Filters
total: 5024
filtered: 2907
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: F-TYPE INVERTER
-
Seven Different Lighting Conditions in Photogrammetric Studies of a 3D Urban Mock-Up
PublicationOne of the most important elements during photogrammetric studies is the appropriate lighting of the object or area under investigation. Nevertheless, the concept of “adequate lighting” is relative. Therefore, we have attempted, based on experimental proof of concept (technology readiness level—TRL3), to verify the impact of various types of lighting emitted by LED light sources for scene illumination and their direct influence...
-
Behavior of residual current devices at frequencies up to 50 kHz
PublicationThe use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied...
-
Evaluation of La 2 Ni 0.5 Cu 0.5 O 4+δ and Pr 2 Ni 0.5 Cu 0.5 O 4+δ Ruddlesden-Popper-type layered oxides as cathode materials for solid oxide fuel cells
Publication -
Isolation and restoration policies against power collapse.
PublicationPrzedstawiono zasady obrony systemów elektroenergetycznych przed tzw. blackout´em. Omówiono wielkości kryterialnych tych systemów, możliwości predykcji stanów zagrożeniowych oraz automatyki działające on line w celu zapobieżenia rozprzestrzeniania się zakłóceń i awarii w systemach elektroenergetycznych.
-
Occurrence, contamination evaluation and health risks of trace metals within soil, sediments and tailings in southern Tunisia
Publication -
Modelling of subarachnoid space width changes in apnoea resulting as a function of blood flow parameters
PublicationDuring apnoea, the pial artery is subjected to two opposite physiological processes: vasoconstriction due to elevated blood pressure and vasorelaxation driven by rising pH in the brain parenchyma. We hypothesized that the pial artery response to apnoea may vary, depending on which process dominate. Apnoea experiments were performed in a group of 19 healthy, non-smoking volunteers (9 men and 10 women). The following parameters...
-
Optimization of a three-bed adsorption chiller by genetic algorithms and neural networks
Publication -
Use of Near Infrared Transillumination/Back Scattering Sounding (NIR-T/BSS) to assess effects of elevated intracranial pressure on width of subarachnoid space and celebrovascular pulsation in animals
PublicationW pracy dokonano ocenę zmiany szerokości przestrzeni podpajęczynówkowej i tętnienia naczyń mózgowych w czasie chwilowego zwiększenia ciśnienia śródczaszkowego u królików doświadczalnych. Badania zostały przeprowadzone przy wykorzystaniu metody transiluminacji w bliskiej podczerwieni z rozpraszaniem zwrotnym NIRT-BSS.
-
Low frequency noise and reliability properties of 0.12um CMOS devices with Ta2O5 as gate dielectrics
PublicationW artykule przedstawiono wyniki badań jakości tranzystorów CMOS 0.12um z Ta2O5 użytym jako dielektryk bramki. Przedstawione są charakterystyki statyczne elementów oraz wyniki pomiarów szumów prowadzonych w celu określenia jakości warstwy dielektrycznej Ta2O5, a także wyniki badań przeciążeniowych elementów.
-
Synchronized six-step voltage generation in high-speed PMSM drive
PublicationSynchronized voltage generation has already been considered in the context of pulse width modulation (PWM). References prove that synchronized PWM substantially decreases subharmonics in inverter output voltage when operating with low switching-to-fundamental frequency ratio. This paper identifies problems of unsynchronized voltage generation in electric drives under six-step inverter operation. Guidelines for the synchronization...
-
Quadratic stochastic operators on Banach lattices
PublicationWe study the convergence of iterates of quadratic stochastic operators that are mean monotonic. They are defined on the convex set of probability measures concentrated on a weakly compact order interval S = [0, f] of a fixed Banach lattice F. We study their regularity and identify the limits of trajectories either as the “infimum” or “supremum” of the support of initial distributions.
-
RTS Noise in Optoelectronic Coupled Devices
PublicationPrzedstawiono wyniki pomiarów szumów z zakresu małuch częstotliwości transoptorów typu CNY17. Pomiary wykonano w systemie zaprojektowanym i skonstruowanym przez Autorów. Stwierdzono występowanie szumów RTS w kilku egzemplarzach badanej próby transoptorów. Przeprowadzono analizę szumów RTS, zarówno w dziedzinie czasu, jak i w dziedzinie częstotliwości. Oszacowano wartość częstotliwości, przy której występują szumy wybuchowe, na...
