Filtry
wszystkich: 1239
wybranych: 1171
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: STABILITY
-
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.
-
Pre-arrangement of solvability, complexity, stability and quality of GPC systems
PublikacjaPraca dotyczy podstawowych problemów strojenia algorytmów dyskretnoczasowego uogólnienia sterowania predykcyjnego (GPC). Optymalne sterowanie predykcyjne, w sensie pewnego kwadratowego funkcjonału kosztów, wyznacza się rozwiązując odpowiednie liniowe zadanie. W pracy podano warunki, przy których macierz tego zadania jest macierzą o pełnym kolumnowym rzędzie - co gwarantuje istnienie optymalnego sterownika. W następnej kolejności...
-
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.
-
Multimachine power system stability improvement using fuzzy control.
PublikacjaW celu poprawienia stabilności dynamicznej turbogeneratora i powiększenia tłumienia kołysań elektromechanicznych opracowano regulator napięcia wraz z stabilizatorem systemowym z wykorzystaniem teorię zbiorów rozmytych. Efektywność opracowanego rozmytego algorytmu oceniono w układzie wielomaszynowym.
-
Stability and limit load analysis of a cold-formed channel section column
PublikacjaThe paper presents stability and limit load analysis of a steel column 1440 mm high of a cold-formed channel section, subjected to a combination of compression and bending. Experimental results were compared to the resistance of a code procedure and to the outcome of numerical non-linear analysis. Comparison was made of numerical solutions by means of static (Riks) and dynamic (Explicit and Implicit) methods. Perfectly elastic...
-
LINEAR CHARACTERISTICS OF THE SLOSHING PHENOMENON FOR THE PURPOSE OF ON-BOARD SHIP'S STABILITY ASSESSMENT
PublikacjaThe paper presents results of experimental research and numerical simulations of the sloshing phenomenon. The research was focused on computation of the heeling moment affecting stability of a vessel. The proposed linearisation enables application of the results to the assessment of the ship's stability. The dependence of the heeling moment upon localisation of a tank in the ship's hull is analysed. The heeling moment obtained...
-
Effect of vehicle motion stability after impact/crash on traffic safety
PublikacjaThe article presents the application of general stability theory to the study of road traffic stability immediately after an impact (crash, collision). It turns out that when modelling a collision, vehicles can be treated as colliding masses and dynamical systems can be assigned to this phenomenon.
-
STABILITY OF THE INNER SLOPE OF THE POLISH DREDGDIKES RESEARCH DIKE AT STATIONARY FLOW
PublikacjaFor long duration of the flood the water table can appear on the slope with a problem of out-wash in the case of sand type dike. If the dike corps is covered with less permeable layer some additional push-off forces and shearing can rise in the cover. In both cases the micro stability of the inner slope should be considered at normative high water for homogeneous sand type dike or sand type dike with less permeable covers. The...
-
Geotechnical Analysis and Stability Assessment of a Landslide Event in Gera Woreda, Ethiopia
PublikacjaThis study investigates the geotechnical factors influencing a recent landslide event in Gera Woreda, Ethiopia. The primary objective was to identify the soil properties contributing to landslide occurrence and understand the triggering mechanisms. Field investigations, soil sampling from both affected and unaffected areas, and subsequent laboratory characterization were conducted. The analysis revealed a dominance of fine-grained...
-
Stability analysis of a road scarp in the Carpathian Mountains and methods of its protection
PublikacjaThe purpose of the study was to analyse the stability of a road scarp endangered by a landslide and to consider some measures for its stabilization. The potential landslide could unfavourably alter the shape of the slope, thus a religious sanctuary situated above the slope. The present research has resulted in suggestions of possible protection methods, namely, drainage, soil nailing, installation of piles, supporting the scarp...
-
Experimental and numerical study on stability loss of innovative geometry steel girder
PublikacjaThis paper presents the experimental and numerical analysis of an innovative plate girder geometry with variable web thicknesses. An idea proposed in this research is to increase the stability of the girder web by increasing its thickness in the compressed zone. This solution can replace commonly used longitudinal stiffeners which are designed to prevent web local loss of stability. Moreover, such an innovative approach requires...
-
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...
-
Testing Stability of Digital Filters Using Optimization Methods with Phase Analysis
PublikacjaIn this paper, novel methods for the evaluation of digital-filter stability are investigated. The methods are based on phase analysis of a complex function in the characteristic equation of a digital filter. It allows for evaluating stability when a characteristic equation is not based on a polynomial. The operation of these methods relies on sampling the unit circle on the complex plane and extracting the phase quadrant of a function...
