materiału granulowanego. Zastosowano 2 techniki: tomografie i optoelektroniczną DIC. Pomiary wykonano dla różnych początkowych zagęszczeń oraz szorstkości ścian.
-
Broadband Modeling of Motor Cable Impact on Common Mode Currents in VFD
PublicationExamination of conducted EMI generation and propagation in AC motor drives fed by frequency converter requires to consider parasitic capacitances in converters, motor windings and feeding cables to be taken into account. AC motor winding voltage transients and related common mode currents are significantly correlated with resonance effects occurring in converter's load circuits. Intensity levels of these phenomena depend...
-
Motor Cable Influence on the Conducted EMI Emission of the Converter Fed AC Motor Drive. - Vol. 1
PublicationInvestigation of conducted electromagnetic interference in AC motor drives fed by pulse width modulated voltage converters requires considering parasitic capacitances in converters, motor windings and feeding cables to be taken into account. Motor voltage transients and related conducted electromagnetic emission are significantly correlated with resonance effects occurring in load circuits. The levels of intensity of these phenomena...
-
Titania nanotubes modified by a pyrolyzed metal-organic framework with zero valent iron centers as a photoanode with enhanced photoelectrochemical, photocatalytical activity and high capacitance
PublicationThe paper discusses the synthesis, photoelectrochemical and electrochemical behaviour of titania nanotube arrays modified by a pyrolyzed metal-organic framework (MOF). A poly(3,4–ethylenedioxyphene) (PEDOT) matrix with an embedded inorganic network of iron hexacyanoferrate (BP) covering TiO2 nanotubes (TNT) is used as a MOF for the further sintering procedure, resulting in a novel, thin film of carbonaceous wrap supported Fe catalytic...
-
Correlated trophic and bioactive activities in the parasite-host relationship – Phelipanche purpurea vs. Achillea arabica case study
Publication -
THE EVALUATION OF EFFICACY OF VALBAZEN (PFLIZER) IN THE TREATMENT OF GASTRO-INTESTINAL TRACT PARASITE INVASIONS IN BEEF CATTLE OF WEST POMERANIA
Publication -
Soil contamination with geohelminths in children’s play areas in Szczecin, Poland
PublicationThe presence of invasive forms of parasites in the soil represents a potential threat to public health, especially for children. The aim of the study was to determine the degree of contamination with geohelminth eggs of soil samples collected from sandpits and playgrounds in the Szczecin area. The findings showed overall prevalence of soil samples contaminated with geohelminth eggs in the soil and sand...
-
Immunogenic and protective activity of recombinant chimeric Toxoplasma gondii proteins
PublicationToxoplasmosis, one of the most common parasitic invasions worldwide, may pose a great threat for individuals with weakened immune system. The parasite also causes considerable economic losses due to infection of livestock. To date there is no efficient immunoprophylaxis for humans and animals, which would provide long-lasting protection against T. gondii invasion. Chimeric proteins, containing several selected fragments of parasite...
-
Voltage Harmonics Transfer through Medium Voltage Instrument Transformers
PublicationVoltage transformers are widely used in power quality monitoring systems in medium and high voltage grids. This paper presents accuracy problems related to voltage harmonics transfer through instrument transformers. A simplified lumped-parameters wideband circuit model of the voltage transformer is proposed and verified by simulation and experimental investigations. A number of voltage transformers have been tested in the frequency...
-
Voltage Transients Transfer over Medium Voltage Instrument Transformers
PublicationThis paper presents voltage harmonic transfer accuracy problems through voltage transformers which are used in power quality monitoring systems in medium and high voltage grids. A simplified lumped parameters circuit model of the voltage transformer is proposed and verified by simulation and experimental investigations. A number voltage transformers typically used in medium voltage grid has been tested in the conducted disturbances...
-
Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...