Filtry
wszystkich: 10032
wybranych: 7866
-
Katalog
- Publikacje 7866 wyników po odfiltrowaniu
- Czasopisma 181 wyników po odfiltrowaniu
- Konferencje 12 wyników po odfiltrowaniu
- Wydawnictwa 4 wyników po odfiltrowaniu
- Osoby 189 wyników po odfiltrowaniu
- Projekty 17 wyników po odfiltrowaniu
- Laboratoria 1 wyników po odfiltrowaniu
- Zespoły Badawcze 1 wyników po odfiltrowaniu
- Aparatura Badawcza 9 wyników po odfiltrowaniu
- Kursy Online 120 wyników po odfiltrowaniu
- Wydarzenia 31 wyników po odfiltrowaniu
- Oferty 1 wyników po odfiltrowaniu
- Dane Badawcze 1600 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: MEDIUM FREQUENCY TRANSFORMER, POWER CONVERTER, DC-DC, DUAL ACTIVE BRIDGE, SOLID STATE TRANSFORMER
-
Influence of magnetic field on wear in high frequency reciprocatingsliding contacts
PublikacjaResults of experimental studies concerning the influence of permanent magnetic field on wear of dry sliding contact operating at short stroke and high frequency are presented. It was found that horizontal magnetic field with different orientations relative to the sliding direction is affecting performance of the contact. The increase in frequency of sliding reduces accumulated mass loss and lowers the surface roughness of the wear...
-
Impedance measurements of coating properties on bridge structures
PublikacjaPomiary impedancyjne pozwalają na prostą ocenę właściwości ochronnych powłok ochronnych i wykładzin. Pomiary stosuje się w celu porównania powłok, monitorowania ich właściwości i oceny mechanizmu działania. Metodyka jest z powodzeniem stosowana w pomiarach laboratoryjnych. Pomiary terenowe są bardziej skomplikowane ponieważ wymagają w pełni kontrolowanych komputerowo przyrządów, kontroli warunków pogodowych oraz wielu innych parametrów...
-
Meander anisotropic magnetoresistance bridge geomagnetic sensors
Publikacja -
Laser Scanning of a Soil-Shell Bridge Structure
Publikacja -
Chirp Rate and Instantaneous Frequency Estimation: Application to Recursive Vertical Synchrosqueezing
PublikacjaThis letter introduces new chirp rate and instantaneous frequency estimators designed for frequency-modulated signals. These estimators are first investigated from a deterministic point of view, then compared together in terms of statistical efficiency. They are also used to design new recursive versions of the vertically synchrosqueezed short-time Fourier transform, using a previously published method (D. Fourer, F. Auger, and...
-
Problems of Active Dynamic Thermography Measurement Standardization in Medicine
PublikacjaReliability of thermographic diagnostics in medicine is an important practical problem. In the field of static thermography, a great deal of effort has been made to define the conditions for thermographic measurements, which is now the golden standard for such research. In recent years, there are more and more reports on dynamic tests with external stimulation, such as Active Dynamic Thermography, Thermographic Signal Reconstruction...
-
On the production of electricity in Poland using a geothermal binary power plant - A thermodynamic overview - Part I
PublikacjaPoland has a significant potential of geothermal energy. However, the high-temperature sources that are needed to drive power plants are found in relatively few places. Therefore, the objective of this paper is to consider any location in the northern part of Poland as a possible place to build a binary power plant. A scientific research was confirmed the existence of an elevated temperature gradient in this region. The hot rocks...
-
Installation of Compensators in the Power System Transmission Grid
PublikacjaThe article discusses issues of reactive power compensation in transmission grids, with particular focus on the selection of compensator locations and basic parameters. Attention was focused on modern power electronics systems that ensure full automatic compensator adjustment to voltage or power criteria.
-
Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublikacjaThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
-
High frequency oscillations in human memory and cognition: a neurophysiological substrate of engrams?
PublikacjaDespite advances in understanding the cellular and molecular processes underlying memory and cognition, and recent successful modulation of cognitive performance in brain disorders, the neurophysiological mechanisms remain underexplored. High frequency oscillations beyond the classic electroencephalogram spectrum have emerged as a potential neural correlate of fundamental cognitive processes. High frequency oscillations are detected...
