Filtry
wszystkich: 446
wybranych: 405
-
Katalog
Filtry wybranego katalogu
Wyniki wyszukiwania dla: STABILITY CONTROL
-
Can we really solve an arch stability problem?
PublikacjaWe bring attention to the problem of solving nonlinear boundary-value problems for elastic structures such as arches and shells. Here we discuss a classical problem of a shear-deformable arch postbuckling. Considering a postbuckling behaviour of a circular arch we discuss the possibility to find numerically a solution for highly nonlinear regimes. The main attention is paid to the problem of determination of all solutions. The...
-
Stability by linear approximation for time scale dynamical systems
PublikacjaWe study systems on time scales that are generalizations of classical differential or difference equations and appear in numerical methods. In this paper we consider linear systems and their small nonlinear perturbations. In terms of time scales and of eigenvalues of matrices we formulate conditions, sufficient for stability by linear approximation. For non-periodic time scales we use techniques of central upper Lyapunov exponents...
-
Stability criteria as constraints in a fleet of ships optimisation problem
PublikacjaRozwiązano problem dotyczący matematycznej optymalizacji floty statków wielozadaniowych typu rzeka-morze, przeznaczonych dla europejskiej żeglugi przybrzeżnej i eksploatowanych w obszarze Mórz Północnego i Bałtyckiego, na poziomie zadania transportowego za pomocą metod programowania nieliniowego z ograniczeniami. Zaproponowano metodę włączenia istniejących kryteriów skuteczności statków jako ograniczeń w ogólnym modelu optymalizacji...
-
Stability analysis of cylindrical composite shells in MSC/Nastran
PublikacjaW pracy badane jest zastosowanie systemu MSC/NASTRAN for Windows do analizy stateczności kompozytowych powłok cylindrycznych. Przeprowadzono obliczenia dla dwóch wybranych przykładów paneli cylindrycznych poddanych równomiernemu ściskaniu w kierunku tworzącej dokonując analizy zarówno w zakresie stateczności początkowej jak i problemu geometrycznie nieliniowego w procesie przyrostowym. Otrzymane wyniki w pełni potwierdziły bogate...
-
Prediction of the motion stability of three-wheel mobile robot
PublikacjaW pracy rozważa się projektowanie i realizację trajektorii ruchu 3-kołowego robota mobilnego, z uwzględnieniem jego kinematyki i dynamiki. Kołowe roboty mobilne zaliczane są do układów nieholonomicznych, w przypadku których przyjęte ograniczenia (więzy) dotyczą chwilowych prędkości punktów charakterystycznych układu. Model matematyczny obiektu przedstawiono w postaci skończonej liczby nieliniowych równań różniczkowych kinematyki...
-
The Influence of the Cuboid Float’s Parameters on the Stability of a Floating Building
PublikacjaUsually, the concept of sufficient stability of a floating structure is connected with the capacity to keep a small heel angle despite the moment of heeling. The variable responsible for these characteristics is the initial metacentric height, which is the relation between the hydrostatic features of the pontoon and the mass properties of the entire object. This article answers the questions of how heavy the floating system should...
-
Selected Stability Problems of Thin-Walled Columns and Beams
PublikacjaThe article reviews a number of papers in the light of buckling analy- sis of thin-walled columns and beams. Stability of thin-walled columns and beams are considered a vital engineering science issue in both historical and present-day approaches. The paper refers to the recent authors’ works of the 2012–2019 period, published in leading journals. Similar review of stability problems of thin-walled structures developed at Gdansk...
-
Rigid polyurethane foams modified with selected flame retardants
PublikacjaThe flame retardants: expandable graphite, triethylphosphatehas been used in rigid polyurethane foams (PUFs). The influence of fillers amounts on processing parameters, physical-mechanical properties (compression strength, density, water absorption, brittleness)and thermal properties (thermal stability) of such foams has been analyzed.The gel, cram and rise time for PUFs modified with flame retardant has been observed during synthesis...
-
High Efficiency Dual-Active-Bridge Converter with Triple-Phase-Shift Control for Battery Charger of Electric Vehicles
PublikacjaAn optimal modulation scheme with triple-phase-shift (TPS) control could increase the efficiency in the entire load range for a dual-active-bridge (DAB) converter under wide output voltage range conditions. Therefore, this study proposes a convergent approach to TPS mode selection, coupled with an optimal modulation scheme, ensuring the circuit’s efficiency over the entire range in the realm of a high-power and high-efficiency...