-
Shub’s conjecture for smooth longitudinal maps of S^m
PublicationLet f be a smooth map of the m-dimensional sphere Sm to itself, preserving the longitudinal foliation. We estimate from below the number of fixed points of the iterates of f , reduce Shub’s conjecture for longitudinal maps to a lower dimensional classical version, and prove the conjecture in case m = 2 and in a weak form for m = 3.
-
Low-frequency current noise in electrochromic devices
PublicationObserwowano szumy typu 1/f w elemencie wykazującym zjawisko elektrochromizmu - zmiany swoich parametrów optycznych (przezroczystości) pod wpływem przyłożonego napięcia. Element składał się z porowatej warstwy nanocząstek WO3 oraz tlenku Ni-V. Obserwowano gęstość widmową mocy prądu szumów, która zalezała liniowo od kwadratu prądu stałego I płynącego przez element. Stwierdzono, że intensywne przełączanie elementu między trybem przezroczystym...
-
Observations of Cepheids in Pi of the Sky experiment
Publication -
Local properties of the solution set of the operator equation in Banach spaces in a neighbourhood of a bifurcation point.
PublicationW niniejszej pracy badamy problem istnienia bifurkacji w zbiorze rozwiązań równania F(x,p)=0, gdzie F jest odwzorowaniem klasy C^2z iloczynu kartezjańskiego X i R^k do Y, X i Y są przestrzeniami Banacha takimi, że X jest podprzestrzenią liniową Y. Co więcej, dany jest iloczyn skalarny w Y, ciągły względem norm w X i Y. Pokazujemy, że pod pewnymi warunkami (0,p) jest punktem bifurkacji i opisujemyzbiór rozwiązań równania F(x,p)=0...
-
Fixed point theorems for weakly commuting and compatible multi-valued mappings.
PublicationW pracy podano twierdzenia o wspólnych punktach stałych czwórki odwzorowań: dwóch jednowartościowych T i S oraz dwóch wielowartościowych F i G, spełniających nieliniowy uogólniony warunek kontrakcyjny, przy pewnych założeniach dotyczących uogólnionej komutatywności T,S i F,G. W pracy zamieszczono przykłady ilustrujące udowodnione twierdzenia.
-
Airborne Laser Scanning Point Cloud Update by Used of the Terrestrial Laser Scanning and the Low-Level Aerial Photogrammetry
PublicationLaser scanning technology is a spatial information gathering technique which is commonly used all over the world. Systems where the red-light beam are used, are divided into: terrestrial, mobile and airborne scanning systems. The main differences between those are the accuracy, the data acquisition solution (f. e. in ALS and MLS besides of the laser scanner, the inertial navigation system is required) and the covered area in one...
-
Behavior of residual current devices at earth fault currents with DC component
PublicationLow-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing...
-
Hybridization-driven gap inU3Bi4Ni3: AB209iNMR/NQR study
Publication -
Effect of clonidine on growth hormone release in psychiatric patients and controls
Publication -
15 N NMR and FTIR studies of 2,4-dinitroanilines and their salts
Publication -
Frequency-Variant Double-Zero Single-Pole Reactive Coupling Networks for Coupled-Resonator Microwave Bandpass Filters
PublicationIn this work, a family of frequency-variant reactive coupling (FVRC) networks is introduced and discussed as new building blocks for the synthesis of coupled-resonator bandpass filters with real or complex transmission zeros (TZs). The FVRC is a type of nonideal frequency-dependent inverter that has nonzero elements on the diagonal of the impedance matrix, along with a nonlinear frequency-variation profile of its transimpedance...
-
Modeling the impact of rotor movement on non-linearity of motor currents waveforms in high-speed PMSM drives
PublicationMotor current measurement techniques as well as predictive control algorithms for electric drives rely on an assumption of linear motor currents changes resulting from constant inverter output voltages. Recent research has reported that this assumption does not hold in motors with short electrical time constant, and in drives whose rotor position advances substantially during a control period. This paper proposes a simulation model...
-
Singlet oxygen in the removal of organic pollutants: An updated review on the degradation pathways based on mass spectrometry and DFT calculations
PublicationThe degradation of pollutants by a non-radical pathway involving singlet oxygen (1O2) is highly relevant in advanced oxidation processes. Photosensitizers, modified photocatalysts, and activated persulfates can generate highly selective 1O2 in the medium. The selective reaction of 1O2 with organic pollutants results in the evolution of different intermediate products. While these products can be identified using mass spectrometry...