-
Testing Situation Awareness Network for the Electrical Power Infrastructure
PublikacjaThe contemporary electrical power infrastructure is exposed to new types of threats. The cause of such threats is related to the large number of new vulnerabilities and architectural weaknesses introduced by the extensive use of Information and Communication Technologies (ICT) in such complex critical systems. The power grid interconnection with the Internet exposes the grid to new types of attacks, such as Advanced Persistent...
-
Experimental Extraction of Secure Correlations from a Noisy Private State
PublikacjaWe report experimental generation of a noisy entangled four-photon state that exhibits a separation between the secure key contents and distillable entanglement, a hallmark feature of the recently established quantum theory of private states. The privacy analysis, based on the full tomographic reconstruction of the prepared state, is utilized in a proof-of-principle key generation. The inferiority of distillation-based strategies...
-
Degree of monopoly and market power vs. price flexibility in Polish economy: empirical analysis based on COICOP classification
PublikacjaResearch background: The issue of price flexibility is crucial in the economy both in the aspect of company theory and its macroeconomic consequences. In a number of publications, the sources of variable price flexibility are linked to the market power of enterprises as well as the market structure that has developed in a given branch. It is difficult to indicate empirical studies that would state clearly whether price flexibility...
-
Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
PublikacjaSodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between...
-
Pathological and physiological high-frequency oscillations in focal human epilepsy
PublikacjaHigh-frequency oscillations (HFO; gamma: 40-100 Hz, ripples: 100-200 Hz, and fast ripples: 250-500 Hz) have been widely studied in health and disease. These phenomena may serve as biomarkers for epileptic brain; however, a means of differentiating between pathological and normal physiological HFO is essential. We categorized task-induced physiological HFO during periods of HFO induced by a visual or motor task by measuring frequency,...
-
Molecular properties with dual basis set methods
Publikacja -
Dual polarization antennas for UHF RFID readers
PublikacjaThis paper presents various concepts of switching polarization in patch antenna dedicated for UHF RFID readers. Proposed designs allow for switching between linear and circular polarization. The first design does not require electronic switching as the polarization can be changed by choosing one of two available feeding terminals. Two remaining designs use PIN diode or FET SPDT switch.
-
Iterative learning approach to active noise control of highly autocorrelated signals with applications to machinery noise
PublikacjaThis paper discusses the design and application of iterative learning control (ILC) and repetitive control (RC) for high modal density systems. Typical examples of these systems are structural and acoustical systems considered in active structural acoustic control (ASAC) and active noise control (ANC) applications. The application of traditional ILC and RC design techniques, which are based on a parametric system model, on systems...
-
Influence of the internet and electronic commerce growth on polish small and medium enterprises. PODAĆ POLSKI TYTUŁ.
PublikacjaTechnological development in communication creates new possibilities for commercial activity . Each new medium was changing business processes . Internet does the same - implies rapid changes in every stage of commercial activity.The aim of this paper is to show that the Internet and Electronic Commerce are influencing the Small and Medium Enterprises (SMEs) development in Poland. For achieving this another issue had to be under...
-
Koncepcja i symulacja polowa generatora o zmiennej częstotliwości. Zastosowanie w autonomicznych systemach elektroenergetycznych = Conception and field simulations of a variable frequency generator. Application for autonomous power generation system
PublikacjaStreszczenie angielskie: This paper covers a conception and simulation results for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid, hybrid vehicle, micro-CHP). The papers has two parts: presentation of the generator conception used in modern autonomous energy generation systems, and simulation results using filed model elaborated in Flux2D software....
-
Generalized Chebyshev Bandpass Filters With Frequency-Dependent Couplings Based on Stubs
PublikacjaThis paper presents an accurate synthesis method for inline and cross-coupled generalized Chebyshev bandpass filters with frequency-dependent couplings implemented via open and short stubs. The technique involves the synthesis of a lumped-element prototy pe in the form of a coupling matrix with a frequency-dependent term and the conversion of this prototype to a distributed-element mode l composed of sections of TEM lines. This...