-
Z type Observer Backstepping For Induction Machines
PublikacjaThis paper contains a relatively new synthesis method for non-linear objects, named backstepping. This method can be used to obtain the observer structure. The paper presents the structure of the speed observer which is a new proposition of observer backstepping with additional state variables marked Z. The rotor speed can be estimated in three different ways. The first is based on the adaptive approach, the second on the nonadaptive...
-
Quantitative determination of mechanical stability in the novel coronavirus spike protein
Publikacja -
Magnetically induced dynamical stability of a Fe monolayer on W(110)
Publikacja -
Wettability and Stability of Naproxen, Ibuprofen and/or Cyclosporine A/Silica Delivery Systems
Publikacja -
Ridging, strength, and stability in high-resolution sea ice models
Publikacja -
On convergence and stability of a numerical scheme of Coupled Nonlinear Schrödinger Equations
PublikacjaRozważamy rozwiązania numeryczne układu sprężynowych równań nieliniowych Schrödingera. Udowodniliśmy stabilność i zbieżność. Testujemy za pomocą rozwiązań solitonowych.
-
The work of Professor Andrzej Lasota on asymptotic stability and recent progress
PublikacjaPraca poświęcona jest wkładowi Profesora Andrzeja Lasoty w teorię asymptotycznej stabilności iteracji operatorów stochastycznych na przestrzeni ostatnich 36 lat. Podkreślono aplikacyjny charakter wyników, pokazując stosowne przykłady z modelowania rozwoju komórki, optymalizacji wierceń geologicznych i ewolucji modeli kwantowych.
-
The stability of a damaged roll-on roll-off vessel with water on deck
PublikacjaPrzeprowadzono analizę stateczności statku ro-ro w stanie awaryjnym z wodą na pokładzie. Pokazano, że moment przechylający związany jest z wypiętrzeniem wody na pokładzie ponad poziom wody zaburtowej, pochodzącym od fali. Omówiono trzy metody wyznaczania kąta przechyłu, wywołanego wodą na pokładzie. Zidentyfikowano krytyczne wypiętrzenie wody, przy którym następuje utrata stateczności statku.
-
Effect of Newly Created Water Reservoirs on Agricultural Landscape Stability
Publikacja -
N6-methyladenosine regulates the stability of RNA:DNA hybrids in human cells
Publikacja -
THE INFLUENCE OF PHASE SHIFTERS ON THE VOLTAGE STABILITY OF CONNECTED POWER SYSTEMS
PublikacjaThe paper presents the results of simulation tests of connected power systems in which phase shifters were installed on cross-border links. The analysis was carried out in terms of assessing the impact of shifters on node voltage stability. Individual systems were characterized by different balance of active power: deficit or excess. The evaluation of voltage stability was based on the dU/dQ and dU/dP criteria.
-
Experimental study of the effect of vertical acceleration component on the slope stability
PublikacjaThe paper deals with the stability of earth dams subjected to seismic and paraseismic excitations occurring in the close distance to the dam. The Newmark’s stability approach, classified as a simplified dynamic method, has been extended for two directional dynamic loading case and the evolution of the friction coefficient. The paper is focused on the experimental verification of the proposed method for harmonic and cyclic excitations...
-
Real-Time stability monitoring for expansion of the UCTE synchronous area
PublikacjaW referacie przedstawiono zasady wykorzystania systemu WAMS dla potrzeb oceny zapasu stabilności lokalnej systemu elektroenergetycznego.
-
Studies on the influence of β-cyclodextrin derivatives on the physical stability of famotidine
PublikacjaThe usage of Fourier transform infrared spectroscopy, near infrared spectroscopy, differential scanning calorimetry and microscopy is presented in this work focused on the exploration of the effect of CD on the physical stability of famotidine (FAM). The most significant information was achieved by analysis of the second derivatives ofnear infrared (NIR) spectra recorded. Changes in the shape of spectra derivatives allow...
-
Rheological properties and stability of water in Canola oil ethyl esteremulsion.
PublikacjaWyznaczono krzywe płynięcia i podatność na rozdział dla emulsji fazy wodnej w estrze etylowym oleju Canola. Właściwości te stanowią o podatności tej emulsji jako symulanta ropy naftowej w badaniach terenowych rozlewów olejowych.
-
Preliminary experimental research on stability of truss' joint with positive eccentricity
PublikacjaRecently, a very large interest in lightweight steel structures made from cold-formed sections has been noticeable. In the design practice, a large emphasis is put on rational shaping of both the thin-walled elements and constructions designed on them. The aim of this paper is to present the methodology for preparation of experimental research that model the behaviour of members in trusses made of cold-formed sections with positive...