-
Generalized Gradient Equivariant Multivalued Maps, Approximation and Degree
PublicationConsider the Euclidean space Rn with the orthogonal action of a compact Lie group G. We prove that a locally Lipschitz G-invariant mapping f from Rn to R can be uniformly approximated by G-invariant smooth mappings g in such a way that the gradient of g is a graph approximation of Clarke’s generalized gradient of f . This result enables a proper development of equivariant gradient degree theory for a class of set-valued gradient...
-
New approach in determination of urinary diagnostic markers for prostate cancer by MALDI-TOF/MS
Publication -
Soil organic carbon, macro- and micronutrient changes in soil fractions with different lability in response to crop intensification
Publication -
The multiscalar control of induction motor with the sliding mode controllers
PublicationThe control structure of induction motor is proposed in this paper. The structure of multiscalar control with conventional PI - controllers is well known in literature. The sliding mode multiscalar control (SMMC) conception is presented in this paper. The induction motor is fed by voltage source inverter. Comparison between two multiscalar control method is showed.
-
Oversizing the photovoltaic generator capacity in a micro photovoltaic plant
PublicationA significant part of photovoltaic micro installations in Poland is characterized by photovoltaic generator oversizing in relation to the inverter. The idea of oversizing, however, still raises doubts among some plant owners. In the paper, the energy yield of installation with an oversized and not oversized photovoltaic generator is presented on selected examples, showing the legitimacy of oversizing.
-
Photocatalytical properties of maze-like MoO3 microstructures prepared by anodization of Mo plate
PublicationIn this work, we present a simple method of the formation of MoO3 microstructures via an electrochemical anodization of Mo plate carried out under varied conditions. The morphology, composition and structure of samples were investigated by SEM, EDX, XRD and Raman spectroscopy. The band gap energy was estimated using the Kubelka–Munk function and was found to be 2.87 eV. Finally, the photocatalytic activities of MoO3 samples were...
-
The basics of design and experimental tests of the commutation unit of a hydraulic satellite motor
Publicationhe article presents an analytical method to design the commutation unit in a hydraulic satellite motor. It is shown that the size of the holes feeding the working chambers and their location on the plates closing those chambers depends on the geometrical dimensions of the working mechanism. The overlap in the commutation unit depends on the rotational speed range. It is demonstrated that the geometrical dimensions of the commutation...
-
Measurements of flicker noise in supercapacitor cells
PublicationFlicker noise (1/f-like noise) is often used to assess the quality of various materials and devices. This phenomenon has been observed in different electrochemical devices or reactions (e.g., smart windows, pitting corrosion events). In our exploratory studies we consider how to measure and utilize 1/f noise for the quality assessment of supercapacitors. This task requires special attention because of enormous capacitance of the...
-
Algebraic periods and minimal number of periodic points for smooth self-maps of 1-connected 4-manifolds with definite intersection forms
PublicationLet M be a closed 1-connected smooth 4-manifolds, and let r be a non-negative integer. We study the problem of finding minimal number of r-periodic points in the smooth homotopy class of a given map f: M-->M. This task is related to determining a topological invariant D^4_r[f], defined in Graff and Jezierski (Forum Math 21(3):491–509, 2009), expressed in terms of Lefschetz numbers of iterations and local fixed point indices of...
-
Common-Mode Voltage and Bearing Currents in PWM Inverters: Causes, Effects and Prevention
PublicationIn modern induction motor drives an increase of transistors' switching frequency and a decrease of switching times are the sources of some serious problems. The high dv/dt and the common mode voltage generated by the inverter PWM control results in the appearances of bearing currents, shaft voltages, motor terminal overvoltages, the decrease of motor efficiency, and electromagnetic interference. The aspects of common mode (CM)...
-
Appendix E
PublicationThe advance of variable speed drives systems (VSDs) engineering highlights the need of specific technical guidance provision by electrical machines and drives manufacturers, so that such applications can be properly designed to present advantages in terms of both energy efficiency and expenditure. This book presents problems and solutions related to inverter-fed electrical motors. Practically orientated, the book describes the...
-
Space vector modulation in multilevel inverters of the servo drives of the trajectory measurements telescopes
PublicationUsing the MatLab/Simulink mathematical model of a three-phase three-level voltage inverter, the influence of the space-vector modulation (SVM) algorithm on the pulsations of the current (torque) of an AC motor in the range of low rotation speeds is considered. It is shown that the SVM of the second kind does not provide a pulsations level comparable to the pulsations of a sinusoidal pulse-width modulation (SPWM), both in the static...