-
Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublikacjaThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
-
On thermal stability of piezo-flexomagnetic microbeams considering different temperature distributions
PublikacjaBy relying on the Euler–Bernoulli beam model and energy variational formula, we indicate critical temperature causes in the buckling of piezo-flexomagnetic microscale beams. The corresponding size-dependent approach is underlying as a second strain gradient theory. Small deformations of elastic solids are assessed, and the mathematical discussion is linear. Regardless of the pyromagnetic effects, the thermal loading of the thermal...
-
EFFECT OF ANTIOXIDANTS ON THE STABILITY OF PITCH- BASED POLYMER TO THERMO-OXIDATIVE ACTION
PublikacjaThe influence of stabilizers – hydrogen donors – on the processes of thermooxidative destruction of pitch-based polymer has been investigated. It is shown that Irganox has not stabilizing effect on pitch-based polymer and melamine slightly retards the destructive process. A mixture of melamine and Irganox exhibits synergetic stabilizing effect and at the optimum ratio it can be used to prevent unwanted thermooxidative processes...
-
Silica xerogel–hydrogen peroxide composites: Their morphology, stability, and antimicrobial activity
Publikacja -
Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublikacjaThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
-
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.
-
Stability of truss with side - supports. The case of linear and rotational elastic supports
PublikacjaThe research is devoted to study lateral buckling of truss with linear and rotational elastic side-supports. Geometrically nonlinear analysis of example truss with linear and rotational elastic sidesupports is carried out. The limit normal force in compressed chord of the truss due to stiffness of side supports is calculated. The elastic support reaction in relation to force in compressed chordand coefficient of buckling length...
-
Estimating Regions of Absolute Stability with the Use of Piecewise Linear Lyapunov Functions
Publikacja -
Influence of Drainage on Peat Organic Matter: Implications for Development, Stability, and Transformation
Publikacja -
Slope Stability Analysis of Zoned Earth Dam with RCC Overtopping Protection
Publikacja -
Fluorinated Boronic Acids: Acidity and Hydrolytic Stability of Fluorinated Phenylboronic Acids
Publikacja -
Amphenicols stability in medicated feed – development and validation of liquid chromatography method
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 -
Prediction of the stability during optimal control of the 3-wheel mobile platform
PublikacjaW pracy przedstawiono metodę badania stabilności sterowania optymalnego 3-kołową platformą mobilną podczas realizacji zadanej trajektorii ruchu. Badany robot posiada więzy nieholonomiczne. Model matematyczny robota 3-kołowego opisano za pomocą skończonej liczby nieliniowych równań różniczkowych. Stąd, prognozowanie ruchu takiego obiektu wymaga zastosowania efektywnych algorytmów.
-
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.
-
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.
-
Stability of delay induced oscillations in gene expression of Hes1 protein model
PublikacjaW pracy prezentowana jest matematyczna analiza modelu ekspresji genu białka Hes1. Rozważamy układ równań z dwoma opóźnieniami - w produkcji białka Hes1 oraz jego mRNA. Dowodzimy istnienia i jednoznaczności oraz nieujemności rozwiązań. Pokazujemy istnienie dokładnie jednego dodatniego stanu stacjonarnego. Wykazujemy, że stabilność stanu stacjonarnego zależy od sumy opóźnień. Podajemy warunek dostateczny na wystąpienie bifurkacji...
-
Analysis of differences in the stability of proteins encoded in mitochondrial DNA of model organisms
Publikacja -
Liposomal Nanoformulation as a Carrier for Curcumin and pEGCG—Study on Stability and Anticancer Potential
Publikacja -
Seed-Roasting Process Affects Oxidative Stability of Cold-Pressed Oils
Publikacja -
Stability of Diodes with Poly(3-hexylthiophene) and Polyazomethines Thin Organic Layer
Publikacja -
Chemical and thermal stability of core-shelled magnetite nanoparticles and solid silica
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,...
-
Simplified numerical model for global stability of corrugated silos with vertical stiffeners
PublikacjaArtykuł omawia wyniki stateczności globalnej silosów z blachy falistej z pionowymi usztywnieniami. Zaproponowano uproszczony model numeryczny metody elementów skończonych do określenia stateczności. Wyniki numeryczne były bardziej dokładnie niż metody zaproponowane w Eurokodzie.