-
Investigation of stability and limit load of a truss overhead opened bridge
PublikacjaThe paper presents selected methods of determining stability and limit load of a truss top chord in opened bridges. These methods include linear buckling and non-linear static analysis based on the finite element method and algorithms based on design code procedures. The described methods were tested on an example of a steel footbridge situated in Straszyn. The results of stability analysis are compared. The results of geometrical...
-
EFFECT OF PRESS DRYING ON DIMENSION STABILITY AND DENSITY OF BEECH WOOD,
PublikacjaTimber is traditionally dried in kilns by processes that often take several days or weeks to complete. At present, it is possible to apply several methods of rapid drying of timber, including, for example, press drying. This research is based on the use of this process. Drying was performed using the heating plates with a temperature of 160 °C. Three pressures were compared in the research 1.0 MPa, 1.4 MPa, and 1.8 MPa. The density...
-
Group 11 complexes with a phosphanylphosphaalkene ligand: preparation and stability study
PublikacjaThe reactivities of two selected phosphanylphosphaalkenes, Ph2C=P-PtBu2 (1a) and (p-MeO-Ph)2C=P-PtBu2 (1b), toward CuCl, AgCl and (tht)AuCl (tht = tetrahydrothiophene) were investigated. As a result, new phosphanylphosphaalkene dimeric and monomeric complexes were formed (Cu and Ag dimeric and Au monomeric). All obtained products were air and moisture stable and light insensitive.
-
Temperature influences on shear stability of a nanosize plate with piezoelectricity effect
PublikacjaPurpose The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment. Design/methodology/approach Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account...
-
The Influence of Storage on Human Milk Lipidome Stability for Lipidomic Studies
PublikacjaHuman milk (HM) lipidome stability during storage is crucial in lipidomic studies to avoid misinterpretations. Facing the lack of comprehensive work on the HM lipidome stability, we performed a study on a potential alteration in the lipid profiles of HM samples stored under different conditions. An untargeted LC-Q-TOF-MS-based approach was applied to study the influence of storage conditions as well as the interaction of the storage...
-
A Method of Assessment of the Liquid Sloshing Impact on Ship Transverse Stability
PublikacjaLiquid sloshing phenomenon taking place in partly filled ships? tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic heeling moment due to liquid sloshing in tanks onboard ships. The set of numerical simulations of liquid...
-
Effect of excitation intensity on slope stability assessed by a simplified approach
PublikacjaThe paper concerns the selection of a design accelerograms used for the slope stability assessment under earthquake excitation. The aim is to experimentally verify the Arias Intensity as an indicator of the excitation threat to the slope stability. A simple dynamic system consisting of a rigid block on a rigid inclined plane subjected to horizontal excitation is adopted as a slope model. Strong ground motions recorded during earthquakes...
-
CAES – Energy storage providing stability for national power system
PublikacjaThis paper presents a short characteristics of the power system. It also describes various types of energy storage technologies. The suggested solution of accumulation and generation of electric power is based on the cooperation of gas turbine with Compressed Air Storage Energy systems – CAES. This analysis describes also various types of cooperation of CAES and renewable sources of energy, particularly wind power systems.
-
Stability analyses of a cylindrical steel silo with corrugated sheets and columns
PublikacjaW artykule przedstawiono wyniki obliczeń stateczności silosów z blachy falistej ze słupami. Wykonano analizy linowe i analizy nieliniowe stosując metody elementów skończonych. W obliczeniach uwzględniono model przestrzenny powłokowy oraz uproszczony model przestrzenny z blachy ortotropowej z belkami. Wyniki numeryczne porównano z Eurokodem.
-
Non-Adaptive Speed and Position Estimation of Doubly-Fed Induction Generator in Grid-Connected Operations
PublikacjaThe nonadaptive speed and position estimation scheme for a doubly-fed induction generator (DFIG) is presented in this article. The observer structure is based on the extension of the mathematical model of DFIG to the introduced H vector. Based on the defined H vector, the nonadaptive position and speed estimation is proposed. The Lyapunov method is extended to the practical stability theorem to stabilize the structure. The classic...