-
Evaluation of W-containing Sr1−Ba Fe0.75W0.25O3– (x= 0, 0.5, 1) anode materials for solid oxide fuel cells
Publikacja -
Optimal Rotating Receiver Angles Estimation for Multicoil Dynamic Wireless Power Transfer
PublikacjaThis study proposed an approach to dynamic wireless charging that uses a rotating receiver coil. Our simulation study focused on the verification of a novel way of increasing the coupling coefficient and power transfer stability by following the flux of the transmitting coils. To obtain the highest possible coupling by means of the FEM analysis, we studied the optimization of the trajectory of the angular velocity of the rotating...
-
Time-frequency analysis of acoustic signals using concentrated spectrogram
PublikacjaThe paper presents improved method of time-frequency (TF) analysis of discrete-time signals. The method involves signal's local group delay (LGD) and channelized instantaneous frequency (CIF) to purposely redistribute all Short-time Fourier transform (STFT) lines. Additionally, the energy concentration index (ECI) and some histogram-like statistics are used to evaluate readability of estimated TF distributions of the energy. Recorded...
-
Monoterpenes emissions from different samples of wood-based materials – laminated chipboards and medium-density fiberboards (MDF)
PublikacjaThe paper presents the results of studies on emission rates of monoterpenes, carried out with the use of a new type of device - Markes’ Micro-Chamber/Thermal Extractor™ (μ-CTE250). Subject of studies were different types of wood-based materials such as: laminated chipboards and medium-density fiberboards (MDF). Based on the results obtained one can conclude that the laminated chipboards may affect the indoor air quality in much...
-
Development of iron doped strontium titanates as oxygen electrode for solid oxide fuel cells
PublikacjaProducing efficient solid oxide fuel cells (SOFC) without the use of harmful elements is one of the current challenges. Increasing the safety of people and reducing production costs is possible, among others, thanks to the use of iron doped strontium titanates as porous oxygen electrodes. In this thesis, the results of research on iron doped strontium titanates as potential oxygen electrodes for SOFC are presented. The research...
-
INFLUENCE OF DREDGER POWER PLANT TYPE AND DREDGER SIZE ON OUTPUT OF POWER PLANT INSTALLED ON TRAILING SUCTION HOPPER DREDGER
PublikacjaThis paper presents results of investigations dealing with influence of parameters characterizing size of suction hopper dredger as well as type of power system on magnitude of total output of combustion engines installed in dredger power plant.
-
ANALYSIS OF THE FEATURES OF EFFECTIVE IMPLEMENTATION OF SOLAR POWER PLANTS IN LOCAL ENERGY SUPPLY SYSTEMS
PublikacjaПоказано, що відновлені джерела енергії (ВДЕ) у багатьох країнах дедалі більше домінують на ринку електроенергії, при цьому обсяги генерації електроенергії сонячними електростанціями (СЕС) останніми роками зростають рекордними темпами. Зазначено, що хоча частка ВДЕ продовжує зростати і фотоелектрична індустрія стрімко розвивається, однак галузь все ще стикається з багатьма проблемами, зокрема як продовжувати знижувати нормовану...
-
Thermodynamic Cycle Concepts for High-Efficiency Power Plans. Part A: Public Power Plants 60+
PublikacjaAn analysis was carried out for different thermodynamic cycles of power plants with air turbines. Variants with regeneration and different cogeneration systems were considered. In the paper, we propose a new modification of a gas turbine cycle with the combustion chamber at the turbine outlet. A special air by-pass system of the combustor was applied and, in this way, the efficiency of the turbine cycle was increased by a few points....
-
Effects of La0.8Sr0.2MnO3 and Ag electrodes on bismuth-oxide-based low-temperature solid electrolyte oxygen generators
PublikacjaIn this study, La0.8Sr0.2MnO3 (LSM) was used as the ceramic electrode in a (Bi1.50Y0.50)0.98Zr0.04O3+δ (BYO)-based solid electrolyte oxygen generator (SEOG) and its performance was compared with that of a previously studied high-fire Ag electrode. Among La0.6Sr0.4Co0.2Fe0.8O3, LaNi0.6Fe0.4O3, Cu1.4Mn1.6O4, and LSM materials, only LSM materials did not trigger any chemical reaction or interdiffusion with BYO at temperatures up to...