-
Liquid-liquid separation in petroleum production: ultrasonic characterization of emulsion stability.
PublikacjaPrzedstawiono nowe urządzenie pozwalające monitorować rozdział emulsji za pomocą ultradźwięków. Wykonano kalibrację, dzięki której można sygnał szybkości rozchodzenia się dźwięków przekształcać na stężenie fazy wewnętrznej emulsji oraz otrzymywać wykres rozdziału faz w czasie. Wyniki otrzymano dla modelowej emulsji typu O/W, w której fazę olejową stanowił bitumen oraz dla emulsji W/O, gdzie fazą olejową była ropa naftowa
-
Banking stability during the economic transformation process in selected countries of the Western Balkans
PublikacjaEconomic transformation is still an ongoing process in many European countries. Despite common economic roots, the current economic situations are developing differently in different countries. This article will consider the process of economic transformation in terms of the banking sector. It aims to assess the level of banking stability throughout the transformation process in the Western Balkan region, and to assess the determinates...
-
The Impact of Sloshing Liquids on Ship Stability for Various Dimensions of Partly Filled Tanks
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. A number of numerical simulations of liquid...
-
Effect of gelation and storage conditions on the oxidative stability of microemulsion and nanoemulsion delivery systems
PublikacjaIncreased interest in the use of microemulsion and nanoemulsion delivery systems for medical, cosmetic and food purposes, promotes the development of research on their physical and chemical stability, and the safety of use. Here, we have for the first time evaluated the oxidative stability of linseed oil dispersed in the microemulsion, nanoemulsion, and their gelled systems, stored under different conditions, and compared to the...
-
General Mechanism of Osmolytes’ Influence on Protein Stability Irrespective of the Type of Osmolyte Cosolvent
PublikacjaThe stability of proteins in an aqueous solution can be modified by the presence of osmolytes. The hydration sphere of stabilizing osmolytes is strikingly similar to the enhanced hydration sphere of a protein. This similarity leads to an increase in the protein stability. Moreover, the hydration sphere of destabilizing osmolytes is significantly different. These solutes generate in their surroundings so-called “structurally different...
-
Strong ellipticity conditions and infinitesimal stability within nonlinear strain gradient elasticity
PublikacjaWe discuss connections between the strong ellipticity condition and the infinitesimal instability within the nonlinear strain gradient elasticity. The strong ellipticity (SE) condition describes the property of equations of statics whereas the infinitesimal stability is introduced as the positive definiteness of the second variation of an energy functional. Here we establish few implications which simplify the further analysis...
-
On FEM analysis of Cosserat-type stiffened shells. Static and stability linear analysis
PublikacjaThe present research investigates the theory and numerical analysis of shells stiffened with beams in the framework based on the geometrically exact theories of shells and beams. Shell’s and beam’s kinematics are described by the Cosserat surface and the Cosserat rod respectively, which are consistent including deformation and strain measures. A FEM approximation of the virtual work principle leads to the conforming shell and beam...
-
Reliability-Based Stability Analysis of a Baltic Cliff by the Combined Response Surface Method
PublikacjaA simple, straightforward computational procedure was proposed, incorporating the Response Surface Method (RSM) linked with the standard Monte Carlo (MC) simulation method and the Point Estimate Method (PEM). PEM samples make it possible to analyse the sensitivity of the cliff’s stability to variation in subsoil parameters and to reduce the number of random variables of the problem. The proposed methods were tested in two cases:...
-
Large thermo-elastic displacement and stability FEM analysis of multilayered plates and shells
PublikacjaThe paper concerns the load capacity analysis of thermally loaded multilayered plates and shells. The multilayered body is treated as an equivalent single layer whose kinematics is consistent with first order shear deformation theory. The authors focus on the thermo-elastic stability problem of the thin-walled structures. The equilibrium paths are traced with the use of Riks-Wempner-Ramm algorithm. By making use of the Tsai-Wu...
-
Porous Phantoms Mimicking Tissues—Investigation of Optical Parameters Stability Over Time
PublikacjaOptical phantoms are used to validate optical measurement methods. The stability of their optical parameters over time allows them to be used and stored over long-term periods, while maintaining their optical parameters. The aim of the presented research was to investigate the stability of fabricated porous phantoms, which can be used as a lung phantom in optical system. Measurements were performed in multiple series with an interval...