-
rigid polyurethane foams modified with selected nanofillers
PublikacjaThe nanofillers: natural montmoryllonite (MMT) - Bentonite, natural MMT modified with a quaternary ammonium salt - Cloisite30B, has been used in rigid polyurethane foams (PUFs). The influence of fillers amounts on processing parameters, physical-mechanical properties (density, water absorption, brittleness and compression strength) and thermal properties (thermal stability, fire behaviours) of such foams has been analysed. The...
-
Mechanical Design, Construction and Control of a Lower Extremity Exoskeleton Robot Prototype with a new structure in the form of three-wheeled Mobile robot
PublikacjaIn this paper, mechanical design, dynamic modeling, construction and Fuzzy computed torque control of a lab prototype of lower extremity exoskeleton robot with a new structure in the form of three-wheeled Mobile robot is presented. One of the most important applications of next generation of lower extremity exoskeleton robot is usability as smart vehicle. In order to autonomously moving of this robot which is the foundation...
-
A New Fuzzy Sliding Mode Controller with PID Sliding Surface for Underwater Manipulators
PublikacjaDesign of an accurate and robust controller is challenging topic in underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the control...
-
Stability of Diodes with Poly(3-hexylthiophene) and Polyazomethines Thin Organic Layer
Publikacja -
Enhancement of the structure stability of MOF‐5 confined to multiwalled carbon nanotubes
Publikacja -
Physicochemical Characteristics of Chitosan–TiO2 Biomaterial. 1. Stability and Swelling Properties
Publikacja -
Chemical and thermal stability of core-shelled magnetite nanoparticles and solid silica
Publikacja -
Influence of Antimony Substitution on Spontaneous Strain and Thermodynamic Stability of Lanthanum Orthoniobate
PublikacjaThe analysis of the antimony substitution influence on temperature dependence of unit cell distortion has been done. The values of spontaneous strain and Landau order parameter for three different antimony contents varied had been calculated. The phase transition occurring for antimony substituted lanthanum orthoniobate was found to be second order. The high temperature solution calorimetry method has been used to investigate...
-
On stability of iodine doped TiO2 electrodes in pH varied aqueous electrolytes
PublikacjaW pracy przedstaiono charakterystykę elektrochemiczną warstwy domieszkowanego jodem TiO2 na podłożu platynowym. Wyniki badań prowadzone w elektrolitach o różnym pH pozowoliły na określenie właściwości na granicy faz elektroda - elektrolit. Wyznaczono zależność potencjału pasma płaskiego od pH elektrolitu, a charakter otrzymanej funkcji potwirdził stabilność proszku I-TiO2 w kontakcie s roztworem.
-
Thermal Stability of Multicomponent Layers Created with the Hybrid Method on Aluminium Base
PublikacjaW pracy przedstawiono skład fazowy, mikrostrukturę oraz graficzny i matematyczny opis kinetyki utleniania wieloskładnikowych warstw powierzchniowych wytworzonych na aluminiowym podłożu.
-
Slope Stability Analysis of Zoned Earth Dam with RCC Overtopping Protection
Publikacja -
Stability and initial post-buckling behaviour of frame system with vertical bracings
PublikacjaStalowe hale są budowane jako układ ram płaskich połączonych stężeniami dachowymi i stężeniami pionowymi w postaci krzyżujących się prętów. W pracy przedstawiono analizę stateczności i zachowania pokrytycznego takiego układu poddanego działaniu obciążeń pionowych. Korzystając z warunków stacjonarności całkowitej energii potencjalnej wykazano, że punkt bifurkacji utraty stateczności jest niesymetryczny i niestateczny. Oznacza to,...
-
Stability of liquid film formed due to impingement of a two-phase jet
PublikacjaPrzedstawiono analizę teoretyczną i badania eksperymentalne zjawiska rozrywania się warstwy cieczy powstałej na powierzchni ciała stałego z uderzającej strugi.
-
Silica xerogel-hydrogen peroxide composite: their morphology, stability, and antimicrobial activity
PublikacjaOpracowano metody otrzymywania stabilnego kompozytu złożonego z kserożelu krzemionkowego i nadtlenku wodoru w szerokim zakresie stężeń H2O2. Przeprowadzono charakterystykę otrzymanego kompozytu. W szczególności określono morfologię kompozytu, stabilność termiczną oraz dokonano oceny właściwości bakteriobójczych preparatu.
-
Stability of an optical displacement sensor using a two-beam polarization interferometer
PublikacjaW artykule przedstawiono wyniki pomiarów stabilności wybranej konfiguracji dwuwiązkowego interferometru polaryzacyjnego. Przedyskutowano źródła występującej niestabilności.