-
A Novel Versatile Decoupling Structure and Expedited Inverse-Model-Based Re-Design Procedure for Compact Single-and Dual-Band MIMO Antennas
PublikacjaMultiple-input multiple-output (MIMO) antennas are considered to be the key components of fifth generation (5G) mobile communications. One of the challenges pertinent to the design of highly integrated MIMO structures is to minimize the mutual coupling among the antenna elements. The latter arises from two sources, the coupling in the free space and the coupling currents propagating on a ground plane. In this paper, an array of...
-
Modified Inductive Multi-Coil Wireless Power Transfer Approach Based On Z-Source Network
PublikacjaThis article presents a non-conventional approach to a multi-coil wireless power transfer system based on a Z-source network. The novelty of the approach lies in the use of a Z-source as a voltage source for energy transmission through the wireless power transfer coils. The main advantage is in a reduced number of semiconductors. This paper provides the design approach, simulation and experimental study. Feasibility and possible...
-
Control of the bridge span vibration with high coefficient passive damper. Theoretical consideration and application
PublikacjaThe research was carried out due to the problem of vibration on the lively pedestrian drawbridge across the Motlawa River in the city of Gdansk. In the design stage, the main span of the footbridge showed unfavorable dynamic properties, which may create a comfort problem for pedestrians. The first vertical bending eigenfrequency was recognized as 1.64 Hz. The original design of the footbridge was equipped with a driving cylinder...
-
Rehabilitation device supporting active and passive upper limb exercises
PublikacjaThis article presents a mechatronic solution for rehabilitation devices supporting active and passive exercises in persons with motor dysfunctions of the upper limbs in the area of the elbow and shoulder joints. A planar positioner integrated with original software and a control system, served as the basis for creating the present solution. Bellman’s programming method was applied to optimize the motion trajectory of the planar...
-
Instant Messaging als neues kommunikationsinstrumentarium in eLearning systemen
PublikacjaDokonano analizy mozliwości implementacji komunikatorów w platformach zdalnego nauczania. Przedstawiono możliwe rozwiązania. Przedyskutowano wady i zalety poszczególnych rozwiazań.
-
Self-advocacy of a person with a disability in the dual role of paid worker and volunteer: Theoretical considerations and a case study
PublikacjaThe changing models of disability influence the way people with disabilities participate in social life, and how they can transform their life and environment. Such participation may take the form of work and volunteering, as well as participation in self-advocacy movements. This paper aims to explore how a woman with hearing impairment perceives her dual role as a regular worker and voluntary self-advocate within one organization...
-
Active management of equipment cooling in hoteling data centers
PublikacjaHoteling data centers are designated for housing computing and storage units of many, usually small customers, as opposed to traditional data centers supporting own computing and storage resources of a bigger company. One of the services to be provided to consumer’s equipment is cooling. Cooling in data centers is prevalently achieved by circulating air in computer room. Efficient cooling requires delivering cold air from central...
-
Removal of Pharmaceutically Active Compounds in Sequencing Batch Reactor
PublikacjaIn recent years, considerable attention was paid to the presence of organic micro-pollutants such as Active Pharmaceutical Ingredients (API) in the aquatic environment due to their negative impact on public health and aquatic ecosystems. Numerous papers have pointed out API presence as common constituents of effluents from Wastewater Treatment Plants (WWTPs). This is the result of various efficiencies of API removal by conventional...
-
Friction Stir Welding of Aluminum in the Aerospace Industry: The Current Progress and State-of-the-Art Review
PublikacjaThe use of the friction stir welding (FSW) process as a relatively new solid-state welding technology in the aerospace industry has pushed forward several developments in different related aspects of this strategic industry. In terms of the FSW process itself, due to the geometric limitations involved in the conventional FSW process, many variants have been required over time to suit the different types of geometries and structures,...
-
Cost-Efficient Surrogate Modeling of High-Frequency Structures Using Nested Kriging with Automated Adjustment of Model Domain Lateral Dimensions
PublikacjaSurrogate models are becoming popular tools of choice in mitigating issues related to the excessive cost of electromagnetic (EM)-driven design of high-frequency structures. Among available techniques, approximation modeling is by far the most popular due to its versatility. In particular, the surrogates are exclusively based on the sampled simulation data with no need to involve engineering insight or problem-specific knowledge....