-
A new fuzzy model of multi-criteria decision support based on Bayesian networks for the urban areas' decarbonization planning
Publication -
The first order phase transition and superconductivity in BaNi2As2single crystals
Publication -
Studies of complexation of metal cations by tris(3,6-dioxaheptyl)amine in solution
Publication -
Results from a geotechnical benchmark exercises of an embankment on softclay
PublicationZagadnienie brzegowo-początkowe przykładowego nasypu budowlanego na podłożu słabonośnym zostało rozwiązane przy pomocy różnych programów komputerowych opierających się na metodzie elementów skończonych. Zastosowano także różne modele konstytutywne opisujące zachowanie się jednorodnego podłoża słabonośnego. Wyniki obliczeń porównano analizując szczegółowo różnice oraz ich przyczyny. Przeprowadzona analiza jest cennym porównaniem...
-
Systems, Environments, and Soliton Rate Equations: Toward Realistic Modeling
PublicationIn order to solve a system of nonlinear rate equations one can try to use some soliton methods. The procedure involves three steps: (1) find a ‘Lax representation’ where all the kinetic variables are combined into a single matrix ρ, all the kinetic constants are encoded in a matrix H; (2) find a Darboux–Bäcklund dressing transformation for the Lax representation iρ˙=[H,f(ρ)], where f models a time-dependent environment; (3) find...
-
A new hyperbolic-polynomial higher-order elasticity theory for mechanics of thick FGM beams with imperfection in the material composition
PublicationA drawback to the material composition of thick functionally graded materials (FGM) beams is checked out in this research in conjunction with a novel hyperbolic‐polynomial higher‐order elasticity beam theory (HPET). The proposed beam model consists of a novel shape function for the distribution of shear stress deformation in the transverse coordinate. The beam theory also incorporates the stretching effect to present an indirect...
-
A Strategy to Locate Fixed Points and Global Perturbations of ODE’s: Mixing Topology with Metric Conditions
PublicationIn this paper we discuss a topological treatment for the planar system z' = f (t, z) + g(t, z) where f and g are T -periodic in time and g(t, z) is bounded. Namely, we study the effect of g(t, z) in two different frameworks: isochronous centers and time periodic systems having subharmonics. The main tool employed in the proofs consists of a topological strategy to locate fixed points in the class of orientation preserving embedding...
-
Awareness of Influenza and Attitude Toward Influenza Vaccination Among Medical Students
Publication -
Crystal fields, disorder, and antiferromagnetic short-range order in Yb0.24Sn0.76Ru
Publication -
Evaluation of the influence of grapevine growing conditions on wine quality
PublicationScientists are increasingly interested in the viticulture concept of terroir, which states that unique properties of wine are strictly related to the environmental conditions under which grapes are cultivated. The aim of the research was to compare the parameters characterizing wines produced in Poland, such as pH, conductivity, total organic carbon (TOC), and concentration of anions (F−, Cl−, NO2−, NO3−, PO43−, SO42−). It was...
-
External Validation Measures for Nested Clustering of Text Documents
PublicationAbstract. This article handles the problem of validating the results of nested (as opposed to "flat") clusterings. It shows that standard external validation indices used for partitioning clustering validation, like Rand statistics, Hubert Γ statistic or F-measure are not applicable in nested clustering cases. Additionally to the work, where F-measure was adopted to hierarchical classification as hF-measure, here some methods to...
-
Invariant Measures for Uncountable Random Interval Homeomorphisms
PublicationA necessary and sufficient condition for the iterated function system { f (·, ω) | ω ∈ } with probability P to have exactly one invariant measure μ∗ with μ∗((0, 1)) = 1 is given. The main novelty lies in the fact that we only require the transformations f (·, ω) to be increasing homeomorphims, without any smoothness condition, nei- ther we impose conditions on the cardinality of . In particular, positive Lyapunov exponents conditions...
-
Slurry Surfacing Mixes on the Basis of Bitumen Modified with Phenol-Cresol-Formaldehyde Resin
PublicationSlow-breaking monophase cationic bitumen emulsions have been produced on the basis of bitumen modified with phenol-cresol-formaldehyde resin (PhCR-F). Bitumen emulsions were used as a binder for thin-layer coatings with slurry surfacing mixes (SSM). Physical and technical parameters of modified and unmodified emulsions were determined and analyzed. The optimal compositions of SSM were selected according to the breaking criterion....