-
Inverse and forward surrogate models for expedited design optimization of unequal-power-split patch couplers
PublikacjaIn the paper, a procedure for precise and expedited design optimization of unequal power split patchcouplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to thecircuit operating at the requested frequency and featuring a required power split. At the same time, thedesign process is supposed to be computationally efficient. The proposed methodology involves two typesof auxiliary models (surrogates):...
-
A Dual-Polarized 39 GHz 4x4 Microstrip Antenna Array for 5G MU-MIMO Airflight Cabin Connectivity
PublikacjaThis paper presents the design, fabrication, and experimental validation of a 39 GHz dual-polarized 4x4 microstrip antenna array. The array consists of 16 slot coupled circular microstrip patches, fed through SMPS connectors. The procedure requiring a reduced number of cables for measurement of the uniformly excited antenna array is also presented. The array exhibits 18 dBi peak gain and 2.9 GHz reflection bandwidth and is intended...
-
Controlling the europium oxidation state in diopside through flux concentration
PublikacjaThis paper explores the connection between the H3BO3 flux concentration and the co-existence of Eu2+ and Eu3+ dopants within CaMgSi2O6 crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N2), and reductive (H2/N2 mixture) environments. Additionally, some materials underwent chemical modification by partially substituting...
-
Mesoscopic impedance analysis of solid materials surface
PublikacjaSeveral techniques have been developed in order to characterize electrical properties of surfaces in micrometer/nanometer scale. Obtaining of the spatial distribution of sample resistance, capacitance or potential requires separate measurements performed in different scanning modes. On the other hand, analysis of the frequency response of investigated system enables determination of several physical quantities in single measurement...
-
Thermodynamic Cycle Concepts for High-Efficiency Power Plants. Part B: Prosumer and Distributed Power Industry
PublikacjaAn analysis was carried out for different thermodynamic cycles of power plants with air turbines. A new modification of a gas turbine cycle with the combustion chamber at the turbine outlet has been described in the paper. A special air by-pass system of the combustor was applied, and in this way, the efficiency of the turbine cycle was increased by a few points. The proposed cycle equipped with an effective heat exchanger could...
-
Stirling engines - the state of technology development and computational models
PublikacjaStirling engines represent a technologically important solution in combined heat and power systems. Their use enables the achievement of over 90 percent efficiency in the management of the primary energy source with a very high durability of the device, mainly due to the lack of contact of the working gas with external factors and a very small number of mechanical components. The use of a Stirling engine may be equally important...
-
Impact resistance of plain and twill fabric in GFRP measured by active thermography
PublikacjaThis paper discusses the impact resistance of glass-fibre reinforced polymer (GFRP) composites depending on the type of reinforcement – plain or twill weave. The values of impact energy were: 3J, 10J and 15J. Specimens featuring twill weave transferred higher force during the impact as compared with plain weave specimens. It was observed that an increase of impact energy was accompanied by an increase of the disproportion in...
-
Standing Waves in a Rectangular Resonator Containing Acoustically Active Gases
PublikacjaThe distribution of perturbations of pressure and velocity in a rectangular resonator is considered. A resonator contains a gas where thermodynamic processes take place, such as exothermic chemical reaction or excitation of vibrational degrees of a molecule’s freedom. These processes make the gas acoustically active under some conditions. We conclude that the incident and reflected compounds of a sound beam do not interact in the...
-
High frequency oscillations are associated with cognitive processing in human recognition memory
PublikacjaHigh frequency oscillations are associated with normal brain function, but also increasingly recognized as potential biomarkers of the epileptogenic brain. Their role in human cognition has been predominantly studied in classical gamma frequencies (30-100 Hz), which reflect neuronal network coordination involved in attention, learning and memory. Invasive brain recordings in animals and humans demonstrate that physiological oscillations...
-
A multistage turbine for a micro power plant
PublikacjaThis paper presents results of a design analysis of a multi-stage turbine for the cogeneration micro-power plant working in accordance with Organic Rankine Cycle (ORC). The heat power of the plant is assumed equal to 20 kW and the corresponding available electric output is estimated to be of about 3 kW. Different variants of the radial and axial-flow turbines have been considered, while the detailed results of the calculations...